Publications by category
Journal articles
Pérez G, O'Leary BC, Allegri E, Casal G, Cornet CC, de Juan S, Failler P, Fredriksen S, Fonseca C, Furlan E, et al (2024). A conceptual framework to help choose appropriate blue nature-based solutions.
J Environ Manage,
352Abstract:
A conceptual framework to help choose appropriate blue nature-based solutions.
Biodiversity loss and climate change have severely impacted ecosystems and livelihoods worldwide, compromising access to food and water, increasing disaster risk, and affecting human health globally. Nature-based Solutions (NbS) have gained interest in addressing these global societal challenges. Although much effort has been directed to NbS in urban and terrestrial environments, the implementation of NbS in marine and coastal environments (blue NbS) lags. The lack of a framework to guide decision-makers and practitioners through the initial planning stages appears to be one of the main obstacles to the slow implementation of blue NbS. To address this, we propose an integrated conceptual framework, built from expert knowledge, to inform the selection of the most appropriate blue NbS based on desired intervention objectives and social-ecological context. Our conceptual framework follows a four incremental steps structure: Step 1 aims to identify the societal challenge(s) to address; Step 2 highlights ecosystem services and the underlying biodiversity and ecological functions that could contribute to confronting the societal challenge(s); Step 3 identify the specific environmental context the intervention needs to be set within (e.g. the spatial scale the intervention will operate within, the ecosystem's vulnerability to stressors, and its ecological condition); and Step 4 provides a selection of potential blue NbS interventions that would help address the targeted societal challenge(s) considering the context defined through Step 3. Designed to maintain, enhance, recover, rehabilitate, or create ecosystem services by supporting biodiversity, the blue NbS intervention portfolio includes marine protection (i.e. fully, highly, lightly, and minimally protected areas), restorative activities (i.e. active, passive, and partial restoration; rehabilitation of ecological function and ecosystem creation), and other management measures (i.e. implementation and enforcement of regulation). Ultimately, our conceptual framework guides decision-makers toward a versatile portfolio of interventions that cater to the specific needs of each ecosystem rather than imposing a rigid, one-size-fits-all model. In the future, this framework needs to integrate socio-economic considerations more comprehensively and be kept up-to-date by including the latest scientific information.
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Author URL.
Ayres KA, Lara-Lizardi F, Roberts CM, Pisco-Limones W, Klimley P, Jorgensen SJ, Galván-Magaña F, Hoyos-Padilla M, Ketchum JT (2024). Local diver knowledge reveals decline in scalloped hammerhead sharks (Sphyrna lewini) at seamounts in the southwestern Gulf of California.
Marine Policy,
159Abstract:
Local diver knowledge reveals decline in scalloped hammerhead sharks (Sphyrna lewini) at seamounts in the southwestern Gulf of California
The Gulf of California is a marginal sea that has seen widespread species declines due to fishing. The scalloped hammerhead shark (Sphyrna lewini) is a semi-pelagic species that form large schools at seamounts where they refuge during the day. El Bajo seamount off Espíritu Santo Island and Las Animas seamount off San José Island in the southern Gulf of California are long-established scuba-dive destinations for observing S. lewini. In this study local scuba-diver knowledge was used to determine changes in S. lewini school abundance over a 50 year period between 1970 and 2020. The abundance of S. lewini encountered per dive at El Bajo was reported to have significantly declined, falling by 97%, from an average of 150 sharks in the 1970 s to 5 sharks in the 2010 s and at Las Animas by 100%, from an average of 100 sharks in the 1970 s to 0 sharks in the 2010 s. A shifting baseline was evident and there was a significant relationship between the year participants had first dived the seamounts and the number they considered to be a ‘very abundant’ school of S. lewini (GAM p < 0.001). This study demonstrates the importance of collecting local ecological knowledge to document declines in species populations, especially for S. lewini which is currently listed as ‘Critically Endangered’ on the IUCN Red List.
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Epstein G, Roberts CM (2023). Does biodiversity-focused protection of the seabed deliver carbon benefits? a UK case study.
CONSERVATION LETTERS,
16(1).
Author URL.
O'Leary BC, Fonseca C, Cornet CC, de Vries MB, Degia AK, Failler P, Furlan E, Garrabou J, Gil A, Hawkins JP, et al (2023). Embracing Nature-based Solutions to promote resilient marine and coastal ecosystems. Nature-Based Solutions, 3, 100044-100044.
Fonseca C, Wood LE, Andriamahefazafy M, Casal G, Chaigneau T, Cornet CC, Degia AK, Failler P, Ferraro G, Furlan E, et al (2023). Survey data of public awareness on climate change and the value of marine and coastal ecosystems. Data in Brief, 47
Rogers AD, Appeltans W, Assis J, Ballance LT, Cury P, Duarte C, Favoretto F, Hynes LA, Kumagai JA, Lovelock CE, et al (2022). Discovering marine biodiversity in the 21st century. , 93, 23-115.
Epstein G, Roberts CM (2022). Identifying priority areas to manage mobile bottom fishing on seabed carbon in the UK. PLOS Climate, 1(9).
Laffoley D, Baxter JM, Amon DJ, Claudet J, Downs CA, Earle SA, Gjerde KM, Hall-Spencer JM, Koldewey HJ, Levin LA, et al (2022). The forgotten ocean: Why COP26 must call for vastly greater ambition and urgency to address ocean change.
Aquatic Conservation: Marine and Freshwater Ecosystems,
32(1), 217-228.
Abstract:
The forgotten ocean: Why COP26 must call for vastly greater ambition and urgency to address ocean change
Of all the interconnected threats facing the planet, the top two are the climate and the biodiversity crises. Neither problem will be solved if we ignore the ocean. To turn the tide in favour of humanity and a habitable planet, we need to recognize and better value the fundamental role that the ocean plays in the earth system, and prioritize the urgent action needed to heal and protect the ocean at the ‘Earthscape’ level – the planetary scale at which processes to support life operate. The countries gathering at COP26 have unparalleled political capacity and leadership to make this happen. COP26 could be the turning point, but there must be commitment to united action for the ocean, as well as planning to meet those commitments, based on science-led solutions that address the interconnectivity of the ocean, climate, and biodiversity. Key ways in which the ocean both contributes to and acts as the major buffer for climate change are summarized, focusing on temperature, but not forgetting the role of storing carbon. It is noted with ‘high confidence’ that the ocean has stored 91% of the excess heat from global warming, with land, melting ice, and the atmosphere only taking up approximately 5, 3, and 1%, respectively. We also highlight the impact of the recent large release of heat from the ocean to the atmosphere during the 2015–2016 El Niño. We then present six science-based policy actions that form a recovery stimulus package for people, climate, nature, and the planet. Our proposals highlight what is needed to view, value, and treat the planet, including the ocean, for the benefit and future of all life.
Abstract.
Epstein G, Middelburg JJ, Hawkins JP, Norris CR, Roberts CM (2022). The impact of mobile demersal fishing on carbon storage in seabed sediments.
Global Change Biology,
28(9), 2875-2894.
Abstract:
The impact of mobile demersal fishing on carbon storage in seabed sediments
AbstractSubtidal marine sediments are one of the planet's primary carbon stores and strongly influence the oceanic sink for atmospheric CO2. By far the most widespread human activity occurring on the seabed is bottom trawling/dredging for fish and shellfish. A global first‐order estimate suggested mobile demersal fishing activities may cause 0.16–0.4 Gt of organic carbon (OC) to be remineralized annually from seabed sediment carbon stores (Sala et al. 2021). There are, however, many uncertainties in this calculation. Here, we discuss the potential drivers of change in seabed sediment OC stores due to mobile demersal fishing activities and conduct a literature review, synthesizing studies where this interaction has been directly investigated. Under certain environmental settings, we hypothesize that mobile demersal fishing would reduce OC in seabed stores due to lower production of flora and fauna, the loss of fine flocculent material, increased sediment resuspension, mixing and transport and increased oxygen exposure. Reductions would be offset to varying extents by reduced faunal bioturbation and community respiration, increased off‐shelf transport and increases in primary production from the resuspension of nutrients. Studies which directly investigated the impact of demersal fishing on OC stocks had mixed results. A finding of no significant effect was reported in 61% of 49 investigations; 29% reported lower OC due to fishing activities, with 10% reporting higher OC. In relation to remineralization rates within the seabed, four investigations reported that demersal fishing activities decreased remineralization, with three reporting higher remineralization rates. Patterns in the environmental and experimental characteristics between different outcomes were largely indistinct. More evidence is urgently needed to accurately quantify the impact of anthropogenic physical disturbance on seabed carbon in different environmental settings and to incorporate full evidence‐based carbon considerations into global seabed management.
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Duarte CM, Agusti S, Barbier E, Britten GL, Castilla JC, Gattuso J-P, Fulweiler RW, Hughes TP, Knowlton N, Lovelock CE, et al (2021). Author Correction: Rebuilding marine life. Nature, 593(7857), e1-e2.
Grorud-Colvert K, Sullivan-Stack J, Roberts C, Constant V, Horta E Costa B, Pike EP, Kingston N, Laffoley D, Sala E, Claudet J, et al (2021). The MPA Guide: a framework to achieve global goals for the ocean. Science, 373(6560).
Sumaila UR, Skerritt DJ, Schuhbauer A, Villasante S, Cisneros-Montemayor AM, Sinan H, Burnside D, Abdallah PR, Abe K, Addo KA, et al (2021). WTO must ban harmful fisheries subsidies.
Science,
374(6567).
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Roberts CM, O'Leary BC, Hawkins JP (2020). Climate change mitigation and nature conservation both require higher protected area targets.
Philosophical Transactions of the Royal Society B: Biological Sciences,
375(1794).
Abstract:
Climate change mitigation and nature conservation both require higher protected area targets
Nations of the world have, to date, pursued nature protection and climate change mitigation and adaptation policies separately. Both efforts have failed to achieve the scale of action needed to halt biodiversity loss or mitigate climate change.We argue that success can be achieved by aligning targets for biodiversity protection with the habitat protection and restoration necessary to bring down greenhouse gas concentrations and promote natural and societal adaptation to climate change. Success, however, will need much higher targets for environmental protection than the present 10% of sea and 17% of land. A new target of 30% of the sea given high levels of protection from exploitation and harm by 2030 is under consideration and similar targets are being discussed for terrestrial habitats. We make the case here that these higher targets, if achieved, would make the transition to a warmer world slower and less damaging for nature and people.
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Laffoley D, Baxter JM, Amon DJ, Currie DEJ, Downs CA, Hall-Spencer JM, Harden-Davies H, Page R, Reid CP, Roberts CM, et al (2020). Eight urgent, fundamental and simultaneous steps needed to restore ocean health, and the consequences for humanity and the planet of inaction or delay.
Aquatic Conservation: Marine and Freshwater Ecosystems,
30(1), 194-208.
Abstract:
Eight urgent, fundamental and simultaneous steps needed to restore ocean health, and the consequences for humanity and the planet of inaction or delay
The ocean crisis is urgent and central to human wellbeing and life on Earth; past and current activities are damaging the planet's main life support system for future generations. We are witnessing an increase in ocean heat, disturbance, acidification, bio-invasions and nutrients, and reducing oxygen levels. Several of these act like ratchets: once detrimental or negative changes have occurred, they may lock in place and may not be reversible, especially at gross ecological and ocean process scales. Each change may represent a loss to humanity of resources, ecosystem function, oxygen production and species. The longer we pursue unsuitable actions, the more we close the path to recovery and better ocean health and greater benefits for humanity in the future. We stand at a critical juncture and have identified eight priority issues that need to be addressed in unison to help avert a potential ecological disaster in the global ocean. They form a purposely ambitious agenda for global governance and are aimed at informing decision-makers at a high level. They should also be of interest to the general public. of all the themes, the highest priority is to rigorously address global warming and limit surface temperature rise to 1.5°C by 2100, as warming is the pre-eminent factor driving change in the ocean. The other themes are establishing a robust and comprehensive High Seas Treaty, enforcing existing standards for Marine Protected Areas and expanding their coverage, especially in terms of high levels of protection, adopting a precautionary pause on deep-sea mining, ending overfishing and destructive fishing practices, radically reducing marine pollution, putting in place a financing mechanism for ocean management and protection, and lastly, scaling up science/data gathering and facilitating data sharing. By implementing all eight measures in unison, as a coordinated strategy, we can build resilience to climate change, help sustain fisheries productivity, particularly for low-income countries dependent on fisheries, protect coasts (e.g. via soft-engineering/habitat-based approaches), promote mitigation (e.g. carbon storage) and enable improved adaptation to rapid global change.
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Stewart BD, Howarth LM, Wood H, Whiteside K, Carney W, Crimmins E, O'Leary BC, Hawkins JP, Roberts CM (2020). Marine Conservation Begins at Home: How a Local Community and Protection of a Small Bay Sent Waves of Change Around the UK and Beyond.
FRONTIERS IN MARINE SCIENCE,
7 Author URL.
O'Leary BC, Hoppit G, Townley A, Allen HL, McIntyre CJ, Roberts CM (2020). Options for managing human threats to high seas biodiversity. Ocean & Coastal Management, 187, 105110-105110.
Murray A, Garrud E, Ender I, Lee-Brooks K, Atkins R, Lynam R, Arnold K, Roberts C, Hawkins J, Stevens G, et al (2020). Protecting the million-dollar mantas; creating an evidencebased code of conduct for manta ray tourism interactions.
JOURNAL OF ECOTOURISM,
19(2), 132-147.
Author URL.
Duarte CM, Agusti S, Barbier E, Britten GL, Castilla JC, Gattuso J-P, Fulweiler RW, Hughes TP, Knowlton N, Lovelock CE, et al (2020). Rebuilding marine life. Nature, 580(7801), 39-51.
Burns P, Hawkins J, Roberts C (2020). Reconstructing the history of ocean wildlife around Ascension Island.
AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS,
30(6), 1220-1237.
Author URL.
Dyson F, Nelson A, Savage-Smith E, Pettifor A, Roberts C, Serageldin I, Ihekweazu C (2019). Books for our time: seven classics that speak to us now. Nature, 576(7787), 374-378.
O’Leary BC, Fieldhouse P, McClean CJ, Ford AES, Burns P, Hawkins JP, Roberts CM (2019). Evidence gaps and biodiversity threats facing the marine environment of the United Kingdom’s Overseas Territories.
Biodiversity and Conservation,
28(2), 363-383.
Abstract:
Evidence gaps and biodiversity threats facing the marine environment of the United Kingdom’s Overseas Territories
Understanding the evidence base and identifying threats to the marine environment is critical to ensure cost-effective management and to identify priorities for future research. The United Kingdom (UK) government is responsible for approximately 2% of the world’s oceans, most of which belongs to its 14 Overseas Territories (UKOTs). Containing biodiversity of global significance, and far in excess of the UK mainland’s domestic species, there has recently been a strong desire from many of the UKOTs, the UK Government, and NGOs to improve marine management in these places. Implementing evidence-based marine policy is, however, challenged by the disparate nature of scientific research in the UKOTs and knowledge gaps about the threats they face. Here, we address these issues by systematically searching for scientific literature which has examined UKOT marine biodiversity and by exploring publicly available spatial threat data. We find that UKOT marine biodiversity has received consistent, but largely low, levels of scientific interest, and there is considerable geographical and subject bias in research effort. of particular concern is the lack of research focus on management or threats to biodiversity. The extent and intensity of threats vary amongst and within the UKOTs but unsurprisingly, climate change associated threats affect them all and direct human stressors are more prevalent in those with higher human populations. To meet global goals for effective conservation and management, there is an urgent need for additional and continued investment in research and management in the Overseas Territories, particularly those that have been of lesser focus.
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Johnson DE, Rees SE, Diz D, Jones PJS, Roberts C, Froján CB (2019). Securing effective and equitable coverage of marine protected areas: the UK's progress towards achieving Convention on Biological Diversity commitments and lessons learned for the way forward. Aquatic Conservation Marine and Freshwater Ecosystems, 29(S2), 181-194.
Roberts C (2019). There were walls of fish, so many you could hardly see the corals. Biologist, 66(3), 12-17.
O'Leary BC, Ban NC, Fernandez M, Friedlander AM, García-Borboroglu P, Golbuu Y, Guidetti P, Harris JM, Hawkins JP, Langlois T, et al (2018). Addressing Criticisms of Large-Scale Marine Protected Areas.
BioScience,
68(5), 359-370.
Abstract:
Addressing Criticisms of Large-Scale Marine Protected Areas
Designated large-scale marine protected areas (LSMPAs, 100,000 or more square kilometers) constitute over two-thirds of the approximately 6.6% of the ocean and approximately 14.5% of the exclusive economic zones within marine protected areas. Although LSMPAs have received support among scientists and conservation bodies for wilderness protection, regional ecological connectivity, and improving resilience to climate change, there are also concerns. We identified 10 common criticisms of LSMPAs along three themes: (1) placement, governance, and management; (2) political expediency; and (3) social ecological value and cost. Through critical evaluation of scientific evidence, we discuss the value, achievements, challenges, and potential of LSMPAs in these arenas. We conclude that although some criticisms are valid and need addressing, none pertain exclusively to LSMPAs, and many involve challenges ubiquitous in management. We argue that LSMPAs are an important component of a diversified management portfolio that tempers potential losses, hedges against uncertainty, and enhances the probability of achieving sustainably managed oceans.
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Sala E, Lubchenco J, Grorud-Colvert K, Novelli C, Roberts C, Sumaila UR (2018). Assessing real progress towards effective ocean protection. Marine Policy, 91, 11-13.
Stevens GMW, Hawkins JP, Roberts CM (2018). Courtship and mating behaviour of manta rays Mobula alfredi and M. birostris in the Maldives.
Journal of Fish Biology,
93(2), 344-359.
Abstract:
Courtship and mating behaviour of manta rays Mobula alfredi and M. birostris in the Maldives
The aim of this 14 year study was to elucidate the entire courtship and mating behaviour of manta rays Mobula alfredi and M. birostris using behavioural observations, video and photographic records. From 2003 to 2016, over 11,000 surveys were undertaken at known manta ray aggregation sites in the Maldives to record any observed manta rays reproductive activity. From 47,591 photo-ID sightings, 4,247 individual M. alfredi were identified and 226 individual M. birostris from 229 photo-ID sightings, all recorded at 22 atolls across 265 different sites. Courtship activity was observed on 206 surveys at 30 different sites. A total of 229 courtship events were recorded, with 90% (n = 205) of them occurring at cleaning sites. The observed courtship activity was categorised into seven distinct stages which are described in detail: initiation, endurance, evasion, pre-copulatory positioning, copulation, post-copulatory holding and separation. Photographs provide the first scientific record of the entirety of manta rays courtship and mating. Both M. alfredi and M. birostris appear to engage in the same elaborate courtship rituals, exhibiting the same behaviours during all stages of the courtship and mating process.
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O'Leary BC, Roberts CM (2018). Ecological connectivity across ocean depths: Implications for protected area design. Global Ecology and Conservation, 15, e00431-e00431.
López-Angarita J, Tilley A, Hawkins JP, Pedraza C, Roberts CM (2018). Land use patterns and influences of protected areas on mangroves of the eastern tropical Pacific.
Biological Conservation,
227, 82-91.
Abstract:
Land use patterns and influences of protected areas on mangroves of the eastern tropical Pacific
Mangroves are one of the most productive ecosystems in the world, sustaining millions of coastal livelihoods. However, their area of occurrence has been greatly reduced over the last century. In this study, we identify potential drivers of land use and land cover change adjacent to mangroves on the Pacific shorelines of Colombia, Panama and Costa Rica. We also evaluate the effectiveness of protected areas at halting mangrove deforestation between 2000 and 2012. Across all countries, agriculture was the most dominant land use type adjacent to mangroves, inside and outside protected areas. Results show that a combined total of 564 ha were lost, representing an average loss rate of only 0.02% per year. 75% of the total mangrove loss occurred in locations outside protected areas, with only 138 ha cleared from inside protected areas. Results suggest current conservation policies for mangrove protection in the study countries are effective at reducing deforestation and set a positive example for regions where mangroves are in decline.
Abstract.
López-Angarita J, Tilley A, Díaz JM, Hawkins JP, Cagua EF, Roberts CM (2018). Winners and losers in area-based management of a small-scale fishery in the Colombian Pacific.
Frontiers in Marine Science,
5(FEB).
Abstract:
Winners and losers in area-based management of a small-scale fishery in the Colombian Pacific
The Pacific coast of Colombia has some of the most extensive mangrove forests in South America. As an isolated region and one of the country's poorest, coastal communities rely on fishing as a main source of animal protein and income. In an attempt to reverse declining trends of fisheries resources, in 2008, an Exclusive Zone of Artisanal Fishing closed to industrial fishing, was established by stakeholders in the Northern Chocó region. Here we present a case study to investigate the effects of this area-based management on fisheries productivity and catch composition. Fishery landings data from 2010 to 2013 are compared to those of a neighbouring region with no fisheries management. Catch per unit effort, mean weight landed, and number of landed individuals were calculated for mangrove and non-mangrove associated species by boat type and fishing gear. A set of mixed effects models were used to unpack the effects of multiple factors and their interactions on response variables. Results show that across fishing gears and time, mean catch per unit effort increased by 50% in the Exclusive Zone of Artisanal Fishing within 3 years. Fisheries here focused on offshore resources with 61% more fishing trips associated with motorised boats than in the unmanaged region, where fishing was predominantly in mangroves and close to the coast. This suggests that fisheries management may have played a role in reducing pressure on mangrove resources. However, area-based management may have also driven the displacement of fishing effort by excluding industrial trawlers, which then concentrated their activity in neighbouring areas.
Abstract.
Plumeridge AA, Roberts CM (2017). Conservation targets in marine protected area management suffer from shifting baseline syndrome: a case study on the Dogger Bank. Marine Pollution Bulletin, 116(1-2), 395-404.
Roberts CM, O'Leary BC, McCauley DJ, Cury PM, Duarte CM, Lubchenco J, Pauly D, Sáenz-Arroyo A, Sumaila UR, Wilson RW, et al (2017). Marine reserves can mitigate and promote adaptation to climate change.
Proc Natl Acad Sci U S A,
114(24), 6167-6175.
Abstract:
Marine reserves can mitigate and promote adaptation to climate change.
Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future.
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O'Leary BC, Winther-Janson M, Bainbridge JM, Aitken J, Hawkins JP, Roberts CM (2017). Reply to White et al.: Providing Perspective on Ocean Conservation Targets.
Conservation Letters,
10(3), 375-376.
Abstract:
Reply to White et al.: Providing Perspective on Ocean Conservation Targets
In O'Leary et al. (2016), we undertook a quantitative synthesis (rather than a true statistical meta-analysis) of research to consider how much of the sea should be protected to achieve various conservation and management goals. We aimed to provide perspective on the appropriateness of global marine protected area coverage targets, particularly the United Nations Sustainable Development Goal 14/Convention on Biological Diversity goals to protect >10% of the sea by 2020. White et al. (2017) question the methodology of our approach, and we offer the following response.
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O'Leary BC, Roberts CM (2017). The Structuring Role of Marine Life in Open Ocean Habitat: Importance to International Policy. Frontiers in Marine Science, 4
Howarth LM, Dubois P, Gratton P, Judge M, Christie B, Waggitt JJ, Hawkins JP, Roberts CM, Stewart BD (2017). Trade-offs in marine protection: Multispecies interactions within a community-led temperate marine reserve.
ICES Journal of Marine Science,
74(1), 263-276.
Abstract:
Trade-offs in marine protection: Multispecies interactions within a community-led temperate marine reserve
This study investigated the effects of a community-led temperate marine reserve in Lamlash Bay, Firth of Clyde, Scotland, on commercially important populations of European lobster (Homarus gammarus), brown crab (Cancer pagurus), and velvet swimming crabs (Necora puber). Potting surveys conducted over 4 years revealed significantly higher catch per unit effort (cpue 109% greater), weight per unit effort (wpue 189% greater), and carapace length (10-15 mm greater) in lobsters within the reserve compared with control sites. However, likely due to low levels of recruitment and increased fishing effort outside the reserve, lobster catches decreased in all areas during the final 2 years. Nevertheless, catch rates remained higher within the reserve across all years, suggesting the reserve buffered these wider declines. Additionally, lobster cpue and wpue declined with increasing distance from the boundaries of the marine reserve, a trend which tag-recapture data suggested were due to spillover. Catches of berried lobster were also twice as high within the reserve than outside, and the mean potential reproductive output per female was 22.1% greater. It was originally thought that higher densities of lobster within the reserve might lead to greater levels of aggression and physical damage. However, damage levels were solely related to body size, as large lobsters >110 mm had sustained over 218% more damage than smaller individuals. Interestingly, catches of adult lobsters were inversely correlated with those of juvenile lobsters, brown crabs, and velvet crabs, which may be evidence of competitive displacement and/or predation. Our findings provide evidence that temperate marine reserves can deliver fisheries and conservation benefits, and highlight the importance of investigating multispecies interactions, as the recovery of some species can have knock-on effects on others.
Abstract.
O'Leary BC, Winther-Janson M, Bainbridge JM, Aitken J, Hawkins JP, Roberts CM (2016). Effective Coverage Targets for Ocean Protection.
Conservation Letters,
9(6), 398-404.
Abstract:
Effective Coverage Targets for Ocean Protection
The UN's globally adopted Convention on Biological Diversity coverage target for marine protected areas (MPAs) is ≥10% by 2020. In 2014, the World Parks Congress recommended increasing this to ≥30%. We reviewed 144 studies to assess whether the UN target is adequate to achieve, maximize, or optimize six environmental and/or socioeconomic objectives. Results consistently indicate that protecting several tens-of-percent of the sea is required to meet goals (average 37%, median 35%, modal group 21–30%), greatly exceeding the 2.18% currently protected and the 10% target. The objectives we examined were met in 3% of studies with ≤10% MPA coverage, 44% with ≤30% coverage, and 81% with more than half the sea protected. The UN's 10% target appears insufficient to protect biodiversity, preserve ecosystem services, and achieve socioeconomic priorities. As MPA coverages generated from theoretical studies inherently depend on scenario(s) considered, our findings do not represent explicit recommendations but rather provide perspective on policy goals.
Abstract.
Bégin C, Schelten CK, Nugues MM, Hawkins J, Roberts C, Côté IM (2016). Effects of Protection and Sediment Stress on Coral Reefs in Saint Lucia.
PLoS One,
11(2).
Abstract:
Effects of Protection and Sediment Stress on Coral Reefs in Saint Lucia.
The extent to which Marine Protected Areas (MPAs) benefit corals is contentious. On one hand, MPAs could enhance coral growth and survival through increases in herbivory within their borders; on the other, they are unlikely to prevent disturbances, such as terrestrial runoff, that originate outside their boundaries. We examined the effect of spatial protection and terrestrial sediment on the benthic composition of coral reefs in Saint Lucia. In 2011 (10 to 16 years after MPAs were created), we resurveyed 21 reefs that had been surveyed in 2001 and analyzed current benthic assemblages as well as changes in benthic cover over that decade in relation to protection status, terrestrial sediment influence (measured as the proportion of terrigenous material in reef-associated sediment) and depth. The cover of all benthic biotic components has changed significantly over the decade, including a decline in coral and increase in macroalgae. Protection status was not a significant predictor of either current benthic composition or changes in composition, but current cover and change in cover of several components were related to terrigenous content of sediment deposited recently. Sites with a higher proportion of terrigenous sediment had lower current coral cover, higher macroalgal cover and greater coral declines. Our results suggest that terrestrial sediment is an important factor in the recent degradation of coral reefs in Saint Lucia and that the current MPA network should be complemented by measures to reduce runoff from land.
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Author URL.
López-Angarita J, Roberts CM, Tilley A, Hawkins JP, Cooke RG (2016). Mangroves and people: Lessons from a history of use and abuse in four Latin American countries.
Forest Ecology and Management,
368, 151-162.
Abstract:
Mangroves and people: Lessons from a history of use and abuse in four Latin American countries
From native pre-Columbian subsistence economies to the modern global economy, mangroves have played an important role providing goods and services to human societies for millennia. More than 90% of the world's mangroves are located in developing countries, where rates of destruction are increasing rapidly and on large scales. In order to design effective conservation strategies, it is critical to understand the natural dynamics and anthropogenic drivers of these coastal wetland habitats. We use retrospective techniques to reconstruct mangrove forest history in the Eastern Tropical Pacific. We examine available, present day estimates of mangrove area and evaluate the representation of mangroves in the protected area systems of Costa Rica, Panama, Colombia and Ecuador, evaluating existing policies regarding mangroves. Archaeozoological evidence shows that mangroves were exploited for many thousands of years by pre-Columbian societies. Post-conquest deforestation prevailed during the next 400 years. Since 1990, despite increasingly positive attitudes towards mangroves and their inclusion in protected areas and conservation policies, mangrove cover has continued to decline due to expanding human activities (agriculture, aquaculture, coastal development), even in the presence of laws prohibiting their removal. Here we provide an historical ecology baseline of mangroves in the Eastern Tropical Pacific, from which to view current trends and map future trajectories. Given the myriad negative consequences of mangrove loss recorded worldwide, and the strong ecological connectivity of the region, developing effective strategies for mangrove management at an appropriate scale will be paramount to protect coastal livelihoods and biodiversity.
Abstract.
Hawkins JP, O'Leary BC, Bassett N, Peters H, Rakowski S, Reeve G, Roberts CM (2016). Public awareness and attitudes towards marine protection in the United Kingdom.
Marine Pollution Bulletin,
111(1-2), 231-236.
Abstract:
Public awareness and attitudes towards marine protection in the United Kingdom
Public perception research evaluating awareness and attitudes towards marine protection is limited in the United Kingdom (UK) and worldwide. Given public opinion can help drive policy and affect its successful delivery we conducted nationwide surveys in 2005, 2010 and 2015 to assess public knowledge of UK (England, Scotland and Wales) sea ‘health’ and management. Respondents from all three surveys were relatively pessimistic about sea ‘health’, perceiving this as poor-fair and largely in decline. Enthusiasm for marine conservation was high with almost two-thirds of respondents in each survey wanting > 40% of UK seas highly protected from fishing and damaging activities. In 2015 there was considerable dissatisfaction with the rate of progress in Marine Conservation Zone designation and over three-quarters of respondents considered dredging and trawling to be inappropriate in protected areas, contrary to management. The UK government and devolved administrations need to better align future conservation and management with public expectations.
Abstract.
Peters H, O'Leary BC, Hawkins JP, Roberts CM (2016). The cone snails of Cape Verde: Marine endemism at a terrestrial scale.
Global Ecology and Conservation,
7, 201-213.
Abstract:
The cone snails of Cape Verde: Marine endemism at a terrestrial scale
Cape Verde in the Eastern Atlantic is typical of many island groups in supporting a wealth of endemic species both terrestrial and marine. Marine gastropod molluscs of the genus Conus, commonly known as cone snails, occur in coastal tropical waters throughout the globe, but in Cape Verde their endemism reaches its apogee with 53 out of 56 species occurring nowhere else, the majority of which are restricted to single islands and frequently to single bays. However, Cape Verde is rapidly moving to a tourism-based economy with a projected boom in infrastructure development often coincidental with the shallow-water habitat of many range-restricted Conus. The conservation assessment of Conus to standards of the International Union for the Conservation of Nature (IUCN) Red List of Endangered Species, found that 45.3% of 53 species assessed from Cape Verde are threatened or near-threatened with extinction compared to 7.4% of 579 species in the rest of the world. The only three Conus species globally assessed as Critically Endangered and on the cusp of extinction are all endemic to Cape Verde. Our analysis of Conus species distribution, together with spatial data of coastal protected areas and tourism development zones, identify important areas for future research and new marine protection. Our findings show that endemism with its associated risks for Conus in Cape Verde has worldwide parallels with many non-marine taxa, while our proposed strategy for Conus conservation extends beyond the confines of the country and this taxonomic group.
Abstract.
Howarth LM, Roberts CM, Hawkins JP, Steadman DJ, Beukers-Stewart BD (2015). Effects of ecosystem protection on scallop populations within a community-led temperate marine reserve.
Marine Biology,
162(4), 823-840.
Abstract:
Effects of ecosystem protection on scallop populations within a community-led temperate marine reserve
This study investigated the effects of a newly established, fully protected marine reserve on benthic habitats and two commercially valuable species of scallop in Lamlash Bay, Isle of Arran, United Kingdom. Annual dive surveys from 2010 to 2013 showed the abundance of juvenile scallops to be significantly greater within the marine reserve than outside. Generalised linear models revealed this trend to be significantly related to the greater presence of macroalgae and hydroids growing within the boundaries of the reserve. These results suggest that structurally complex habitats growing within the reserve have substantially increased spat settlement and/or survival. The density of adult king scallops declined threefold with increasing distance from the boundaries of the reserve, indicating possible evidence of spillover or reduced fishing effort directly outside and around the marine reserve. However, there was no difference in the mean density of adult scallops between the reserve and outside. Finally, the mean age, size, and reproductive and exploitable biomass of king scallops were all significantly greater within the reserve. In contrast to king scallops, the population dynamics of queen scallops (Aequipecten opercularis) fluctuated randomly over the survey period and showed little difference between the reserve and outside. Overall, this study is consistent with the hypothesis that marine reserves can encourage the recovery of seafloor habitats, which, in turn, can benefit populations of commercially exploited species, emphasising the importance of marine reserves in the ecosystem-based management of fisheries.
Abstract.
Thurstan RH, McClenachan L, Crowder LB, Drew JA, Kittinger JN, Levin PS, Roberts CM, Pandolfi JM (2015). Filling historical data gaps to foster solutions in marine conservation.
Ocean and Coastal Management,
115, 31-40.
Abstract:
Filling historical data gaps to foster solutions in marine conservation
Ecological data sets rarely extend back more than a few decades, limiting our understanding of environmental change and its drivers. Marine historical ecology has played a critical role in filling these data gaps by illuminating the magnitude and rate of ongoing changes in marine ecosystems. Yet despite a growing body of knowledge, historical insights are rarely explicitly incorporated in mainstream conservation and management efforts. Failing to consider historical change can have major implications for conservation, such as the ratcheting down of expectations of ecosystem quality over time, leading to less ambitious targets for recovery or restoration. We discuss several unconventional sources used by historical ecologists to fill data gaps - including menus, newspaper articles, cookbooks, museum collections, artwork, benthic sediment cores - and novel techniques for their analysis. We specify opportunities for the integration of historical data into conservation and management, and highlight the important role that these data can play in filling conservation data gaps and motivating conservation actions. As historical marine ecology research continues to grow as a multidisciplinary enterprise, great opportunities remain to foster direct linkages to conservation and improve the outlook for marine ecosystems.
Abstract.
Peters H, O'Leary BC, Hawkins JP, Roberts CM (2015). Identifying species at extinction risk using global models of anthropogenic impact.
Global Change Biology,
21(2), 618-628.
Abstract:
Identifying species at extinction risk using global models of anthropogenic impact
The International Union for Conservation of Nature Red List of Endangered Species employs a robust, standardized approach to assess extinction threat focussed on taxa approaching an end-point in population decline. Used alone, we argue this enforces a reactive approach to conservation. Species not assessed as threatened but which occur predominantly in areas with high levels of anthropogenic impact may require proactive conservation management to prevent loss. We matched distribution and bathymetric range data from the global Red List assessment of 632 species of marine cone snails with human impacts and projected ocean thermal stress and aragonite saturation (a proxy for ocean acidification). Our results show 67 species categorized as 'Least Concern' have 70% or more of their occupancy in places subject to high and very high levels of human impact with 18 highly restricted species (range
Abstract.
Howarth LM, Pickup SE, Evans LE, Cross TJ, Hawkins JP, Roberts CM, Stewart BD (2015). Sessile and mobile components of a benthic ecosystem display mixed trends within a temperate marine reserve.
Marine Environmental Research,
107, 8-23.
Abstract:
Sessile and mobile components of a benthic ecosystem display mixed trends within a temperate marine reserve
Despite recent efforts to increase the global coverage of marine protected areas (MPAs), studies investigating the effectiveness of marine protected areas within temperate waters remain scarce. Furthermore, out of the few studies published on MPAs in temperate waters, the majority focus on specific ecological or fishery components rather than investigating the ecosystem as a whole. This study therefore investigated the dynamics of both benthic communities and fish populations within a recently established, fully protected marine reserve in Lamlash Bay, Isle of Arran, United Kingdom, over a four year period. A combination of photo and diver surveys revealed live maerl (Phymatolithon calcareum), macroalgae, sponges, hydroids, feather stars and eyelash worms (Myxicola infundibulum) to be significantly more abundant within the marine reserve than on surrounding fishing grounds. Likewise, the overall composition of epifaunal communities in and outside the reserve was significantly different. Both results are consistent with the hypothesis that protecting areas from fishing can encourage seafloor habitats to recover. In addition, the greater abundance of complex habitats within the reserve appeared to providing nursery habitat for juvenile cod (Gadus morhua) and scallops (Pecten maximus and Aequipecten opercularis). In contrast, there was little difference in the abundance of mobile benthic fauna, such as crabs and starfish, between the reserve and outside. Similarly, the use of baited underwater video cameras revealed no difference in the abundance and size of fish between the reserve and outside. Limited recovery of these ecosystem components may be due to the relatively small size (2.67 km2) and young age of the reserve (
Abstract.
Richards K, O'Leary BC, Roberts CM, Ormond R, Gore M, Hawkins JP (2015). Sharks and people: Insight into the global practices of tourism operators and their attitudes to Shark behaviour.
Marine Pollution Bulletin,
91(1), 200-210.
Abstract:
Sharks and people: Insight into the global practices of tourism operators and their attitudes to Shark behaviour
Shark tourism is a popular but controversial activity. We obtained insights into this industry via a global e-mailed questionnaire completed by 45 diving/snorkelling operators who advertised shark experiences (shark operators) and 49 who did not (non-shark operators). 42% of shark operators used an attractant to lure sharks and 93% stated they had a formal code of conduct which 86% enforced "very strictly". While sharks were reported to normally ignore people, 9 operators had experienced troublesome behaviour from them. Whilst our research corroborates previous studies indicating minimal risk to humans from most shark encounters, a precautionary approach to provisioning is required to avoid potential ecological and societal effects of shark tourism. Codes of conduct should always stipulate acceptable diver behaviour and appropriate diver numbers and shark operators should have a moral responsibility to educate their customers about the need for shark conservation.
Abstract.
Sumaila UR, Lam VWY, Miller DD, Teh L, Watson RA, Zeller D, Cheung WWL, Côté IM, Rogers AD, Roberts C, et al (2015). Winners and losers in a world where the high seas is closed to fishing. Scientific Reports, 5(1).
Barrett JH, Locker AM, Roberts CM (2015). ‘Dark Age Economics’ revisited: the English fish bone evidence AD 600-1600. Antiquity, 78(301), 618-636.
Thurstan RH, Hawkins JP, Roberts CM (2014). Origins of the bottom trawling controversy in the British Isles: 19th century witness testimonies reveal evidence of early fishery declines.
Fish and Fisheries,
15(3), 506-522.
Abstract:
Origins of the bottom trawling controversy in the British Isles: 19th century witness testimonies reveal evidence of early fishery declines
Bottom trawling (nets towed along the seabed) spread around the British Isles from the 1820s, yet the collection of national fisheries statistics did not begin until 1886. Consequently, analysis of the impacts of trawling on fish stocks and habitats during this early period is difficult, yet without this information, we risk underestimating the extent of changes that have occurred as a result of trawling activities. We examined witness testimonies recorded during two Royal Commissions of Enquiry (1863-66 and 1883-85). These enquiries interviewed hundreds of fishers about the early effects of sail trawling and the changes they were witnessing to fish stocks, habitats and fishing practises during this time. We converted all quantitative statements of perceived change in fish stocks and fishing practices to relative change. Witnesses from the north-east of England interviewed during 1863 revealed an average perceived decline in whitefish of 64% during their careers, which many blamed upon trawling. Between 1867 and 1892, trawl-landing records from the same location suggest that this trajectory continued, with fish availability declining by 66% during the period. Fishers adapted to these declines by increasing distances travelled to fishing grounds and increasing gear size and quantity. However, inshore declines continued and by the early 1880s even trawl owners were calling for closures of territorial waters to trawling in order to protect fish nursery and spawning grounds. Until now, these testimonies have been largely forgotten, yet they reveal that alterations to near-shore habitats as a result of trawling began long before official data collection was initiated. © 2013 John Wiley & Sons Ltd.
Abstract.
Roberts C, Finkbeiner A, Comfort N, Farmelo G, Gong L, Draaisma D, Catley-Carlson M, Whiteman G, Abdulla S, Baker J, et al (2014). Summer books. Nature, 511(7508), 152-154.
Pimm SL, Jenkins CN, Abell R, Brooks TM, Gittleman JL, Joppa LN, Raven PH, Roberts CM, Sexton JO (2014). The biodiversity of species and their rates of extinction, distribution, and protection.
Science,
344(6187).
Abstract:
The biodiversity of species and their rates of extinction, distribution, and protection
. Background
. A principal function of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is to “perform regular and timely assessments of knowledge on biodiversity.” in December 2013, its second plenary session approved a program to begin a global assessment in 2015. The Convention on Biological Diversity (CBD) and five other biodiversity-related conventions have adopted IPBES as their science-policy interface, so these assessments will be important in evaluating progress toward the CBD’s Aichi Targets of the Strategic Plan for Biodiversity 2011–2020. As a contribution toward such assessment, we review the biodiversity of eukaryote species and their extinction rates, distributions, and protection. We document what we know, how it likely differs from what we do not, and how these differences affect biodiversity statistics. Interestingly, several targets explicitly mention “known species”—a strong, if implicit, statement of incomplete knowledge. We start by asking how many species are known and how many remain undescribed. We then consider by how much human actions inflate extinction rates. Much depends on where species are, because different biomes contain different numbers of species of different susceptibilities. Biomes also suffer different levels of damage and have unequal levels of protection. How extinction rates will change depends on how and where threats expand and whether greater protection counters them.
.
.
. Advances
. Recent studies have clarified where the most vulnerable species live, where and how humanity changes the planet, and how this drives extinctions. These data are increasingly accessible, bringing greater transparency to science and governance. Taxonomic catalogs of plants, terrestrial vertebrates, freshwater fish, and some marine taxa are sufficient to assess their status and the limitations of our knowledge. Most species are undescribed, however. The species we know best have large geographical ranges and are often common within them. Most known species have small ranges, however, and such species are typically newer discoveries. The numbers of known species with very small ranges are increasing quickly, even in well-known taxa. They are geographically concentrated and are disproportionately likely to be threatened or already extinct. We expect unknown species to share these characteristics. Current rates of extinction are about 1000 times the background rate of extinction. These are higher than previously estimated and likely still underestimated. Future rates will depend on many factors and are poised to increase. Finally, although there has been rapid progress in developing protected areas, such efforts are not ecologically representative, nor do they optimally protect biodiversity.
.
.
. Outlook
.
. Progress on assessing biodiversity will emerge from continued expansion of the many recently created online databases, combining them with new global data sources on changing land and ocean use and with increasingly crowdsourced data on species’ distributions. Examples of practical conservation that follow from using combined data in Colombia and Brazil can be found at
. www.savingspecies.org
. and
. www.youtube.com/watch?v=R3zjeJW2NVk
.
.
.
Abstract.
Singleton RL, Roberts CM (2014). The contribution of very large marine protected areas to marine conservation: Giant leaps or smoke and mirrors?.
Marine Pollution Bulletin,
87(1), 7-10.
Abstract:
The contribution of very large marine protected areas to marine conservation: Giant leaps or smoke and mirrors?
In recent years, marine protected areas have been "super-sized". At first glance, this seems a gift to marine conservation. Yet, the new wave of very large marine protected areas ("VLMPAs") have faced criticism from the scientific community. In this article we examine the merits and the criticisms of VLMPAS, and consider whether they provide a much-needed boost to marine conservation, or are simply too good to be true.
Abstract.
Thurstan RH, Roberts CM (2014). The past and future of fish consumption: can supplies meet healthy eating recommendations?.
Marine Pollution Bulletin,
89(1-2), 5-11.
Abstract:
The past and future of fish consumption: can supplies meet healthy eating recommendations?
In many developed countries fish and shellfish are increasingly promoted as healthy alternatives to other animal protein. We analysed how much fish was available to UK and global populations after accounting for processing losses, and compared this to recommended levels of fish consumption. In 2012, UK domestic fish landings per capita fell 81% below the recommended intake, although declines were masked by increased imports and aquaculture from the 1970s onwards. Global wild fish supply per capita declined by 32% from its peak in 1970. However, overall fish supplies per capita increased by 10% over the same period due to rapidly expanding aquaculture production. Whilst aquaculture has so far prevented a downturn in global fish supplies, many developed nations continue to aspire to consume more fish than they produce. Until demand is balanced with sustainable methods of production governments should consider carefully the social and environmental implications of greater fish consumption.
Abstract.
Howarth LM, Roberts CM, Thurstan RH, Stewart BD (2014). The unintended consequences of simplifying the sea: Making the case for complexity.
Fish and Fisheries,
15(4), 690-711.
Abstract:
The unintended consequences of simplifying the sea: Making the case for complexity
Many over-exploited marine ecosystems worldwide have lost their natural populations of large predatory finfish and have become dominated by crustaceans and other invertebrates. Controversially, some of these simplified ecosystems have gone on to support highly successful invertebrate fisheries capable of generating more economic value than the fisheries they replaced. Such systems have been compared with those created by modern agriculture on land, in that existing ecosystems have been converted into those that maximize the production of target species. Here, we draw on a number of concepts and case-studies to argue that this is highly risky. In many cases, the loss of large finfish has triggered dramatic ecosystem shifts to states that are both ecologically and economically undesirable, and difficult and expensive to reverse. In addition, we find that those stocks left remaining are unusually prone to collapse from disease, invasion, eutrophication and climate change. We therefore conclude that the transition from multispecies fisheries to simplified invertebrate fisheries is causing a global decline in biodiversity and is threatening global food security, rather than promoting it.
Abstract.
Peters H, O'Leary BC, Hawkins JP, Carpenter KE, Roberts CM (2013). Conus: First comprehensive conservation red list assessment of a marine gastropod mollusc genus.
PLoS ONE,
8(12).
Abstract:
Conus: First comprehensive conservation red list assessment of a marine gastropod mollusc genus
Marine molluscs represent an estimated 23% of all extant marine taxa, but research into their conservation status has so far failed to reflect this importance, with minimal inclusion on the authoritative Red List of the International Union for the Conservation of Nature (IUCN). We assessed the status of all 632 valid species of the tropical marine gastropod mollusc, Conus (cone snails), using Red List standards and procedures to lay the groundwork for future decadal monitoring, one of the first fully comprehensive global assessments of a marine taxon. Three-quarters (75.6%) of species were not currently considered at risk of extinction owing to their wide distribution and perceived abundance. However, 6.5% were considered threatened with extinction with a further 4.1% near threatened. Data deficiency prevented 13.8% of species from being categorised although they also possess characteristics that signal concern. Where hotspots of endemism occur, most notably in the Eastern Atlantic, 42.9% of the 98 species from that biogeographical region were classified as threatened or near threatened with extinction. All 14 species included in the highest categories of Critically Endangered and Endangered are endemic to either Cape Verde or Senegal, with each of the three Critically Endangered species restricted to single islands in Cape Verde. Threats to all these species are driven by habitat loss and anthropogenic disturbance, in particular from urban pollution, tourism and coastal development. Our findings show that levels of extinction risk to which cone snails are exposed are of a similar magnitude to those seen in many fully assessed terrestrial taxa. The widely held view that marine species are less at risk is not upheld. © 2013 Peters et al.
Abstract.
Roberts C (2013). Nature writing: Cetacean subtleties. Nature, 498(7452).
Thurstan RH, Hawkins JP, Raby L, Roberts CM (2013). Oyster (Ostrea edulis) extirpation and ecosystem transformation in the Firth of Forth, Scotland.
Journal for Nature Conservation,
21(5), 253-261.
Abstract:
Oyster (Ostrea edulis) extirpation and ecosystem transformation in the Firth of Forth, Scotland
Marine inshore communities, including biogenic habitats have undergone dramatic changes as a result of exploitation, pollution, land-use changes and introduced species. The Firth of Forth on the east coast of Scotland was once home to the most important oyster (Ostrea edulis Linnaeus, 1758) beds in Scotland. 19th and early 20th century fisheries scientists documented the degradation and loss of these beds, yet transformation of the wider benthic community has been little studied. We undertook archival searches, ecological surveys and shell community analysis using radioisotope dated sediment cores to investigate the history of decline of Forth oyster beds over the last 200 years and the changes to its wider biological communities. Quadrat analysis of the present day benthos reveal that soft-sediment communities dominate the Firth of Forth, with little remaining evidence of past oyster beds in places where abundant shell remains were picked up by a survey undertaken in 1895. Queen scallops (Aequipecten opercularis Linnaeus, 1758) and horse mussels (Modiolus modiolus Linnaeus, 1758) were once common within the Forth but have also markedly decreased compared to the earlier survey. Ouranalyses of shell remains suggest that overall mollusc biomass and species richness declined throughout the 19th century and early 20th century, suggesting broader-scale community change as human impacts increased and as habitats degraded. Inshore communities in the Firth of Forth today are less productive and less diverse compared to past states, with evidence suggesting that most of the damage was done by early bottom trawling and dredging activities. Given the pervasive nature of intensive trawling over the past 150 years, the kind of degradation we document for the Firth of Forth is likely to be commonplace within UK inshore communities. © 2013 Elsevier GmbH.
Abstract.
Thurstan RH, Hawkins JP, Neves L, Roberts CM (2012). Are marine reserves and non-consumptive activities compatible? a global analysis of marine reserve regulations.
Marine Policy,
36(5), 1096-1104.
Abstract:
Are marine reserves and non-consumptive activities compatible? a global analysis of marine reserve regulations
Marine reserves are places where wildlife and habitats are protected from extractive and depositional uses of the sea. Although considered to be the pinnacle in marine conservation, many permit non-consumptive activities with little or no regulation. This paper examines the potential impacts of 16 non-consumptive activities including scuba diving, sailing, scientific research and motor boating, and how they might compromise the conservation objectives of marine reserves. Examination of 91 marine reserves from 36 countries found little agreement or consistency in what non-consumptive activities are permitted in marine reserves and how they are regulated. The two most common activities allowed without regulation were swimming (mentioned in 80% of marine reserves and allowed in 63% of these) and kayaking (mentioned in 85%, allowed in 53%). Scuba diving was mentioned in 91% and allowed without regulation in 41%. A risk score for the likely level of threat to wildlife and/or habitats that each activity could produce was then assigned based on effects reported in the literature. The risk analysis suggests that motor boating and activities which include or require it have a high potential to negatively impact wildlife and habitats if inadequately managed. Hence protection against extractive or depositional activities alone is insufficient to secure the high standard of protection usually assumed in marine reserves. For this to be achieved activities typically considered as benign must receive appropriate management, especially with increasing recreational use. © 2012 Elsevier Ltd.
Abstract.
Veitch L, Dulvy NK, Koldewey H, Lieberman S, Pauly D, Roberts CM, Rogers AD, Baillie JEM (2012). Avoiding Empty Ocean Commitments at Rio+20. Science, 336(6087), 1383-1385.
Fox HE, Mascia MB, Basurto X, Costa A, Glew L, Heinemann D, Karrer LB, Lester SE, Lombana AV, Pomeroy RS, et al (2012). Reexamining the science of marine protected areas: Linking knowledge to action.
Conservation Letters,
5(1), 1-10.
Abstract:
Reexamining the science of marine protected areas: Linking knowledge to action
Marine protected areas (MPAs) are often implemented to conserve or restore species, fisheries, habitats, ecosystems, and ecological functions and services; buffer against the ecological effects of climate change; and alleviate poverty in coastal communities. Scientific research provides valuable insights into the social and ecological impacts of MPAs, as well as the factors that shape these impacts, providing useful guidance or "rules of thumb" for science-based MPA policy. Both ecological and social factors foster effective MPAs, including substantial coverage of representative habitats and oceanographic conditions; diverse size and spacing; protection of habitat bottlenecks; participatory decisionmaking arrangements; bounded and contextually appropriate resource use rights; active and accountable monitoring and enforcement systems; and accessible conflict resolution mechanisms. For MPAs to realize their full potential as a tool for ocean governance, further advances in policy-relevant MPA science are required. These research frontiers include MPA impacts on nontarget and wide-ranging species and habitats; impacts beyond MPA boundaries, on ecosystem services, and on resource-dependent human populations, as well as potential scale mismatches of ecosystem service flows. Explicitly treating MPAs as "policy experiments" and employing the tools of impact evaluation holds particular promise as a way for policy-relevant science to inform and advance science-based MPA policy. © 2011 Wiley Periodicals, Inc.
Abstract.
O'Leary BC, Smart JCR, Neale FC, Hawkins JP, Newman S, Milman AC, Datta S, Roberts CM (2012). Response to Cook et al. comment on " Fisheries Mismanagement". Marine Pollution Bulletin, 64(10), 2267-2271.
Hastings J, Thomas S, Burgener V, Gjerde K, Laffoley D, Salm R, McCook L, Pet-Soede L, Eichbaum WM, Bottema M, et al (2012). Safeguarding the blue planet: Six strategies for accelerating ocean protection.
Parks,
18(1), 9-22.
Abstract:
Safeguarding the blue planet: Six strategies for accelerating ocean protection
The oceans are facing greater pressures now than at any other time in human history. Marine protected areas (MPAs), nested within a wider approach of ecosystem-based management, have consistently emerged as one of the most important tools in halting the oceans’ decline and promoting their recovery. The Convention on Biological Diversity (CBD) Aichi Target 11 calls for at least 10 per cent of coastal and marine areas to be conserved through effectively and equitably managed, ecologically representative and well connected systems of protected areas by 2020; unfortunately, most of the Parties are not on track to meet this commitment. To contribute to this effort, this paper details six strategies that can accelerate MPA establishment and create resilient MPA management models around the world. These strategies (build public-private partnerships to change how MPAs are designed and financed; strengthen links between MPAs, local communities and livelihood needs; manage MPAs to enhance carbon stocks and address climate change; act on high seas conservation and initiate MPAs immediately; reframe thinking about the benefits of MPAs; and use technology to connect people with the oceans) can help ensure that the oceans are protected, well managed, and provide livelihood benefits for humanity far into the future.
Abstract.
O'Leary BC, Brown RL, Johnson DE, von Nordheim H, Ardron J, Packeiser T, Roberts CM (2012). The first network of marine protected areas (MPAs) in the high seas: the process, the challenges and where next. Marine Policy, 36(3), 598-605.
Grüss A, Kaplan DM, Guénette S, Roberts CM, Botsford LW (2011). Consequences of adult and juvenile movement for marine protected areas.
Biological Conservation,
144(2), 692-702.
Abstract:
Consequences of adult and juvenile movement for marine protected areas
Adult and juvenile mobility has a considerable influence on the functioning of marine protected areas. It is recognized that adult and juvenile movement reduces the core benefits of protected areas, namely protecting the full age-structure of marine populations, while at the same time perhaps improving fisheries yield over the no-reserve situation through export of individuals from protected areas. Nevertheless, the study of the consequences of movement on protected area functioning is unbalanced. Significant attention has been paid to the influence of certain movement patterns, such as diffusive movement and home ranges, while the impacts of others, such as density-dependent movements and ontogenetic migrations, have been relatively ignored. Here we review the diversity of density-independent and density-dependent movement patterns, as well as what is currently known about their consequences for the conservation and fisheries effects of marine protected areas. We highlight a number of 'partially addressed' issues in marine protected area research, such as the effects of reserves targeting specific life phases, and a number of essentially unstudied issues, such as density-dependent movements, nomadism, ontogenetic migrations, behavioral polymorphism and 'dynamic' reserves that adjust location as a realtime response to habitat changes. Assessing these issues will be essential to creating effective marine protected area networks for mobile species and accurately assessing reserve impacts on these species. © 2010 Elsevier Ltd.
Abstract.
O'Leary BC, Smart JCR, Neale FC, Hawkins JP, Newman S, Milman AC, Roberts CM (2011). Fisheries mismanagement.
Marine Pollution Bulletin,
62(12), 2642-2648.
Abstract:
Fisheries mismanagement
We analysed the extent to which European politicians have adhered to scientific recommendations on annual total allowable catches (TACs) from 1987 to 2011, covering most of the period of the Common Fisheries Policy (CFP). For the 11 stocks examined, TACs were set higher than scientific recommendations in 68% of decisions. Politically-adjusted TACs averaged 33% above scientifically recommended levels. There was no evidence that the 2002 reform of the CFP improved decision-making, as was claimed at the time. We modelled the effects of such politically-driven decision-making on stock sustainability. Our results suggest that political adjustment of scientific recommendations dramatically increases the probability of a stock collapsing within 40. years. In 2012 European fisheries policy will undergo a once-a-decade reform. Ten years ago radical reforms were promised but the changes failed to improve sustainability. It is likely that the 2012 reform will be similarly ineffective unless decision-making is changed so that catch allocations are based on science rather than politics. © 2011 Elsevier Ltd.
Abstract.
O'Leary BC, Roberts C (2011). Fishery reform: ban political haggling. Nature, 475(7357), 454-454.
Barrett JH, Orton D, Johnstone C, Harland J, Van Neer W, Ervynck A, Roberts C, Locker A, Amundsen C, Enghoff IB, et al (2011). Interpreting the expansion of sea fishing in medieval Europe using stable isotope analysis of archaeological cod bones. Journal of Archaeological Science, 38(7), 1516-1524.
Roberts CM, Quinn N, Tucker JW, Woodward PN (2011). Introduction of Hatchery‐Reared Nassau Grouper to a Coral Reef Environment. North American Journal of Fisheries Management, 15(1), 159-164.
Thurstan RH, Roberts CM (2010). Ecological meltdown in the firth of clyde, Scotland: Two centuries of change in a coastal marine ecosystem.
PLoS ONE,
5(7).
Abstract:
Ecological meltdown in the firth of clyde, Scotland: Two centuries of change in a coastal marine ecosystem
Background: the Firth of Clyde is a large inlet of the sea that extends over 100 km into Scotland's west coast. Methods: We compiled detailed fisheries landings data for this area and combined them with historical accounts to build a picture of change due to fishing activity over the last 200 years. Findings: in the early 19th century, prior to the onset of industrial fishing, the Firth of Clyde supported diverse and productive fisheries for species such as herring (Clupea harengus, Clupeidae), cod (Gadus morhua, Gadidae), haddock (Melanogrammus aeglefinus, Gadidae), turbot (Psetta maxima, Scophthalmidae) and flounder (Platichthys flesus, Pleuronectidae). The 19th century saw increased demand for fish, which encouraged more indiscriminate methods of fishing such as bottom trawling. During the 1880s, fish landings began to decline, and upon the recommendation of local fishers and scientists, the Firth of Clyde was closed to large trawling vessels in 1889. This closure remained in place until 1962 when bottom trawling for Norway lobster (Nephrops norvegicus, Nephropidae) was approved in areas more than three nautical miles from the coast. During the 1960s and 1970s, landings of bottomfish increased as trawling intensified. The trawl closure within three nautical miles of the coast was repealed in 1984 under pressure from the industry. Thereafter, bottomfish landings went into terminal decline, with all species collapsing to zero or near zero landings by the early 21st century. Herring fisheries collapsed in the 1970s as more efficient mid-water trawls and fish finders were introduced, while a fishery for mid-water saithe (Pollachius virens, Gadidae) underwent a boom and bust shortly after discovery in the late 1960s. The only commercial fisheries that remain today are for Nephrops and scallops (Pecten maximus, Pectinidae). Significance: the Firth of Clyde is a marine ecosystem nearing the endpoint of overfishing, a time when no species remain that are capable of sustaining commercial catches. The evidence suggests that trawl closures helped maintain productive fisheries through the mid-20th century, and their reopening precipitated collapse of bottomfish stocks. We argue that continued intensive bottom trawling for Nephrops with fine mesh nets will prevent the recovery of other species. This once diverse and highly productive environment will only be restored if trawl closures or other protected areas are re-introduced. The Firth of Clyde represents at a small scale a process that is occurring ocean-wide today, and its experience serves as a warning to others. © 2010 Thurstan, Roberts.
Abstract.
Thurstan RH, Brockington S, Roberts CM (2010). The effects of 118 years of industrial fishing on UK bottom trawl fisheries.
Nature Communications,
1(2).
Abstract:
The effects of 118 years of industrial fishing on UK bottom trawl fisheries
In 2009, the European Commission estimated that 88% of monitored marine fish stocks were overfished, on the basis of data that go back 20 to 40 years and depending on the species investigated. However, commercial sea fishing goes back centuries, calling into question the validity of management conclusions drawn from recent data. We compiled statistics of annual demersal fish landings from bottom trawl catches landing in England and Wales dating back to 1889, using previously neglected UK Government data. We then corrected the figures for increases in fishing power over time and a recent shift in the proportion of fish landed abroad to estimate the change in landings per unit of fishing power (LPUP), a measure of the commercial productivity of fisheries. LPUP reduced by 94% - 17-fold - over the past 118 years. This implies an extraordinary decline in the availability of bottom-living fish and a profound reorganization of seabed ecosystems since the nineteenth century industrialization of fishing.
Abstract.
Thurstan RH, Brockington S, Roberts CM (2010). The effects of 118 years of industrial fishing on UK bottom trawl fisheries.
Nature communications,
1Abstract:
The effects of 118 years of industrial fishing on UK bottom trawl fisheries.
In 2009, the European Commission estimated that 88% of monitored marine fish stocks were overfished, on the basis of data that go back 20 to 40 years and depending on the species investigated. However, commercial sea fishing goes back centuries, calling into question the validity of management conclusions drawn from recent data. We compiled statistics of annual demersal fish landings from bottom trawl catches landing in England and Wales dating back to 1889, using previously neglected UK Government data. We then corrected the figures for increases in fishing power over time and a recent shift in the proportion of fish landed abroad to estimate the change in landings per unit of fishing power (LPUP), a measure of the commercial productivity of fisheries. LPUP reduced by 94%-17-fold--over the past 118 years. This implies an extraordinary decline in the availability of bottom-living fish and a profound reorganization of seabed ecosystems since the nineteenth century industrialization of fishing.
Abstract.
Roberts CM (2009). Effects of Fishing on the Ecosystem Structure of Coral Reefs. Conservation Biology, 9(5), 988-995.
Sáenz‐Arroyo A, Roberts CM (2008). Consilience in fisheries science. Fish and Fisheries, 9(3), 316-327.
Barrett J, Johnstone C, Harland J, Van Neer W, Ervynck A, Makowiecki D, Heinrich D, Hufthammer AK, Enghoff IB, Amundsen C, et al (2008). Detecting the medieval cod trade: a new method and first results. Journal of Archaeological Science, 35(4), 850-861.
Gravestock P, Roberts CM, Bailey A (2008). The income requirements of marine protected areas. Ocean & Coastal Management, 51(3), 272-283.
Graham RT, Roberts CM (2007). Assessing the size, growth rate and structure of a seasonal population of whale sharks (Rhincodon typus Smith 1828) using conventional tagging and photo identification. Fisheries Research, 84(1), 71-80.
Mallela J, Roberts C, Harrod C, Goldspink CR (2007). Distributional patterns and community structure of Caribbean coral reef fishes within a river-impacted bay.
Journal of Fish Biology,
70(2), 523-537.
Abstract:
Distributional patterns and community structure of Caribbean coral reef fishes within a river-impacted bay
This study examined how riverine inputs, in particular sediment, influenced the community structure and trophic composition of reef fishes within Rio Bueno, north Jamaica. Due to river discharge a distinct gradient of riverine inputs existed across the study sites. Results suggested that riverine inputs (or a factor associated with them) had a structuring effect on fish community structure. Whilst fish communities at all sites were dominated by small individuals (
Abstract.
Hawkins JP, Roberts CM, Gell FR, Dytham C (2007). Effects of trap fishing on reef fish communities.
Aquatic Conservation: Marine and Freshwater Ecosystems,
17(2), 111-132.
Abstract:
Effects of trap fishing on reef fish communities
1. Trap fishing is widespread on coral reefs but the sustainability of this practice is causing concern because it is efficient and unselective. The effects of trap fishing were investigated by comparing fish assemblages among six Caribbean islands subject to different trapping pressures. These ranged from none in Bonaire and Saba increasing through Puerto Rico, St Lucia, Dominica and Jamaica respectively. 2. Fish were censused at depths of 5 m and 15 m on fore-reef slopes by counting the numbers within replicate 10 m diameter areas for 15 min. Between 64 and 1375 counts were made in each country. 3. In St Lucia and Jamaica abundance of fish censused on the reef was compared to representation in traps which were visually sampled underwater in the area of fish counts. Twenty-three traps were sampled in Jamaica and 75 in St Lucia. For some comparisons between these islands, St Lucian sampling effort was reduced to that of Jamaica (23 traps and 112 counts) by randomly sub-sampling 10 times. 4. Traps contained 54 different species in St Lucia and 22 in Jamaica, while there were 90 and 57 respectively in counts. After reducing St Lucian sampling effort to Jamaican levels, an average of 35 species were found in traps and 70 seen in counts. of these, 76% in St Lucia and 73% in Jamaica were relatively more abundant in traps than they were on the reef. 5. Species were considered to be highly susceptible to trapping if the ratio of their abundance in traps compared to that on the reef exceeded 3:1. Trapping pressure was approximately three and a half times greater in Jamaica than St Lucia. After equalizing sampling effort, there was an average of 16 highly trappable species in St Lucia compared to 13 in Jamaica. Species did not always appear highly trappable in both countries. Eleven of St Lucia's highly trappable species were absent from Jamaica (falling to 8.5 on average after equalizing sampling effort), but none vice versa, suggesting that trapping may have contributed to their absence or rarity on Jamaican reefs. 6. The Tetraodontiformes, which include many non-target species, were particularly susceptible to trapping in both countries. Their abundance in the six islands censused was inversely related to trap fishing pressure, as was that of two other non-target families, butterflyfish (Chaetodontidae) and angelfish (Pomacanthidae). 7. To determine whether fish that are common in traps in St Lucia are reaching sexual maturity before capture, size frequency data for 23 species from a sample of trap catches were gathered and examined for their state of maturity. In seven species, more than a third of 705 trapped fish were immature, indicating that trap fishing causes growth over-fishing (premature removal of fish), and calling into question the sustainability of yields for these species. 8. In conclusion, at the intensities seen in this study, trap fisheries cause serious over-fishing, reduce biodiversity, and alter ecosystem structure. While commonly perceived as low impact, coral reef trap fisheries in the Caribbean and further afield, need tighter regulation and control. Copyright © 2006 John Wiley & Sons, Ltd.
Abstract.
Mangi SC, Roberts CM (2007). Factors influencing fish catch levels on Kenya's coral reefs. Fisheries Management and Ecology, 14(4), 245-253.
Roberts C (2007). Faith, evolution, and the burden of proof [2]. Fisheries, 32(2).
Mangi SC, Roberts CM, Rodwell LD (2007). Financial Comparisons of Fishing Gear Used in Kenya's Coral Reef Lagoons. Ambio, 36(8), 671-676.
Graham RT, Carcamo R, Rhodes KL, Roberts CM, Requena N (2007). Historical and contemporary evidence of a mutton snapper (Lutjanus analis Cuvier, 1828) spawning aggregation fishery in decline. Coral Reefs, 27(2), 311-319.
Mangi SC, Roberts CM, Rodwell LD (2007). Reef fisheries management in Kenya: Preliminary approach using the driver–pressure–state–impacts–response (DPSIR) scheme of indicators. Ocean & Coastal Management, 50(5-6), 463-480.
Roberts CM, Halpern B, Palumbi SR, Warner RR (2006). Designing Marine Reserve Networks Why Small, Isolated Protected Areas Are Not Enough. Conservation, 2(3), 10-17.
Hawkins JP, Roberts CM, Dytham C, Schelten C, Nugues MM (2006). Effects of habitat characteristics and sedimentation on performance of marine reserves in St. Lucia.
Biological Conservation,
127(4), 487-499.
Abstract:
Effects of habitat characteristics and sedimentation on performance of marine reserves in St. Lucia
This study examines factors affecting the rate and extent of biomass build-up among commercially important groupers, snappers, grunts, parrotfish and surgeonfish in a network of four marine reserves in southwest St. Lucia, Caribbean. Reserves constituted 35% of the total reef area originally available for fishing. Protection was instigated in 1995 after a baseline survey with annual or biennial censuses performed until 2002. Each survey consisted of 114 fifteen minute fish counts in reserves and 83 in fishing grounds, at depths of 5 m and 15 m in a 10 m diameter counting area. Estimates of number and size (cm) of target species were used to calculate fish family biomass. Data were analysed using three-way ANOVA in a before-after-control-impact pairs (BACIP) design. All families increased significantly in biomass over time at nearly all sites. Increases were greater in reserves than fishing grounds, except for grunts, and responses were strongest in parrotfish and surgeonfish. The combined biomass of families more than quadrupled in reserves and tripled in fishing grounds between 1995 and 2002. During this period coral cover declined by 46% in reserves and 35% in fishing grounds. Multiple regression showed that neither habitat characteristics nor habitat deterioration significantly affected rates of biomass build-up. The key factor was protection from fishing, which explained 44% of the variance in biomass growth. A further 28% of the variance was explained by sedimentation, a process known to stress reef invertebrates, significantly reducing the rate of biomass build-up. St. Lucia's reserves succeeded in producing significant gains to fish stocks despite coral cover and structural complexity falling steeply over the period of the study. © 2005 Elsevier Ltd. All rights reserved.
Abstract.
Mangi SC, Roberts CM (2006). Quantifying the environmental impacts of artisanal fishing gear on Kenya’s coral reef ecosystems. Marine Pollution Bulletin, 52(12), 1646-1660.
Rodwell LD, Roberts CM (2006). Reply to the comment by Holland and Stokes on "Fishing and the impact of marine reserves in a variable environment". Canadian Journal of Fisheries and Aquatic Sciences, 63(5), 1186-1188.
Sáenz-Arroyo A, Roberts CM, Torre J, Cariño-Olvera M, Hawkins JP (2006). The value of evidence about past abundance: Marine fauna of the Gulf of California through the eyes of 16th to 19th century travellers.
Fish and Fisheries,
7(2), 128-146.
Abstract:
The value of evidence about past abundance: Marine fauna of the Gulf of California through the eyes of 16th to 19th century travellers
Eyewitness accounts written by early travellers to 'the new worlds' provide valuable insights into how seascapes once looked. Although this kind of information has been widely used to chart human impacts on terrestrial ecosystems, it has been greatly overlooked in the marine realm. Here we present a synthesis of 16th to 19th century travellers' descriptions of the Gulf of California and its marine wildlife. The diaries written by conquerors, pirates, missionaries and naturalists described a place in which whales were 'innumerable,' turtles were 'covering the sea' and large fish were so abundant that they could be taken by hand. Beds of pearl oysters that are described had disappeared by 1940 and only historical documents reveal the existence of large, widespread, deep pearl oyster reefs, whose ecology and past functions we know little about. Disqualifying the testimonies of early visitors to a region as 'anecdotal' is dangerous; it may lead to setting inappropriate management targets that could lead to the extinction of species that are rare today but were once much more abundant. Moreover, it represents unfair historical judgement on the work of early natural historians, scholars and scientists. We suggest that the review and analytical synthesis of reports made by early travellers should become part of the pre-requisites for deciding how to manage marine ecosystems today. © 2006 Blackwell Publishing Ltd.
Abstract.
Graham RT, Roberts CM, Smart JCR (2005). Diving behaviour of whale sharks in relation to a predictable food pulse. Journal of the Royal Society Interface, 3(6), 109-116.
Senz-Arroyo A, Roberts C, Torre J, Cario-Olvera M, Enrquez-Andrade R (2005). Rapidly shifting environmental baselines among fishers of the Gulf of California. Proceedings of the Royal Society B, 272(1575), 1957-1962.
Hawkins JP, Roberts CM, Kooistra D, Buchan K, White S (2005). Sustainability of scuba diving tourism on coral reefs of Saba.
Coastal Management,
33(4), 373-387.
Abstract:
Sustainability of scuba diving tourism on coral reefs of Saba
We examine the effects of recreational scuba diving in the Saba Marine Park in the Netherlands Antilles over a nine-year period. Levels of diving have remained low whereas dive fees have provided a major source of income to this park. We studied 5 dive sites where the average number of dives per site per year ranged from 445 to 2,163. At each site we recorded benthic parameters and levels of damage within at least 25 randomly placed quadrats in areas designated to be High use (0-20 m from mooring) or Low use (40-60 m from moorings), at yearly or biennial intervals. Within the same dive site, there was significantly more broken coral and fragments of live coral in High use areas than Low use. However, across sites, damage was not significantly related to diving intensity and nor did it accumulate over time. The Saba Marine Park shows that it is possible to fund protection at sustainable levels of use. Copyright © Taylor & Francis Inc.
Abstract.
Roberts CM, Hawkins JP, Gell FR (2005). The role of marine reserves in achieving sustainable fisheries.
Philosophical Transactions of the Royal Society B: Biological Sciences,
360(1453), 123-132.
Abstract:
The role of marine reserves in achieving sustainable fisheries
Many fishery management tools currently in use have conservation value. They are designed to maintain stocks of commercially important species above target levels. However, their limitations are evident from continuing declines in fish stocks throughout the world. We make the case that to reverse fishery declines, safeguard marine life and sustain ecosystem processes, extensive marine reserves that are off limits to fishing must become part of the management strategy. Marine reserves should be incorporated into modern fishery management because they can achieve many things that conventional tools cannot. Only complete and permanent protection from fishing can protect the most sensitive habitats and vulnerable species. Only reserves will allow the development of natural, extended age structures of target species, maintain their genetic variability and prevent deleterious evolutionary change from the effects of fishing. Species with natural age structures will sustain higher rates of reproduction and will be more resilient to environmental variability. Higher stock levels maintained by reserves will provide insurance against management failure, including risk-prone quota setting, provided the broader conservation role of reserves is firmly established and legislatively protected. Fishery management measures outside protected areas are necessary to complement the protection offered by marine reserves, but cannot substitute for it. © 2005 the Royal Society.
Abstract.
Sáenz–Arroyo A, Roberts CM, Torre J, Cariño‐Olvera M (2005). Using fishers’ anecdotes, naturalists’ observations and grey literature to reassess marine species at risk: the case of the Gulf grouper in the Gulf of California, Mexico. Fish and Fisheries, 6(2), 121-133.
Roberts CM (2004). Advocating against advocacy in fisheries management Fisheries Ecology and Management by Carl J. Walters and Steven J.D. Martell. Princeton University Press, 2004. US$99.50/US$45.00 hbk/pbk (448 pages) ISBN 0 691 11544 3. Trends in Ecology & Evolution, 19(9), 462-463.
Hawkins JP, Roberts CM (2004). Effects of Artisanal Fishing on Caribbean Coral Reefs.
Conservation Biology,
18(1), 215-226.
Abstract:
Effects of Artisanal Fishing on Caribbean Coral Reefs
Although the impacts of industrial fishing are widely recognized, marine ecosystems are generally considered less threatened by artisanal fisheries. To determine how coral reef fish assemblages and benthic communities are affected by artisanal fishing, we studied six Caribbean islands on which fishing pressure ranged from virtually none in Bonaire, increasing through Saba, Puerto Rico, St Lucia, and Dominica, and reaching very high intensities in Jamaica. Using stationary-point fish counts at 5 m and 15 m depth, we counted and estimated the lengths of all noncryptic, diurnal fish species within replicate 10-m-diameter areas. We estimated percent cover of coral and algae and determined reef structural complexity. From fish numbers and lengths we calculated mean fish biomass per count for the five most commercially important families. Groupers (Serranidae), snappers (Lutjanidae), parrotfish (Scaridae), and surgeonfish (Acanthuridae) showed order-of-magnitude differences in biomass among islands. Biomass fell as fishing pressure increased. Only grunts (Haemulidae) did not follow this pattern. Within families, larger-bodied species decreased as fishing intensified. Coral cover and structural complexity were highest on little-fished islands and lowest on those most fished. By contrast, algal cover was an order of magnitude higher in Jamaica than in Bonaire. These results suggest that following the Caribbean-wide mass mortality of herbivorous sea urchins in 1983-1984 and consequent declines in grazing pressure on reefs, herbivorous fishes have not controlled algae overgrowing corals in heavily fished areas but have restricted growth in lightly fished areas. In summary, differences among islands in the structure offish and benthic assemblages suggest that intensive artisanal fishing has transformed Caribbean reefs.
Abstract.
Hawkins JP, Roberts CM (2004). Effects of fishing on sex-changing Caribbean parrotfishes.
Biological Conservation,
115(2), 213-226.
Abstract:
Effects of fishing on sex-changing Caribbean parrotfishes
We studied parrotfish (Scaridae) assemblages on coral reefs in relation to fishing pressure around six Caribbean islands. Fishing intensity ranged from virtually none in Bonaire, and increased through Saba, Puerto Rico, St Lucia and Dominica to extremely high levels in Jamaica. In St Lucia we also compared parrotfish assemblages between fishing grounds and fully protected marine reserves, from 1995, 6 months prior to establishment, to 2001. Within each country we performed replicate counts of the number and size of all parrotfish species within, or passing through our counting area. From these data we calculated biomass for seven species. Biomass of the two largest species, Sparisoma viride and Scarus vetula, was greatest in islands with low fishing pressure (P < 0.001). By contrast, smaller species constituted an increasing proportion of the total parrotfish assemblage as fishing pressure increased (P < 0.001 in all cases). Parrotfish are protogynous hermaphrodites with two distinct colour phases. The initial phase is predominantly female, and the terminal phase exclusive to sexually mature males. The average size of all species except Sc. vetula tended to decrease with increasing fishing pressure. Furthermore, percentages of fish that were terminal phase males showed order of magnitude declines with increasing fishing pressure for Sp. viride and Sc. vetula. Terminal males of these species were absent from counts in Jamaica and virtually absent from Dominica suggesting that persistence of these populations may depend on recruitment from distant sources. Following reserve implementation in St Lucia, all species, except uncommon Sp. chrysopterum, increased in mean biomass (P < 0.001 in all cases). In 6 years the total biomass for all species combined increased to become nearly four times as high in reserves and almost twice as high in fishing grounds [P < 0.001 (year effect); P < 0.001 (protection effect); P < 0.001 (yearxprotection)], and mean size of five species increased significantly in both reserves and fishing grounds. © 2003 Elsevier Ltd. All rights reserved.
Abstract.
Rodwell LD, Roberts CM (2004). Fishing and the impact of marine reserves in a variable environment.
Canadian Journal of Fisheries and Aquatic Sciences,
61(11), 2053-2068.
Abstract:
Fishing and the impact of marine reserves in a variable environment
We use discrete-time models to investigate the impact of marine reserve establishment on fishery catch and biomass levels in open-access and quota-regulated fisheries under conditions of recruitment variability and natural mortality events. We find that under the conditions of variability tested, reserves can increase the probability of achieving target levels of biomass (60%, 35%, and 5% of carrying capacity) and can reduce catch variability in neighbouring fisheries, making future planning in the fishery more efficient. The size of the reserve required to meet each objective will depend on the initial condition of the stock and the exploitation rate in the fishery. Reserve coverage of between 20% and 40% prevent stock collapse in most cases. In heavily exploited fisheries, reserves are also likely to enhance mean catches, particularly in highly variable systems. If the stock has previously been heavily exploited, large reserves (≥60%) may be required to significantly increase the probability of achieving target biomass levels. However, once stocks have recovered, reserve coverage may be reduced without a reduction in this probability of success. © 2004 NRC Canada.
Abstract.
Duda TF, Bingham JP, Livett BG, Kohn AJ, Massilia GR, Schultz JR, Down J, Sandall D, Sweedler JV, Fainzilber M, et al (2004). How Much at Risk Are Cone Snails? [3] (multiple letters). Science, 303(5660), 955-957.
Barker NHL, Roberts CM (2004). Scuba diver behaviour and the management of diving impacts on coral reefs.
Biological Conservation,
120(4), 481-489.
Abstract:
Scuba diver behaviour and the management of diving impacts on coral reefs
Coral reefs worldwide are attracting increasing numbers of scuba divers, leading to growing concern about damage. There is now a need to manage diver behaviour closely, especially as many dive companies offer unlimited, unsupervised day and night diving from shore. We observed 353 divers in St. Lucia and noted all their contacts with the reef during entire dives to quantify rates of damage and seek ways of reducing it. Divers using a camera caused significantly more contacts with the reef than did those without cameras (mean 0.4 versus 0.1 contacts min -1), as did shore versus boat dives (mean 0.5 versus 0.2 contacts min -1) and night versus day dives (mean 1.0 versus 0.4 contacts min -1). We tested the effect of a one-sentence inclusion in a regular dive briefing given by local staff that asked divers to avoid touching the reef. We also examined the effect of dive leader intervention on rates of diver contact with the reef. Briefing alone had no effect on diver contact rates, or on the probability of a diver breaking living substrate. However, dive leader intervention when a diver was seen to touch the reef reduced mean contact rates from 0.3 to 0.1 contacts min -1 for both shore and boat dives, and from 0.2 to 0.1 contacts min -1 for boat dives. Given that briefings alone are insufficient to reduce diver damage, we suggest that divers need close supervision, and that dive leaders must manage diver behaviour in situ. © 2004 Elsevier Ltd. All rights reserved.
Abstract.
Barrett JH, Locker AM, Roberts CM (2004). The origins of intensive marine fishing in medieval Europe: the English evidence. Proceedings of the Royal Society B, 271(1556), 2417-2421.
Balmford A, Gravestock P, Hockley N, McClean CJ, Roberts CM (2004). The worldwide costs of marine protected areas. Proceedings of the National Academy of Sciences of the United States of America, 101(26), 9694-9697.
Roberts CM, Branch G, Bustamante RH, Castilla JC, Dugan J, Halpern BS, Lafferty KD, Leslie H, Lubchenco J, McArdle D, et al (2003). Application of ecological criteria in selecting marine reserves and developing reserve networks.
Ecological Applications,
13(1 SUPPL.).
Abstract:
Application of ecological criteria in selecting marine reserves and developing reserve networks
Marine reserves are being established worldwide in response to a growing recognition of the conservation crisis that is building in the oceans. However, designation of reserves has been largely opportunistic, or protective measures have been implemented (often overlapping and sometimes in conflict) by different entities seeking to achieve different ends. This has created confusion among both users and enforcers, and the proliferation of different measures provides a false sense of protection where little is offered. This paper sets out a procedure grounded in current understanding of ecological processes, that allows the evaluation and selection of reserve sites in order to develop functional, interconnected networks of fully protected reserves that will fulfill multiple objectives. By fully protected we mean permanently closed to fishing and other resource extraction. We provide a framework that unifies the central aims of conservation and fishery management, while also meeting other human needs such as the provision of ecosystem services (e.g. maintenance of coastal water quality, shoreline protection, and recreational opportunities). In our scheme, candidate sites for reserves are evaluated against 12 criteria focused toward sustaining the biological integrity and productivity of marine systems at both local and regional scales. While a limited number of sites will be indispensable in a network, many will be of similar value as reserves, allowing the design of numerous alternative, biologically adequate networks. Devising multiple network designs will help ensure that ecological functionality is preserved throughout the socioeconomic evaluation process. Too often, socioeconomic criteria have dominated the process of reserve selection, potentially undermining their efficacy. We argue that application of biological criteria must precede and inform socioeconomic evaluation, since maintenance of ecosystem functioning is essential for meeting all of the goals for reserves. It is critical that stakeholders are fully involved throughout this process. Application of the proposed criteria will lead to networks whose multifunctionality will help unite the objectives of different management entities, so accelerating progress toward improved stewardship of the oceans.
Abstract.
Gell FR, Roberts CM (2003). Benefits beyond boundaries: the fishery effects of marine reserves.
Trends in Ecology and Evolution,
18(9), 448-455.
Abstract:
Benefits beyond boundaries: the fishery effects of marine reserves
Marine reserves are areas of the sea where fishing is not allowed. They provide refuges where populations of exploited species can recover and habitats modified by fishing can regenerate. In some places, closed areas have been used for fisheries management for centuries [1] and, until recently, natural refugia also existed, inaccessible through depth, distance or adverse conditions. Developments in technology have left few areas of fishing interest beyond our reach. Recently, the idea of marine reserves as fisheries management tools has re-emerged with developing interest in ecosystem-based management, and observations of incidental fisheries benefits from reserves established for conservation. In light of new evidence, we argue that, by integrating large-scale networks of marine reserves into fishery management, we could reverse global fishery declines and provide urgently needed protection for marine species and their habitats.
Abstract.
Roberts CM, Andelman S, Branch G, Bustamante RH, Castilla JC, Dugan J, Halpern BS, Lafferty KD, Leslie H, Lubchenco J, et al (2003). ECOLOGICAL CRITERIA FOR EVALUATING CANDIDATE SITES FOR MARINE RESERVES. Ecological Applications, 13(sp1), 199-214.
Roberts CM, Andelman S, Branch G, Bustamante RH, Castilla JC, Dugan J, Halpern BS, Lafferty KD, Leslie H, Lubchenco J, et al (2003). Ecological criteria for evaluating candidate sites for marine reserves.
Ecological Applications,
13(1 SUPPL.).
Abstract:
Ecological criteria for evaluating candidate sites for marine reserves
Several schemes have been developed to help select the locations of marine reserves. All of them combine social, economic, and biological criteria, and few offer any guidance as to how to prioritize among the criteria identified. This can imply that the relative weights given to different criteria are unimportant. Where two sites are of equal value ecologically, then socioeconomic criteria should dominate the choice of which should be protected. However, in many cases, socioeconomic criteria are given equal or greater weight than ecological considerations in the choice of sites. This can lead to selection of reserves with little biological value that fail to meet many of the desired objectives. To avoid such a possibility, we develop a series of criteria that allow preliminary evaluation of candidate sites according to their relative biological values in advance of the application of socioeconomic criteria. We include criteria that, while not strictly biological, have a strong influence on the species present or ecological processes. Our scheme enables sites to be assessed according to their biodiversity, the processes which underpin that diversity, and the processes that support fisheries and provide a spectrum of other services important to people. Criteria that capture biodiversity values include biogeographic representation, habitat representation and heterogeneity, and presence of species or populations of special interest (e.g. threatened species). Criteria that capture sustainability of biodiversity and fishery values include the size of reserves necessary to protect viable habitats, presence of exploitable species, vulnerable life stages, connectivity among reserves, links among ecosystems, and provision of ecosystem services to people. Criteria measuring human and natural threats enable candidate sites to be eliminated from consideration if risks are too great, but also help prioritize among sites where threats can be mitigated by protection. While our criteria can be applied to the design of reserve networks, they also enable choice of single reserves to be made in the context of the attributes of existing protected areas. The overall goal of our scheme is to promote the development of reserve networks that will maintain biodiversity and ecosystem functioning at large scales. The values of ecosystem goods and services for people ultimately depend on meeting this objective.
Abstract.
Roberts CM (2003). Our shifting perspectives on the oceans. Oryx, 37(2), 166-177.
Nugues MM, Roberts CM (2003). Partial mortality in massive reef corals as an indicator of sediment stress on coral reefs. Marine Pollution Bulletin, 46(3), 314-323.
Chivian E, Roberts CM, Bernstein AS (2003). The Threat to Cone Snails. Science, 302(5644), 391-391.
Rodwell LD, Barbier EB, Roberts CM, McClanahan TR (2003). The importance of habitat quality for marine reserve – fishery linkages. Canadian Journal of Fisheries and Aquatic Sciences, 60(2), 171-181.
Milner-Gulland EJ, Bennett EL, Abernethy K, Bakarr M, Bennett E, Bodmer R, Brashares J, Cowlishaw G, Elkan P, Eves H, et al (2003). Wild meat: the bigger picture.
Trends in Ecology and Evolution,
18(7), 351-357.
Abstract:
Wild meat: the bigger picture
Massive overhunting of wildlife for meat across the humid tropics is now causing local extinctions of numerous species. Rural people often rely heavily on wild meat, but, in many areas, this important source of food and income is either already lost or is being rapidly depleted. The problem can only be tackled by looking at the wider economic and institutional context within which such hunting occurs, from household economics to global terms of trade. Conservation efforts must be placed within a landscape context; a mosaic of hunted and no-take areas might balance conservation with continued subsistence use. Successful conservation of hunted wildlife requires collaboration at all scales, involving local people, resource extraction companies, governments and scientists.
Abstract.
Rodwell LD, Barbier EB, Roberts CM, McCLanahan TR (2002). A model of tropical marine reserve-fishery linkages.
Natural Resource Modeling,
15(4), 453-486.
Abstract:
A model of tropical marine reserve-fishery linkages
The excessive and unsustainable exploitation of our marine resources has led to the promotion of marine reserves as a fisheries management tool. Marine reserves, areas in which fishing is restricted or prohibited, can offer opportunities for the recovery of exploited stock and fishery enhancement. In this paper we examine the contribution of fully protected tropical marine reserves to fishery enhancement by modeling marine reserve-fishery linkages. The consequences of reserve establishment on the long-run equilibrium fish biomass and fishery catch levels are evaluated. In contrast to earlier models this study highlights the roles of both adult (and juvenile) fish migration and larval dispersal between the reserve and fishing grounds by employing a spawner-recruit model. Uniform larval dispersal, uniform larval retention and complete larval retention combined with zero, moderate and high fish migration scenarios are analyzed in turn. The numerical simulations are based on Mombasa Marine National Park, Kenya, a fully protected coral reef marine reserve comprising approximately 30% of former fishing grounds. Simulation results suggest that the establishment of a fully protected marine reserve will always lead to an increase in total fish biomass. If the fishery is moderately to heavily exploited, total fishery catch will be greater with the reserve in all scenarios of fish and larval movement. If the fishery faces low levels of exploitation, catches can be optimized without a reserve but with controlled fishing effort. With high fish migration from the reserve, catches are optimized with the reserve. The optimal area of the marine reserve depends on the exploitation rate in the neighboring fishing grounds. For example, if exploitation is maintained at 40%, the ‘optimal’ reserve size would be 10%. If the rate increases to 50%, then the reserve needs to be 30% of the management area in order to maximize catches. However, even in lower exploitation fisheries (below 40%), a small reserve (up to 20%) provides significantly higher gains in fish biomass than losses in catch. Marine reserves are a valuable fisheries management tool. To achieve maximum fishery benefits they should be complemented by fishing effort controls. © 2002 Rocky Mountain Mathematics Consortium.
Abstract.
Baird AH, Bellwood DR, Connell JH, Cornell HV, Hughes TP, Karlson RH, Rosen BR, Briggs JC, Roberts CM, McClean CJ, et al (2002). Coral reef biodiversity and conservation [2] (multiple letters). Science, 296(5570), 1026-1028.
Roberts CM (2002). Deep impact: the rising toll of fishing in the deep sea.
Trends in Ecology and Evolution,
17(5), 242-245.
Abstract:
Deep impact: the rising toll of fishing in the deep sea
The deep ocean is one of the last great wildernesses. Waters deeper than 1000 m cover an estimated 62% of the planet. In spite of more than 150 years of exploration, the ocean depths remain virtually unknown. Biological science has so far touched upon only one millionth of the deep-sea floor, but new technology is revealing unknown and exotic habitats as quickly as we look. Those technologies are also bringing the deep within reach of industry, with devastating consequences.
Abstract.
Roberts CM, Sargant H (2002). Fishery benefits of fully protected marine reserves: Why habitat and behavior are important.
Natural Resource Modeling,
15(4), 487-507.
Abstract:
Fishery benefits of fully protected marine reserves: Why habitat and behavior are important
Fully protected marine reserves, areas that are closed to all fishing, have attracted great interest for their potential to benefit fisheries. A wide range of models suggest reserves will be most effective for species that are relatively sedentary as adults but produce offspring that disperse widely. Adult spawning stocks will be secure from capture in reserves, while their offspring disperse freely into fishing grounds. Such species include animals like reef fish, mollusks and echino-derms, and models typically indicate that when they are over-fished, catches will be higher with reserves than without. By contrast, the same models suggest that reserves will be ineffective for animals that are mobile as adults species like cod, tuna or sharks. They remain vulnerable to fishing whenever they move outside reserves. Unfortunately, most models lack sufficient realism to effectively gauge reserve effects on migratory species. They usually assume that individuals are homogeneously distributed in a uniform sea and move randomly. They also assume that fishers hunt at random. Neither is true. For centuries, fishers have targeted places and times when their quarry are most vulnerable to capture. Protecting these sites could have disproportionately large effects on stocks. Furthermore, models rarely take into account possible benefits from improvements in habitat within reserves. Such changes, like increased biomass and complexity of bottom-living organisms, could alter fish movement patterns and reduce natural mortality rates in ways that enhance reserve benefits. We present a simple model of reserve effects on a migratory fish species. The model incorporates spatial variation in vulnerability to capture and shows that strategically placed reserves can offer benefits in the form of increased spawning stock and catch, especially when fishing intensities are high. We need to develop a new generation of models that incorporate habitat and behaviour to better explore the utility of reserves for mobile species. Migratory behavior does not preclude reserves from benefiting a species, but it demands that we apply different principles in designing them. We must identify critical sites to species and develop reserve networks that focus protection on those places. © 2002 Rocky Mountain Mathematics Consortium.
Abstract.
Roberts CM, McClean CJ, Veron JEN, Hawkins JP, Allen GR, McAllister DE, Mittermeier CG, Schueler FW, Spalding M, Wells F, et al (2002). Marine biodiversity hotspots and conservation priorities for tropical reefs.
Science,
295(5558), 1280-1284.
Abstract:
Marine biodiversity hotspots and conservation priorities for tropical reefs
Coral reefs are the most biologically diverse of shallow water marine ecosystems but are being degraded worldwide by human activities and climate warming. Analyses of the geographic ranges of 3235 species of reef fish, corals, snails, and lobsters revealed that between 7.2% and 53.6% of each taxon have highly restricted ranges, rendering them vulnerable to extinction. Restricted-range species are clustered into centers of endemism, like those described for terrestrial taxa. The 10 richest centers of endemism cover 15.8% of the world's coral reefs (0.012% of the oceans) but include between 44.8 and 54.2% of the restricted-range species. Many occur in regions where reefs are being severely affected by people, potentially leading to numerous extinctions. Threatened centers of endemism are major biodiversity hotspots, and conservation efforts targeted toward them could help avert the loss of tropical reef biodiversity.
Abstract.
Tupper MH, Wickstrom K, Hilborn R, Roberts CM, Bohnsack JA, Gell F, Hawkins JP, Goodridge R (2002). Marine reserves and fisheries management. Science, 295(5558), 1233-1235.
Roberts CM (2002). Rapid Build‐up of Fish Biomass in a Caribbean Marine Reserve. Conservation Biology, 9(4), 815-826.
Pimm SL, Ayres M, Balmford A, Branch G, Brandon K, Brooks T, Bustamante R, Costanza R, Cowling R, Curran LM, et al (2001). Can We Defy Nature's End?. Science, 293(5538), 2207-2208.
Roberts CM, Bohnsack JA, Gell F, Hawkins JP, Goodridge R (2001). Effects of marine reserves on adjacent fisheries.
SCIENCE,
294(5548), 1920-1923.
Author URL.
Roberts CM, Ormsby A, Tschirhart J, Berger J, O’Hara JL, Johns D, Reid WV (2001). Emptying the Oceans of Fish. Conservation Biology, 13(1), 216-222.
Roberts CM (2001). What is Natural? Coral Reef Crisis J. Sapp; Oxford University Press, New York, 1999, 275 pages, hardback, ISBN 0-19-512364-6, £22.50 (US$30). Biological Conservation, 98(3), 381-385.
Pezzey JCV, Roberts CM, Urdal BT (2000). A simple bioeconomic model of a marine reserve. Ecological Economics, 33(1), 77-91.
Morris AV, Roberts CM, Hawkins JP (2000). The threatened status of groupers (Epinephelinae).
Biodiversity and Conservation,
9(7), 919-942.
Abstract:
The threatened status of groupers (Epinephelinae)
The marine environment has traditionally been considered to be resilient to human impacts. However, concern over growing threats to marine biodiversity has led to a renewed effort to assess and quantify risks to marine species. This study assesses threats to the subfamily Epinephelinae of the Serranidae (groupers), a commercially and ecologically important group of predatory fish which are heavily exploited throughout their range. Eighty-five tropical species of the subfamily are examined in detail and classified according to 1996 IUCN Red List categories. Thirty-seven species (43.5%) are considered Threatened, of which two (Cromileptes altivelis and Epinephelus akaara) are Endangered, and the remaining 35 are Vulnerable. Thirty-four species (40%) are listed as Lower Risk and do not appear to be under immediate threat. Fourteen species (16.5%) are Data Deficient. Most of the threatened species are wide ranging. Large range size and the production of abundant, dispersive offspring are characteristics of groupers that have previously been considered to make them unlikely candidates for extinction. However, rapidly intensifying fisheries employing habitat-destructive gears now encompass vast areas of the tropics, putting many species at risk. Members of the genera Epinephelus and Mycteroperca were found to he particularly at risk, probably due to their large body sizes, long life-span and late reproduction.
Abstract.
Hawkins JP, Roberts CM, Clark V (2000). The threatened status of restricted-range coral reef fish species.
ANIMAL CONSERVATION,
3, 81-88.
Author URL.
Hawkins JP, Roberts CM, Clark V (2000). The threatened status of restricted-range coral reef fish species.
Animal Conservation,
3(1), 81-88.
Abstract:
The threatened status of restricted-range coral reef fish species
Coral reefs are the most diverse ecosystem in the sea. Throughout the world they are being over-fished, polluted and destroyed, placing biodiversity at risk. To date, much of the concern over biodiversity loss has centred on local losses and the possibility of global extinction has largely been discounted. However, recent research has shown that 24% of reef fish species have restricted ranges (< 800 000 km2), with 9% highly restricted (< 50 000 km2). Restricted-range species are thought to face a greater risk of extinction than more widespread species since local impacts could cause global loss. We searched for information on status in the wild and characteristics of 397 restricted-range reef fish species. Fish body size, habitat requirements and usefulness to people were compared with those of a taxonomically-matched sample of more widespread species. We found that on average species with restricted ranges were significantly smaller (mean total length 19.1 cm versus 24.4 cm), tended to have narrower habitat requirements and were less used by people. Greater habitat specificity will tend to increase extinction risk while, if real, more limited usefulness (equivalent to exploitation) may reduce risk. Fifty-eight percent of restricted-range species were considered common/abundant in the wild and 42% uncommon/rare. Population status and threats to 319 species for which data were available were assessed according to the categories and criteria of the IUCN red list of threatened animals. A number of species were found to be rare, were exploited and had highly restricted ranges overlapping areas where reef degradation is particularly severe, placing them at a high risk of extinction. Five species were listed as Critically Endangered, two of them possibly already extinct in the wild, one as Endangered and 172 as Vulnerable. A further 126 species fell into Lower Risk categories and 11 were considered Data Deficient. Given the intensity of impacts to reefs, the broad geographical areas affected and the large numbers of restricted-range species, global extinctions seem likely. Urgent management action is now crucial for the survival of several species of reef fishes.
Abstract.
Hawkins JP, Roberts CM, Van't Hof T, De Meyer K, Tratalos J, Aldam C (1999). Effects of recreational scuba diving on Caribbean coral and fish communities.
Conservation Biology,
13(4), 888-897.
Abstract:
Effects of recreational scuba diving on Caribbean coral and fish communities
Scuba diving on coral reefs is an increasingly lucrative element of tourism in the tropics, but divers can damage the reefs on which tourism depends. By studying the effects of diving we can determine what level of use is justifiable in balancing objectives of economic gain and conservation. Off the Caribbean island of Bonaire we compared coral and fish communities between undived reserves and environmentally similar dive sites where maximum use reached 6000 dives per site per year. At these levels of diving, direct physical damage to reefs was relatively minor. There were more loose fragments of living coral in dive sites than reserves and more abraded coral in high- than low-use areas. Diving had no significant effect on reef fish communities. Between 1991 and 1994, diving intensity increased 70% and coral cover declined in two of three dive sites and in all three reserves, suggesting a background stress unrelated to tourism. There was a significant decline in the proportion of old colonies of massive coral species within dive sites (19.2% loss), compared to a smaller loss in reserves (6.7%). Branching corals increased by 8.2% in dive sites, compared with 2.2% in reserves. Despite close management of reefs, diving is changing the character of Bonaire's reefs by allowing branching corals to increase at the expense of large, massive colonies. The impact of background stresses on massive corals seems to have been greater in the presence of diving. Other studies have linked disease infection to coral tissue damage, and the higher rates of abrasion we recorded in dived sites could have rendered corals there more susceptible to disease, thus mediating the decline of massive corals. Our study shows that even relatively low levels of diving can have pronounced effects manifested in shifts in dominance patterns rather than loss of overall coral cover. Bonaire's reefs have among the highest coral cover and greatest representation of ancient coral colonies of reefs anywhere in the Caribbean. Conserving the character of these reefs may require tighter controls on diving intensity.
Abstract.
Roberts CM, Hawkins JP (1999). Extinction risk in the sea.
Trends in Ecology and Evolution,
14(6), 241-246.
Abstract:
Extinction risk in the sea
Jean Baptiste de Lamarck and Thomas Huxley, two of the foremost thinkers of the 18th and 19th centuries, believed that humanity could not cause the extinction of marine species. Their opinions reflected a widespread belief that the seas were an inexhaustible source of food and wealth of which people could barely use a fraction. Such views were given weight by the abundant fisheries of the time. Additionally, the incredible fecundity and wide distributions of marine fishes, combined with limited exploitation, provided ample justification for optimism. The ideas of Huxley and Lamarck persist to this day, despite a sea change in the scale and depth of our influence on the oceans. Marine species could be at a far greater risk of extinction than we have assumed.
Abstract.
Sladek Nowlis J, Roberts CM (1999). Fisheries benefits and optimal design of marine reserves.
Fishery Bulletin,
97(3), 604-616.
Abstract:
Fisheries benefits and optimal design of marine reserves
We used fishery population models to assess the potential for marine fishery reserves, areas permanently closed to fishing, to enhance long-term fishery yields. Our models included detailed life history data. They also included the key assumptions that adults did not cross reserve boundaries and that larvae mixed thoroughly across the boundary but were retained sufficiently to produce a stock-recruitment relationship for the management area. We analyzed the results of these models to determine how reserve size, fishing mortality, and life history traits, particularly population growth potential, affected the fisheries benefits from reserves. We predict that reserves will enhance catches from any overfished population that meets our assumptions, particularly heavily overfished populations with low population growth potential. We further predict that reserves can enhance catches when they make up 40% or more of fisheries management areas, significantly higher proportions than are typical of existing reserve systems. Finally, we predict that reserves in systems that meet our assumptions will reduce annual catch variation in surrounding fishing grounds. The fisheries benefits and optimal design of marine reserves in any situation depended on the life history of the species of interest as well as its rate of fishing mortality. However, the generality of our results across a range of species suggest that marine reserves are a viable fisheries management alternative.
Abstract.
Bellwood DR, Leis JM, Stobutzki IC, Sale PF, Cowen RK, Roberts CM (1998). Fishery and reef management [3] (multiple letters). Science, 279(5359), 2020-2022.
Roberts C (1998). No-take marine reserves: providing fishery and conservation benefits.
North Sea Monitor,
16(3), 4-8.
Abstract:
No-take marine reserves: providing fishery and conservation benefits
There is a growing realisation that current approaches to fishery management in Europe are failing to achieve sustainable harvests. Nor do they embrace the need for protection of marine species from the damage done to marine habitats by fishing. No-take marine reserves, areas completely closed to fishing, provide a much needed management tool capable of simultaneously delivering both fishery and conservation benefits.
Abstract.
Roberts CM (1998). Sources, sinks, and the design of marine reserve networks.
Fisheries,
23(7), 16-19.
Abstract:
Sources, sinks, and the design of marine reserve networks
Recently, enthusiasm has been growing for "source and sink" theory in understanding how dispersal influences replenishment of marine populations. Sources are areas that contribute disproportionately large quantities of recruits to future generations; sinks receive recruits but contribute little. This simple idea has been taken up by those seeking to optimize the location of no-take marine reserves. Reserves in source areas are argued to be better than those in sinks in terms of value for fisheries enhancement and conservation. However, attempting to identify sources and sinks is extremely difficult and may run contrary to management objectives by delaying reserve establishment. In any case, it is highly likely that different species have different source and sink areas and that the locations of such areas will change through time. The surest way to achieve fishery and conservation goals will be to establish dense networks of reserves that incorporate a wide variety of habitats and locations. We create source areas when we create no-take reserves.
Abstract.
Roberts CM (1997). Connectivity and Management of Caribbean Coral Reefs. Science, 278(5342), 1454-1457.
Roberts CM (1997). Ecological advice for the global fisher crisis. Trends in Ecology & Evolution, 12(1), 35-38.
Roberts CM, Hawkins JP (1997). How small can a marine reserve be and still be effective?.
CORAL REEFS,
16(3), 150-150.
Author URL.
Nowlis JS, Roberts CM, Smith AH, Siirila E (1997). Human-enhanced impacts of a tropical storm on nearshore coral reefs.
Ambio,
26(8), 515-521.
Abstract:
Human-enhanced impacts of a tropical storm on nearshore coral reefs
Land development ranks among the most significant human threats to coral reefs, causing damage by promoting the erosion and transport of soil - called sediment once suspended in water. We studied the impacts of sediment on the coral communities of St. Lucia following a tropical storm. We found more sediment and coral damage on reefs closest to the mouths of large rivers. Coral mortality exceeded 50% at some sites, and the degree of coral mortality and bleaching depended on the amount of sediment at the site. Despite exemplary efforts by engineers to reduce erosion rates, we found more sediment at sites near a road under construction at the time of the storm. Collectively, our data demonstrated a major negative impact of land development on coral reefs, a problem likely to grow in scale given the growing demands for developed land and the recent frequency of large storms in the tropical Atlantic.
Abstract.
Shulman MJ, Polunin NVC, Roberts CM (1997). Reef Fisheries. Ecology, 78(7).
Readman JW, Tolosa I, Law AT, Bartocci J, Azemard S, Hamilton T, Mee LD, Wagener A, Le Tissier M, Roberts C, et al (1996). Discrete bands of petroleum hydrocarbons and molecular organic markers identified within massive coral skeletons. Marine Pollution Bulletin, 32(5), 437-443.
ROBERTS CM (1995). Effects of Fishing on the Ecosystem Structure of Coral Reefs. Conservation Biology, 9(5), 988-995.
Roberts CM, Polunin NVC (1994). Hol Chan: Demonstrating that marine reserves can be remarkably effective. Coral Reefs, 13(2).
Roberts CM, Downing N, Price ARG (1994). Oil on troubled waters: impacts of the Gulf War on coral reefs.
Proceedings of the colloquium on global aspects of coral reefs, Miami, 1993, 132-138.
Abstract:
Oil on troubled waters: impacts of the Gulf War on coral reefs
During the 1991 Gulf War some 6-7 million barrels of oil were dumped into the Arabian Gulf. For 10 months an oily soot from blazing wells rained onto the region, obscuring the sun. Some inshore patch reefs covered by oil for several weeks suffered no more than an initial loss of mobile fauna. Offshore islands of Saudi Arabia were oiled but escaped lightly. Surveys in 1991 and 1992 suggest that these reefs remain remarkably unscathed. A survey of Kuwaiti island reefs in July 1991 also suggested an absence of subtidal effects. However, by May 1992 Kuwaiti reefs were showing signs of stress with extensive coral bleaching reported. In December 1992 they were resurveyed and data compared with surveys made before the war. Whilst there had been mortalities of Acropora and Porites at two of three islands visited, these were no greater in magnitude than kills prior to the Gulf War. Only on an inshore patch reef close to the source of the largest oil spill was a more widespread coral mortality noted. A significant decline in fish populations was also detected at Kubbar Island. Environmental stresses coupled with escalating human pressures make the long-term future for coral reefs in the Gulf very uncertain. -from Authors
Abstract.
Hawkins JP, Roberts CM (1994). The growth of coastal tourism in the Red Sea: Present and future effects on coral reefs. Ambio, 23(8), 503-508.
Hawkins JP, Roberts CM (1994). The growth of coastal tourism in the Red Sea: present and possible future effects on coral reefs.
Proceedings of the colloquium on global aspects of coral reefs, Miami, 1993, 385-391.
Abstract:
The growth of coastal tourism in the Red Sea: present and possible future effects on coral reefs
About 19% of Egypt's reefs are currently affected by tourism, but this is expected to rise to >26% by the year 2000. However, the intensity of effects on reefs is likely to increase much more during this period. Israel plans a further 50% increase in coastal tourism, Jordan 100% and Egypt a 13-fold expansion. Tourist development has already caused substantial damage to inshore reefs near Hurghada from infilling, sedimentation and over-fishing for marine curios. Elsewhere new constructions are also beginning to modify reef habitats. Until now damage to Sharm-el-Sheikh's reefs has been mainly caused by the direct effects of diving and snorkelling. Whilst current levels of recreational use appear to be sustainable, the massive expansion planned throughout the region will place the long-term future of reefs in doubt. The carrying capacity of coral reefs seems sure to be exceeded with widespread reef degradation the likely result. -from Authors
Abstract.
Roberts CM (1993). Coral reefs: Health, hazards and history. Trends in Ecology & Evolution, 8(12), 425-427.
Hawkins JP, Roberts CM (1993). Effects of Recreational Scuba Diving on Coral Reefs: Trampling on Reef-Flat Communities. Journal of Applied Ecology, 30(1).
Downing N, Roberts C (1993). Has the Gulf War affected coral reefs of the northwestern Gulf?. Marine Pollution Bulletin, 27, 149-156.
Roberts CM, Polunin NVC (1993). Marine reserves: simple solutions to managing complex fisheries?.
Ambio,
22(6), 363-368.
Abstract:
Marine reserves: simple solutions to managing complex fisheries?
Fisheries on coral reefs are highly complex, can be very productive, but typically have little or no management. Use of marine reserves has been suggested as an approach. Protective management potentially has several important benefits including protection of spawning stocks; provision of recruits to replenish fishing grounds; enhancement of catches in adjacent unprotected areas through emigration; minimal requirement for information on biology of stocks; and ease of enforcement. We evaluate the evidence available to test whether reserves function as predicted on theoretical grounds. In general, field studies from widespread sites around the globe support predictions of increases in abundance and average size of fishes in protected areas. However, evidence for enhanced catches in adjacent areas is more limited. Protective management appears to hold much promise for low-cost management of reef fisheries. -from Authors
Abstract.
Price ARG, Sheppard CRC, Roberts CM (1993). The Gulf: its biological setting. Marine Pollution Bulletin, 27, 9-15.
Roberts CM (1993). Trouble ahead for coral reefs. Marine Pollution Bulletin, 26(12), 709-710.
Roberts CM, Ormond RFG (1992). Butterflyfish social behaviour, with special reference to the incidence of territoriality: a review. Environmental Biology of Fishes, 34(1), 79-93.
Hawkins JP, Roberts CM (1992). Effects of recreational SCUBA diving on fore-reef slope communities of coral reefs.
Biological Conservation,
62(3), 171-178.
Abstract:
Effects of recreational SCUBA diving on fore-reef slope communities of coral reefs
This study investigated the effects of recreational SCUBA diving on the fore-reef slopes of coral reefs near Sharm-el-Sheikh, a popular resort in Egypt. Benthic communities were compared using randomly placed 1-m2 quadrats at three sites subdivided into heavily and little dived areas. There were significantly more damaged coral colonies, loose fragments of live coral, fragments of coral re-attached to the substratum, partially dead and abraded corals in areas heavily used by divers than in control areas. Damage to corals varied with growth form, branching forms being most vulnerable to breakage. Changes to communities at heavily and little dived sites were studied over 12 months using 3 × 3 m permanent quadrats. No significant increases in damage attributable to diving were detected for the three sites combined. However, when considered individually, the site which had experienced the greatest increase in diving appeared to have accumulated damage (broken coral) whereas the two others did not. For management purposes the results show that some reefs can sustain heavy levels of diving without apparent continued degradation. New dive sites can accumulate damage very rapidly. However, at the levels of diver use encountered during this study this may be more of an aesthetic than a biological problem. © 1992.
Abstract.
Roberts CM, Shepherd ARD, Ormond RFG (1992). Large-Scale Variation in Assemblage Structure of Red Sea Butterflyfishes and Angelfishes. Journal of Biogeography, 19(3).
Sheppard C, Price A, Roberts C (1992). Marine ecology of the Arabian region: patterns and processes in extreme tropical environments.
Marine ecology of the Arabian region: patterns and processes in extreme tropical environmentsAbstract:
Marine ecology of the Arabian region: patterns and processes in extreme tropical environments
The main purposes are to collate information of the region, to review marine systems and processes in the intertidal and shallow sublittoral parts of the Arabian seas, and to highlight human utilisation and environmental consequences. The first section presents the geological, geographical, climatic and oceanographic background to the area. The second section examines what is known of the region's marine communities, interpreting the relationships between the marine systems and physical conditions for: reefs and coral communities; coral reef fish assemblages; other reef components and processes; seaweeds and seasonality; seagrasses and other dynamic substrates; intertidal areas - mangal associated ecosystems, marshes, sabkha and beaches; and the pelagic system. The next section synthesizes and concludes the biogeographical material and interprets the effects of natural stress on the biota. The final section describes and discusses the human use and management of the region, including fisheries. -after Authors
Abstract.
Wrathall TJ, Roberts CM, Ormond RFG (1992). Territoriality in the butterflyfishChaetodon austriacus. Environmental Biology of Fishes, 34(3), 305-308.
Roberts CM, Polunin NVC (1991). Are marine reserves effective in management of reef fisheries?. Reviews in Fish Biology and Fisheries, 1(1), 65-91.
Hawkins JP, Roberts CM, Adamson T (1991). Effects of a phosphate ship grounding on a Red Sea coral reef. Marine Pollution Bulletin, 22(11), 538-542.
Roberts CM (1991). Kingdom of the Deep Colin Willock. Boxtree, London, 1990. 191 pp. £16.95. ISBN: 1-85283-100-6. Marine Pollution Bulletin, 22(2), 97-98.
Roberts CM (1991). Larval mortality and the composition of coral reef fish communities. Trends in Ecology & Evolution, 6(3), 83-87.
Roberts CM (1991). Trophic relationships in the marine environment M. Barnes and R. N. Gibson (Eds). Aberdeen University Press, 1990. 642 pp. Price £65. ISBN: 0-08-037982-6. Marine Pollution Bulletin, 22(3).
Scott P, Roberts CM (1989). Confirmation of the Specific Status of Abudefduf natalensis Hensley and Randall (Pisces: Pomacentridae). Ichthyology & Herpetology, 1989(1).
Roberts C, Sheppard C (1988). Oil spill at Sharm-el-Sheikh. Marine Pollution Bulletin, 19(3), 92-93.
Roberts CM (1987). Experimental analysis of resource sharing between herbivorous damselfish and blennies on the Great Barrier Reef. Journal of Experimental Marine Biology and Ecology, 111(1), 61-75.
Chapters
Rogers AD, Aburto-Oropeza O, Appeltans W, Assis J, Ballance LT, Cury P, Duarte C, Favoretto F, Kumagai J, Lovelock C, et al (2023). Critical Habitats and Biodiversity: Inventory, Thresholds and Governance. In (Ed) The Blue Compendium, Springer Nature, 333-392.
Precht WF, Aronson RB, Gardner TA, Gill JA, Hawkins JP, Hernández-Delgado EA, Jaap WC, McClanahan TR, McField MD, Murdoch TJT, et al (2020). The timing and causality of ecological shifts on Caribbean reefs. In (Ed)
Advances in Marine Biology, 331-360.
Abstract:
The timing and causality of ecological shifts on Caribbean reefs
Abstract.
Roberts CM, Reynolds JD, Côté IM, Hawkins JP (2012). Redesigning coral reef conservation. In (Ed) Coral Reef Conservation, Cambridge University Press (CUP), 515-537.
Tickell C, Ormond RFG, Roberts CM (2010). The biodiversity of coral reef fishes. In (Ed) Marine Biodiversity, Cambridge University Press (CUP), 216-257.
Barrett JH, Locker AM, Roberts CM (2009). 'Dark age economics' revisited: the English Fish-bone evidence, 600-1600. In (Ed) Northern World, 31-59.
Price ARG, Roberts CM, Hawkins JP (2009). Recreational Use of Coral Reefs in the Maldives and Caribbean. In (Ed) Conservation of Biological Resources, 242-260.
Barrett JH, Locker AM, Roberts CM (2009). ‘Dark Age Economics’ Revisited: the English Fish-Bone Evidence, 600–1600. In (Ed) Beyond the Catch, Brill Academic Publishers, 29-60.
Reynolds JD, Dulvy NK, Roberts CM (2008). Exploitation and Other Threats to Fish Conservation. In (Ed) Handbook of Fish Biology and Fisheries, 319-341.
Barker N, Roberts C (2007). Attitudes to and Preferences of Divers toward Regulation. In (Ed) New Frontiers in Marine Tourism: Diving Experiences, Sustainabilitv, Management, 171-188.
Barker N, Roberts C (2007). Attitudes to and preferences of divers toward regulation. In (Ed) New Frontiers in Marine Tourism, 171-187.
Polunin NVC, Roberts CM, Pauly D (1996). Developments in tropical reef fisheries science and management. In (Ed) Reef Fisheries, Springer Nature, 361-377.
Roberts CM (1996). Settlement and beyond: population regulation and community structure of reef fishes. In (Ed) Reef Fisheries, Springer Nature, 85-112.
McAllister DE, Schueler FW, Roberts CM, Hawkins JP (1994). Mapping and GIS analysis of the global distribution of coral reef fishes on an equal-area grid. In (Ed) Mapping the Diversity of Nature, Springer Nature, 155-175.
Conferences
Nugues MM, Roberts CM (2003). Coral mortality and interaction with algae in relation to sedimentation.
Abstract:
Coral mortality and interaction with algae in relation to sedimentation
Abstract.
Roberts CM (2000). Selecting marine reserve locations: Optimality versus opportunism.
Abstract:
Selecting marine reserve locations: Optimality versus opportunism
Abstract.
Roberts CM (1994). 'Deconstructing' coral reefs.
Publications by year
2024
Pérez G, O'Leary BC, Allegri E, Casal G, Cornet CC, de Juan S, Failler P, Fredriksen S, Fonseca C, Furlan E, et al (2024). A conceptual framework to help choose appropriate blue nature-based solutions.
J Environ Manage,
352Abstract:
A conceptual framework to help choose appropriate blue nature-based solutions.
Biodiversity loss and climate change have severely impacted ecosystems and livelihoods worldwide, compromising access to food and water, increasing disaster risk, and affecting human health globally. Nature-based Solutions (NbS) have gained interest in addressing these global societal challenges. Although much effort has been directed to NbS in urban and terrestrial environments, the implementation of NbS in marine and coastal environments (blue NbS) lags. The lack of a framework to guide decision-makers and practitioners through the initial planning stages appears to be one of the main obstacles to the slow implementation of blue NbS. To address this, we propose an integrated conceptual framework, built from expert knowledge, to inform the selection of the most appropriate blue NbS based on desired intervention objectives and social-ecological context. Our conceptual framework follows a four incremental steps structure: Step 1 aims to identify the societal challenge(s) to address; Step 2 highlights ecosystem services and the underlying biodiversity and ecological functions that could contribute to confronting the societal challenge(s); Step 3 identify the specific environmental context the intervention needs to be set within (e.g. the spatial scale the intervention will operate within, the ecosystem's vulnerability to stressors, and its ecological condition); and Step 4 provides a selection of potential blue NbS interventions that would help address the targeted societal challenge(s) considering the context defined through Step 3. Designed to maintain, enhance, recover, rehabilitate, or create ecosystem services by supporting biodiversity, the blue NbS intervention portfolio includes marine protection (i.e. fully, highly, lightly, and minimally protected areas), restorative activities (i.e. active, passive, and partial restoration; rehabilitation of ecological function and ecosystem creation), and other management measures (i.e. implementation and enforcement of regulation). Ultimately, our conceptual framework guides decision-makers toward a versatile portfolio of interventions that cater to the specific needs of each ecosystem rather than imposing a rigid, one-size-fits-all model. In the future, this framework needs to integrate socio-economic considerations more comprehensively and be kept up-to-date by including the latest scientific information.
Abstract.
Author URL.
Ayres KA, Lara-Lizardi F, Roberts CM, Pisco-Limones W, Klimley P, Jorgensen SJ, Galván-Magaña F, Hoyos-Padilla M, Ketchum JT (2024). Local diver knowledge reveals decline in scalloped hammerhead sharks (Sphyrna lewini) at seamounts in the southwestern Gulf of California.
Marine Policy,
159Abstract:
Local diver knowledge reveals decline in scalloped hammerhead sharks (Sphyrna lewini) at seamounts in the southwestern Gulf of California
The Gulf of California is a marginal sea that has seen widespread species declines due to fishing. The scalloped hammerhead shark (Sphyrna lewini) is a semi-pelagic species that form large schools at seamounts where they refuge during the day. El Bajo seamount off Espíritu Santo Island and Las Animas seamount off San José Island in the southern Gulf of California are long-established scuba-dive destinations for observing S. lewini. In this study local scuba-diver knowledge was used to determine changes in S. lewini school abundance over a 50 year period between 1970 and 2020. The abundance of S. lewini encountered per dive at El Bajo was reported to have significantly declined, falling by 97%, from an average of 150 sharks in the 1970 s to 5 sharks in the 2010 s and at Las Animas by 100%, from an average of 100 sharks in the 1970 s to 0 sharks in the 2010 s. A shifting baseline was evident and there was a significant relationship between the year participants had first dived the seamounts and the number they considered to be a ‘very abundant’ school of S. lewini (GAM p < 0.001). This study demonstrates the importance of collecting local ecological knowledge to document declines in species populations, especially for S. lewini which is currently listed as ‘Critically Endangered’ on the IUCN Red List.
Abstract.
2023
Rogers AD, Aburto-Oropeza O, Appeltans W, Assis J, Ballance LT, Cury P, Duarte C, Favoretto F, Kumagai J, Lovelock C, et al (2023). Critical Habitats and Biodiversity: Inventory, Thresholds and Governance. In (Ed) The Blue Compendium, Springer Nature, 333-392.
Epstein G, Roberts CM (2023). Does biodiversity-focused protection of the seabed deliver carbon benefits? a UK case study.
CONSERVATION LETTERS,
16(1).
Author URL.
O'Leary BC, Fonseca C, Cornet CC, de Vries MB, Degia AK, Failler P, Furlan E, Garrabou J, Gil A, Hawkins JP, et al (2023). Embracing Nature-based Solutions to promote resilient marine and coastal ecosystems. Nature-Based Solutions, 3, 100044-100044.
Fonseca C, Wood LE, Andriamahefazafy M, Casal G, Chaigneau T, Cornet CC, Degia AK, Failler P, Ferraro G, Furlan E, et al (2023). Survey data of public awareness on climate change and the value of marine and coastal ecosystems. Data in Brief, 47
2022
Rogers AD, Appeltans W, Assis J, Ballance LT, Cury P, Duarte C, Favoretto F, Hynes LA, Kumagai JA, Lovelock CE, et al (2022). Discovering marine biodiversity in the 21st century. , 93, 23-115.
Epstein G, Roberts CM (2022). Identifying priority areas to manage mobile bottom fishing on seabed carbon in the UK. PLOS Climate, 1(9).
Epstein G, Roberts CM (2022). Protecting seabed sediment carbon for climate mitigation: a UK case study.
Laffoley D, Baxter JM, Amon DJ, Claudet J, Downs CA, Earle SA, Gjerde KM, Hall-Spencer JM, Koldewey HJ, Levin LA, et al (2022). The forgotten ocean: Why COP26 must call for vastly greater ambition and urgency to address ocean change.
Aquatic Conservation: Marine and Freshwater Ecosystems,
32(1), 217-228.
Abstract:
The forgotten ocean: Why COP26 must call for vastly greater ambition and urgency to address ocean change
Of all the interconnected threats facing the planet, the top two are the climate and the biodiversity crises. Neither problem will be solved if we ignore the ocean. To turn the tide in favour of humanity and a habitable planet, we need to recognize and better value the fundamental role that the ocean plays in the earth system, and prioritize the urgent action needed to heal and protect the ocean at the ‘Earthscape’ level – the planetary scale at which processes to support life operate. The countries gathering at COP26 have unparalleled political capacity and leadership to make this happen. COP26 could be the turning point, but there must be commitment to united action for the ocean, as well as planning to meet those commitments, based on science-led solutions that address the interconnectivity of the ocean, climate, and biodiversity. Key ways in which the ocean both contributes to and acts as the major buffer for climate change are summarized, focusing on temperature, but not forgetting the role of storing carbon. It is noted with ‘high confidence’ that the ocean has stored 91% of the excess heat from global warming, with land, melting ice, and the atmosphere only taking up approximately 5, 3, and 1%, respectively. We also highlight the impact of the recent large release of heat from the ocean to the atmosphere during the 2015–2016 El Niño. We then present six science-based policy actions that form a recovery stimulus package for people, climate, nature, and the planet. Our proposals highlight what is needed to view, value, and treat the planet, including the ocean, for the benefit and future of all life.
Abstract.
Epstein G, Middelburg JJ, Hawkins JP, Norris CR, Roberts CM (2022). The impact of mobile demersal fishing on carbon storage in seabed sediments.
Global Change Biology,
28(9), 2875-2894.
Abstract:
The impact of mobile demersal fishing on carbon storage in seabed sediments
AbstractSubtidal marine sediments are one of the planet's primary carbon stores and strongly influence the oceanic sink for atmospheric CO2. By far the most widespread human activity occurring on the seabed is bottom trawling/dredging for fish and shellfish. A global first‐order estimate suggested mobile demersal fishing activities may cause 0.16–0.4 Gt of organic carbon (OC) to be remineralized annually from seabed sediment carbon stores (Sala et al. 2021). There are, however, many uncertainties in this calculation. Here, we discuss the potential drivers of change in seabed sediment OC stores due to mobile demersal fishing activities and conduct a literature review, synthesizing studies where this interaction has been directly investigated. Under certain environmental settings, we hypothesize that mobile demersal fishing would reduce OC in seabed stores due to lower production of flora and fauna, the loss of fine flocculent material, increased sediment resuspension, mixing and transport and increased oxygen exposure. Reductions would be offset to varying extents by reduced faunal bioturbation and community respiration, increased off‐shelf transport and increases in primary production from the resuspension of nutrients. Studies which directly investigated the impact of demersal fishing on OC stocks had mixed results. A finding of no significant effect was reported in 61% of 49 investigations; 29% reported lower OC due to fishing activities, with 10% reporting higher OC. In relation to remineralization rates within the seabed, four investigations reported that demersal fishing activities decreased remineralization, with three reporting higher remineralization rates. Patterns in the environmental and experimental characteristics between different outcomes were largely indistinct. More evidence is urgently needed to accurately quantify the impact of anthropogenic physical disturbance on seabed carbon in different environmental settings and to incorporate full evidence‐based carbon considerations into global seabed management.
Abstract.
2021
Duarte CM, Agusti S, Barbier E, Britten GL, Castilla JC, Gattuso J-P, Fulweiler RW, Hughes TP, Knowlton N, Lovelock CE, et al (2021). Author Correction: Rebuilding marine life. Nature, 593(7857), e1-e2.
Grorud-Colvert K, Sullivan-Stack J, Roberts C, Constant V, Horta E Costa B, Pike EP, Kingston N, Laffoley D, Sala E, Claudet J, et al (2021). The MPA Guide: a framework to achieve global goals for the ocean. Science, 373(6560).
Epstein G, Hawkins JP, Norris CR, Roberts CM (2021). The potential for mobile demersal fishing to reduce carbon storage and sequestration in seabed sediments.
Sumaila UR, Skerritt DJ, Schuhbauer A, Villasante S, Cisneros-Montemayor AM, Sinan H, Burnside D, Abdallah PR, Abe K, Addo KA, et al (2021). WTO must ban harmful fisheries subsidies.
Science,
374(6567).
Author URL.
2020
Roberts CM, O'Leary BC, Hawkins JP (2020). Climate change mitigation and nature conservation both require higher protected area targets.
Philosophical Transactions of the Royal Society B: Biological Sciences,
375(1794).
Abstract:
Climate change mitigation and nature conservation both require higher protected area targets
Nations of the world have, to date, pursued nature protection and climate change mitigation and adaptation policies separately. Both efforts have failed to achieve the scale of action needed to halt biodiversity loss or mitigate climate change.We argue that success can be achieved by aligning targets for biodiversity protection with the habitat protection and restoration necessary to bring down greenhouse gas concentrations and promote natural and societal adaptation to climate change. Success, however, will need much higher targets for environmental protection than the present 10% of sea and 17% of land. A new target of 30% of the sea given high levels of protection from exploitation and harm by 2030 is under consideration and similar targets are being discussed for terrestrial habitats. We make the case here that these higher targets, if achieved, would make the transition to a warmer world slower and less damaging for nature and people.
Abstract.
Laffoley D, Baxter JM, Amon DJ, Currie DEJ, Downs CA, Hall-Spencer JM, Harden-Davies H, Page R, Reid CP, Roberts CM, et al (2020). Eight urgent, fundamental and simultaneous steps needed to restore ocean health, and the consequences for humanity and the planet of inaction or delay.
Aquatic Conservation: Marine and Freshwater Ecosystems,
30(1), 194-208.
Abstract:
Eight urgent, fundamental and simultaneous steps needed to restore ocean health, and the consequences for humanity and the planet of inaction or delay
The ocean crisis is urgent and central to human wellbeing and life on Earth; past and current activities are damaging the planet's main life support system for future generations. We are witnessing an increase in ocean heat, disturbance, acidification, bio-invasions and nutrients, and reducing oxygen levels. Several of these act like ratchets: once detrimental or negative changes have occurred, they may lock in place and may not be reversible, especially at gross ecological and ocean process scales. Each change may represent a loss to humanity of resources, ecosystem function, oxygen production and species. The longer we pursue unsuitable actions, the more we close the path to recovery and better ocean health and greater benefits for humanity in the future. We stand at a critical juncture and have identified eight priority issues that need to be addressed in unison to help avert a potential ecological disaster in the global ocean. They form a purposely ambitious agenda for global governance and are aimed at informing decision-makers at a high level. They should also be of interest to the general public. of all the themes, the highest priority is to rigorously address global warming and limit surface temperature rise to 1.5°C by 2100, as warming is the pre-eminent factor driving change in the ocean. The other themes are establishing a robust and comprehensive High Seas Treaty, enforcing existing standards for Marine Protected Areas and expanding their coverage, especially in terms of high levels of protection, adopting a precautionary pause on deep-sea mining, ending overfishing and destructive fishing practices, radically reducing marine pollution, putting in place a financing mechanism for ocean management and protection, and lastly, scaling up science/data gathering and facilitating data sharing. By implementing all eight measures in unison, as a coordinated strategy, we can build resilience to climate change, help sustain fisheries productivity, particularly for low-income countries dependent on fisheries, protect coasts (e.g. via soft-engineering/habitat-based approaches), promote mitigation (e.g. carbon storage) and enable improved adaptation to rapid global change.
Abstract.
Stewart BD, Howarth LM, Wood H, Whiteside K, Carney W, Crimmins E, O'Leary BC, Hawkins JP, Roberts CM (2020). Marine Conservation Begins at Home: How a Local Community and Protection of a Small Bay Sent Waves of Change Around the UK and Beyond.
FRONTIERS IN MARINE SCIENCE,
7 Author URL.
O'Leary BC, Hoppit G, Townley A, Allen HL, McIntyre CJ, Roberts CM (2020). Options for managing human threats to high seas biodiversity. Ocean & Coastal Management, 187, 105110-105110.
Murray A, Garrud E, Ender I, Lee-Brooks K, Atkins R, Lynam R, Arnold K, Roberts C, Hawkins J, Stevens G, et al (2020). Protecting the million-dollar mantas; creating an evidencebased code of conduct for manta ray tourism interactions.
JOURNAL OF ECOTOURISM,
19(2), 132-147.
Author URL.
Duarte CM, Agusti S, Barbier E, Britten GL, Castilla JC, Gattuso J-P, Fulweiler RW, Hughes TP, Knowlton N, Lovelock CE, et al (2020). Rebuilding marine life. Nature, 580(7801), 39-51.
Burns P, Hawkins J, Roberts C (2020). Reconstructing the history of ocean wildlife around Ascension Island.
AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS,
30(6), 1220-1237.
Author URL.
Precht WF, Aronson RB, Gardner TA, Gill JA, Hawkins JP, Hernández-Delgado EA, Jaap WC, McClanahan TR, McField MD, Murdoch TJT, et al (2020). The timing and causality of ecological shifts on Caribbean reefs. In (Ed)
Advances in Marine Biology, 331-360.
Abstract:
The timing and causality of ecological shifts on Caribbean reefs
Abstract.
2019
Dyson F, Nelson A, Savage-Smith E, Pettifor A, Roberts C, Serageldin I, Ihekweazu C (2019). Books for our time: seven classics that speak to us now. Nature, 576(7787), 374-378.
O’Leary BC, Fieldhouse P, McClean CJ, Ford AES, Burns P, Hawkins JP, Roberts CM (2019). Evidence gaps and biodiversity threats facing the marine environment of the United Kingdom’s Overseas Territories.
Biodiversity and Conservation,
28(2), 363-383.
Abstract:
Evidence gaps and biodiversity threats facing the marine environment of the United Kingdom’s Overseas Territories
Understanding the evidence base and identifying threats to the marine environment is critical to ensure cost-effective management and to identify priorities for future research. The United Kingdom (UK) government is responsible for approximately 2% of the world’s oceans, most of which belongs to its 14 Overseas Territories (UKOTs). Containing biodiversity of global significance, and far in excess of the UK mainland’s domestic species, there has recently been a strong desire from many of the UKOTs, the UK Government, and NGOs to improve marine management in these places. Implementing evidence-based marine policy is, however, challenged by the disparate nature of scientific research in the UKOTs and knowledge gaps about the threats they face. Here, we address these issues by systematically searching for scientific literature which has examined UKOT marine biodiversity and by exploring publicly available spatial threat data. We find that UKOT marine biodiversity has received consistent, but largely low, levels of scientific interest, and there is considerable geographical and subject bias in research effort. of particular concern is the lack of research focus on management or threats to biodiversity. The extent and intensity of threats vary amongst and within the UKOTs but unsurprisingly, climate change associated threats affect them all and direct human stressors are more prevalent in those with higher human populations. To meet global goals for effective conservation and management, there is an urgent need for additional and continued investment in research and management in the Overseas Territories, particularly those that have been of lesser focus.
Abstract.
Precht WF, Aronson RB, Gardner TA, Gill JA, Hawkins JP, Hernández-Delgado EA, Jaap WC, Mcclanahan TR, Mcfield MD, Murdoch TJT, et al (2019). NON-RANDOM TIMING OF ECOLOGICAL SHIFTS ON CARIBBEAN CORAL REEFS SUGGESTS REGIONAL CAUSES OF CHANGE.
Johnson DE, Rees SE, Diz D, Jones PJS, Roberts C, Froján CB (2019). Securing effective and equitable coverage of marine protected areas: the UK's progress towards achieving Convention on Biological Diversity commitments and lessons learned for the way forward. Aquatic Conservation Marine and Freshwater Ecosystems, 29(S2), 181-194.
Roberts C (2019). There were walls of fish, so many you could hardly see the corals. Biologist, 66(3), 12-17.
2018
O'Leary BC, Ban NC, Fernandez M, Friedlander AM, García-Borboroglu P, Golbuu Y, Guidetti P, Harris JM, Hawkins JP, Langlois T, et al (2018). Addressing Criticisms of Large-Scale Marine Protected Areas.
BioScience,
68(5), 359-370.
Abstract:
Addressing Criticisms of Large-Scale Marine Protected Areas
Designated large-scale marine protected areas (LSMPAs, 100,000 or more square kilometers) constitute over two-thirds of the approximately 6.6% of the ocean and approximately 14.5% of the exclusive economic zones within marine protected areas. Although LSMPAs have received support among scientists and conservation bodies for wilderness protection, regional ecological connectivity, and improving resilience to climate change, there are also concerns. We identified 10 common criticisms of LSMPAs along three themes: (1) placement, governance, and management; (2) political expediency; and (3) social ecological value and cost. Through critical evaluation of scientific evidence, we discuss the value, achievements, challenges, and potential of LSMPAs in these arenas. We conclude that although some criticisms are valid and need addressing, none pertain exclusively to LSMPAs, and many involve challenges ubiquitous in management. We argue that LSMPAs are an important component of a diversified management portfolio that tempers potential losses, hedges against uncertainty, and enhances the probability of achieving sustainably managed oceans.
Abstract.
Sala E, Lubchenco J, Grorud-Colvert K, Novelli C, Roberts C, Sumaila UR (2018). Assessing real progress towards effective ocean protection. Marine Policy, 91, 11-13.
Stevens GMW, Hawkins JP, Roberts CM (2018). Courtship and mating behaviour of manta rays Mobula alfredi and M. birostris in the Maldives.
Journal of Fish Biology,
93(2), 344-359.
Abstract:
Courtship and mating behaviour of manta rays Mobula alfredi and M. birostris in the Maldives
The aim of this 14 year study was to elucidate the entire courtship and mating behaviour of manta rays Mobula alfredi and M. birostris using behavioural observations, video and photographic records. From 2003 to 2016, over 11,000 surveys were undertaken at known manta ray aggregation sites in the Maldives to record any observed manta rays reproductive activity. From 47,591 photo-ID sightings, 4,247 individual M. alfredi were identified and 226 individual M. birostris from 229 photo-ID sightings, all recorded at 22 atolls across 265 different sites. Courtship activity was observed on 206 surveys at 30 different sites. A total of 229 courtship events were recorded, with 90% (n = 205) of them occurring at cleaning sites. The observed courtship activity was categorised into seven distinct stages which are described in detail: initiation, endurance, evasion, pre-copulatory positioning, copulation, post-copulatory holding and separation. Photographs provide the first scientific record of the entirety of manta rays courtship and mating. Both M. alfredi and M. birostris appear to engage in the same elaborate courtship rituals, exhibiting the same behaviours during all stages of the courtship and mating process.
Abstract.
O'Leary BC, Roberts CM (2018). Ecological connectivity across ocean depths: Implications for protected area design. Global Ecology and Conservation, 15, e00431-e00431.
López-Angarita J, Tilley A, Hawkins JP, Pedraza C, Roberts CM (2018). Land use patterns and influences of protected areas on mangroves of the eastern tropical Pacific.
Biological Conservation,
227, 82-91.
Abstract:
Land use patterns and influences of protected areas on mangroves of the eastern tropical Pacific
Mangroves are one of the most productive ecosystems in the world, sustaining millions of coastal livelihoods. However, their area of occurrence has been greatly reduced over the last century. In this study, we identify potential drivers of land use and land cover change adjacent to mangroves on the Pacific shorelines of Colombia, Panama and Costa Rica. We also evaluate the effectiveness of protected areas at halting mangrove deforestation between 2000 and 2012. Across all countries, agriculture was the most dominant land use type adjacent to mangroves, inside and outside protected areas. Results show that a combined total of 564 ha were lost, representing an average loss rate of only 0.02% per year. 75% of the total mangrove loss occurred in locations outside protected areas, with only 138 ha cleared from inside protected areas. Results suggest current conservation policies for mangrove protection in the study countries are effective at reducing deforestation and set a positive example for regions where mangroves are in decline.
Abstract.
López-Angarita J, Tilley A, Díaz JM, Hawkins JP, Cagua EF, Roberts CM (2018). Winners and losers in area-based management of a small-scale fishery in the Colombian Pacific.
Frontiers in Marine Science,
5(FEB).
Abstract:
Winners and losers in area-based management of a small-scale fishery in the Colombian Pacific
The Pacific coast of Colombia has some of the most extensive mangrove forests in South America. As an isolated region and one of the country's poorest, coastal communities rely on fishing as a main source of animal protein and income. In an attempt to reverse declining trends of fisheries resources, in 2008, an Exclusive Zone of Artisanal Fishing closed to industrial fishing, was established by stakeholders in the Northern Chocó region. Here we present a case study to investigate the effects of this area-based management on fisheries productivity and catch composition. Fishery landings data from 2010 to 2013 are compared to those of a neighbouring region with no fisheries management. Catch per unit effort, mean weight landed, and number of landed individuals were calculated for mangrove and non-mangrove associated species by boat type and fishing gear. A set of mixed effects models were used to unpack the effects of multiple factors and their interactions on response variables. Results show that across fishing gears and time, mean catch per unit effort increased by 50% in the Exclusive Zone of Artisanal Fishing within 3 years. Fisheries here focused on offshore resources with 61% more fishing trips associated with motorised boats than in the unmanaged region, where fishing was predominantly in mangroves and close to the coast. This suggests that fisheries management may have played a role in reducing pressure on mangrove resources. However, area-based management may have also driven the displacement of fishing effort by excluding industrial trawlers, which then concentrated their activity in neighbouring areas.
Abstract.
2017
Plumeridge AA, Roberts CM (2017). Conservation targets in marine protected area management suffer from shifting baseline syndrome: a case study on the Dogger Bank. Marine Pollution Bulletin, 116(1-2), 395-404.
Roberts CM, O'Leary BC, McCauley DJ, Cury PM, Duarte CM, Lubchenco J, Pauly D, Sáenz-Arroyo A, Sumaila UR, Wilson RW, et al (2017). Marine reserves can mitigate and promote adaptation to climate change.
Proc Natl Acad Sci U S A,
114(24), 6167-6175.
Abstract:
Marine reserves can mitigate and promote adaptation to climate change.
Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future.
Abstract.
Author URL.
O'Leary BC, Winther-Janson M, Bainbridge JM, Aitken J, Hawkins JP, Roberts CM (2017). Reply to White et al.: Providing Perspective on Ocean Conservation Targets.
Conservation Letters,
10(3), 375-376.
Abstract:
Reply to White et al.: Providing Perspective on Ocean Conservation Targets
In O'Leary et al. (2016), we undertook a quantitative synthesis (rather than a true statistical meta-analysis) of research to consider how much of the sea should be protected to achieve various conservation and management goals. We aimed to provide perspective on the appropriateness of global marine protected area coverage targets, particularly the United Nations Sustainable Development Goal 14/Convention on Biological Diversity goals to protect >10% of the sea by 2020. White et al. (2017) question the methodology of our approach, and we offer the following response.
Abstract.
O'Leary BC, Roberts CM (2017). The Structuring Role of Marine Life in Open Ocean Habitat: Importance to International Policy. Frontiers in Marine Science, 4
Howarth LM, Dubois P, Gratton P, Judge M, Christie B, Waggitt JJ, Hawkins JP, Roberts CM, Stewart BD (2017). Trade-offs in marine protection: Multispecies interactions within a community-led temperate marine reserve.
ICES Journal of Marine Science,
74(1), 263-276.
Abstract:
Trade-offs in marine protection: Multispecies interactions within a community-led temperate marine reserve
This study investigated the effects of a community-led temperate marine reserve in Lamlash Bay, Firth of Clyde, Scotland, on commercially important populations of European lobster (Homarus gammarus), brown crab (Cancer pagurus), and velvet swimming crabs (Necora puber). Potting surveys conducted over 4 years revealed significantly higher catch per unit effort (cpue 109% greater), weight per unit effort (wpue 189% greater), and carapace length (10-15 mm greater) in lobsters within the reserve compared with control sites. However, likely due to low levels of recruitment and increased fishing effort outside the reserve, lobster catches decreased in all areas during the final 2 years. Nevertheless, catch rates remained higher within the reserve across all years, suggesting the reserve buffered these wider declines. Additionally, lobster cpue and wpue declined with increasing distance from the boundaries of the marine reserve, a trend which tag-recapture data suggested were due to spillover. Catches of berried lobster were also twice as high within the reserve than outside, and the mean potential reproductive output per female was 22.1% greater. It was originally thought that higher densities of lobster within the reserve might lead to greater levels of aggression and physical damage. However, damage levels were solely related to body size, as large lobsters >110 mm had sustained over 218% more damage than smaller individuals. Interestingly, catches of adult lobsters were inversely correlated with those of juvenile lobsters, brown crabs, and velvet crabs, which may be evidence of competitive displacement and/or predation. Our findings provide evidence that temperate marine reserves can deliver fisheries and conservation benefits, and highlight the importance of investigating multispecies interactions, as the recovery of some species can have knock-on effects on others.
Abstract.
2016
O'Leary BC, Winther-Janson M, Bainbridge JM, Aitken J, Hawkins JP, Roberts CM (2016). Effective Coverage Targets for Ocean Protection.
Conservation Letters,
9(6), 398-404.
Abstract:
Effective Coverage Targets for Ocean Protection
The UN's globally adopted Convention on Biological Diversity coverage target for marine protected areas (MPAs) is ≥10% by 2020. In 2014, the World Parks Congress recommended increasing this to ≥30%. We reviewed 144 studies to assess whether the UN target is adequate to achieve, maximize, or optimize six environmental and/or socioeconomic objectives. Results consistently indicate that protecting several tens-of-percent of the sea is required to meet goals (average 37%, median 35%, modal group 21–30%), greatly exceeding the 2.18% currently protected and the 10% target. The objectives we examined were met in 3% of studies with ≤10% MPA coverage, 44% with ≤30% coverage, and 81% with more than half the sea protected. The UN's 10% target appears insufficient to protect biodiversity, preserve ecosystem services, and achieve socioeconomic priorities. As MPA coverages generated from theoretical studies inherently depend on scenario(s) considered, our findings do not represent explicit recommendations but rather provide perspective on policy goals.
Abstract.
Bégin C, Schelten CK, Nugues MM, Hawkins J, Roberts C, Côté IM (2016). Effects of Protection and Sediment Stress on Coral Reefs in Saint Lucia.
PLoS One,
11(2).
Abstract:
Effects of Protection and Sediment Stress on Coral Reefs in Saint Lucia.
The extent to which Marine Protected Areas (MPAs) benefit corals is contentious. On one hand, MPAs could enhance coral growth and survival through increases in herbivory within their borders; on the other, they are unlikely to prevent disturbances, such as terrestrial runoff, that originate outside their boundaries. We examined the effect of spatial protection and terrestrial sediment on the benthic composition of coral reefs in Saint Lucia. In 2011 (10 to 16 years after MPAs were created), we resurveyed 21 reefs that had been surveyed in 2001 and analyzed current benthic assemblages as well as changes in benthic cover over that decade in relation to protection status, terrestrial sediment influence (measured as the proportion of terrigenous material in reef-associated sediment) and depth. The cover of all benthic biotic components has changed significantly over the decade, including a decline in coral and increase in macroalgae. Protection status was not a significant predictor of either current benthic composition or changes in composition, but current cover and change in cover of several components were related to terrigenous content of sediment deposited recently. Sites with a higher proportion of terrigenous sediment had lower current coral cover, higher macroalgal cover and greater coral declines. Our results suggest that terrestrial sediment is an important factor in the recent degradation of coral reefs in Saint Lucia and that the current MPA network should be complemented by measures to reduce runoff from land.
Abstract.
Author URL.
López-Angarita J, Roberts CM, Tilley A, Hawkins JP, Cooke RG (2016). Mangroves and people: Lessons from a history of use and abuse in four Latin American countries.
Forest Ecology and Management,
368, 151-162.
Abstract:
Mangroves and people: Lessons from a history of use and abuse in four Latin American countries
From native pre-Columbian subsistence economies to the modern global economy, mangroves have played an important role providing goods and services to human societies for millennia. More than 90% of the world's mangroves are located in developing countries, where rates of destruction are increasing rapidly and on large scales. In order to design effective conservation strategies, it is critical to understand the natural dynamics and anthropogenic drivers of these coastal wetland habitats. We use retrospective techniques to reconstruct mangrove forest history in the Eastern Tropical Pacific. We examine available, present day estimates of mangrove area and evaluate the representation of mangroves in the protected area systems of Costa Rica, Panama, Colombia and Ecuador, evaluating existing policies regarding mangroves. Archaeozoological evidence shows that mangroves were exploited for many thousands of years by pre-Columbian societies. Post-conquest deforestation prevailed during the next 400 years. Since 1990, despite increasingly positive attitudes towards mangroves and their inclusion in protected areas and conservation policies, mangrove cover has continued to decline due to expanding human activities (agriculture, aquaculture, coastal development), even in the presence of laws prohibiting their removal. Here we provide an historical ecology baseline of mangroves in the Eastern Tropical Pacific, from which to view current trends and map future trajectories. Given the myriad negative consequences of mangrove loss recorded worldwide, and the strong ecological connectivity of the region, developing effective strategies for mangrove management at an appropriate scale will be paramount to protect coastal livelihoods and biodiversity.
Abstract.
Hawkins JP, O'Leary BC, Bassett N, Peters H, Rakowski S, Reeve G, Roberts CM (2016). Public awareness and attitudes towards marine protection in the United Kingdom.
Marine Pollution Bulletin,
111(1-2), 231-236.
Abstract:
Public awareness and attitudes towards marine protection in the United Kingdom
Public perception research evaluating awareness and attitudes towards marine protection is limited in the United Kingdom (UK) and worldwide. Given public opinion can help drive policy and affect its successful delivery we conducted nationwide surveys in 2005, 2010 and 2015 to assess public knowledge of UK (England, Scotland and Wales) sea ‘health’ and management. Respondents from all three surveys were relatively pessimistic about sea ‘health’, perceiving this as poor-fair and largely in decline. Enthusiasm for marine conservation was high with almost two-thirds of respondents in each survey wanting > 40% of UK seas highly protected from fishing and damaging activities. In 2015 there was considerable dissatisfaction with the rate of progress in Marine Conservation Zone designation and over three-quarters of respondents considered dredging and trawling to be inappropriate in protected areas, contrary to management. The UK government and devolved administrations need to better align future conservation and management with public expectations.
Abstract.
Peters H, O'Leary BC, Hawkins JP, Roberts CM (2016). The cone snails of Cape Verde: Marine endemism at a terrestrial scale.
Global Ecology and Conservation,
7, 201-213.
Abstract:
The cone snails of Cape Verde: Marine endemism at a terrestrial scale
Cape Verde in the Eastern Atlantic is typical of many island groups in supporting a wealth of endemic species both terrestrial and marine. Marine gastropod molluscs of the genus Conus, commonly known as cone snails, occur in coastal tropical waters throughout the globe, but in Cape Verde their endemism reaches its apogee with 53 out of 56 species occurring nowhere else, the majority of which are restricted to single islands and frequently to single bays. However, Cape Verde is rapidly moving to a tourism-based economy with a projected boom in infrastructure development often coincidental with the shallow-water habitat of many range-restricted Conus. The conservation assessment of Conus to standards of the International Union for the Conservation of Nature (IUCN) Red List of Endangered Species, found that 45.3% of 53 species assessed from Cape Verde are threatened or near-threatened with extinction compared to 7.4% of 579 species in the rest of the world. The only three Conus species globally assessed as Critically Endangered and on the cusp of extinction are all endemic to Cape Verde. Our analysis of Conus species distribution, together with spatial data of coastal protected areas and tourism development zones, identify important areas for future research and new marine protection. Our findings show that endemism with its associated risks for Conus in Cape Verde has worldwide parallels with many non-marine taxa, while our proposed strategy for Conus conservation extends beyond the confines of the country and this taxonomic group.
Abstract.
2015
Howarth LM, Roberts CM, Hawkins JP, Steadman DJ, Beukers-Stewart BD (2015). Effects of ecosystem protection on scallop populations within a community-led temperate marine reserve.
Marine Biology,
162(4), 823-840.
Abstract:
Effects of ecosystem protection on scallop populations within a community-led temperate marine reserve
This study investigated the effects of a newly established, fully protected marine reserve on benthic habitats and two commercially valuable species of scallop in Lamlash Bay, Isle of Arran, United Kingdom. Annual dive surveys from 2010 to 2013 showed the abundance of juvenile scallops to be significantly greater within the marine reserve than outside. Generalised linear models revealed this trend to be significantly related to the greater presence of macroalgae and hydroids growing within the boundaries of the reserve. These results suggest that structurally complex habitats growing within the reserve have substantially increased spat settlement and/or survival. The density of adult king scallops declined threefold with increasing distance from the boundaries of the reserve, indicating possible evidence of spillover or reduced fishing effort directly outside and around the marine reserve. However, there was no difference in the mean density of adult scallops between the reserve and outside. Finally, the mean age, size, and reproductive and exploitable biomass of king scallops were all significantly greater within the reserve. In contrast to king scallops, the population dynamics of queen scallops (Aequipecten opercularis) fluctuated randomly over the survey period and showed little difference between the reserve and outside. Overall, this study is consistent with the hypothesis that marine reserves can encourage the recovery of seafloor habitats, which, in turn, can benefit populations of commercially exploited species, emphasising the importance of marine reserves in the ecosystem-based management of fisheries.
Abstract.
Thurstan RH, McClenachan L, Crowder LB, Drew JA, Kittinger JN, Levin PS, Roberts CM, Pandolfi JM (2015). Filling historical data gaps to foster solutions in marine conservation.
Ocean and Coastal Management,
115, 31-40.
Abstract:
Filling historical data gaps to foster solutions in marine conservation
Ecological data sets rarely extend back more than a few decades, limiting our understanding of environmental change and its drivers. Marine historical ecology has played a critical role in filling these data gaps by illuminating the magnitude and rate of ongoing changes in marine ecosystems. Yet despite a growing body of knowledge, historical insights are rarely explicitly incorporated in mainstream conservation and management efforts. Failing to consider historical change can have major implications for conservation, such as the ratcheting down of expectations of ecosystem quality over time, leading to less ambitious targets for recovery or restoration. We discuss several unconventional sources used by historical ecologists to fill data gaps - including menus, newspaper articles, cookbooks, museum collections, artwork, benthic sediment cores - and novel techniques for their analysis. We specify opportunities for the integration of historical data into conservation and management, and highlight the important role that these data can play in filling conservation data gaps and motivating conservation actions. As historical marine ecology research continues to grow as a multidisciplinary enterprise, great opportunities remain to foster direct linkages to conservation and improve the outlook for marine ecosystems.
Abstract.
Peters H, O'Leary BC, Hawkins JP, Roberts CM (2015). Identifying species at extinction risk using global models of anthropogenic impact.
Global Change Biology,
21(2), 618-628.
Abstract:
Identifying species at extinction risk using global models of anthropogenic impact
The International Union for Conservation of Nature Red List of Endangered Species employs a robust, standardized approach to assess extinction threat focussed on taxa approaching an end-point in population decline. Used alone, we argue this enforces a reactive approach to conservation. Species not assessed as threatened but which occur predominantly in areas with high levels of anthropogenic impact may require proactive conservation management to prevent loss. We matched distribution and bathymetric range data from the global Red List assessment of 632 species of marine cone snails with human impacts and projected ocean thermal stress and aragonite saturation (a proxy for ocean acidification). Our results show 67 species categorized as 'Least Concern' have 70% or more of their occupancy in places subject to high and very high levels of human impact with 18 highly restricted species (range
Abstract.
Howarth LM, Pickup SE, Evans LE, Cross TJ, Hawkins JP, Roberts CM, Stewart BD (2015). Sessile and mobile components of a benthic ecosystem display mixed trends within a temperate marine reserve.
Marine Environmental Research,
107, 8-23.
Abstract:
Sessile and mobile components of a benthic ecosystem display mixed trends within a temperate marine reserve
Despite recent efforts to increase the global coverage of marine protected areas (MPAs), studies investigating the effectiveness of marine protected areas within temperate waters remain scarce. Furthermore, out of the few studies published on MPAs in temperate waters, the majority focus on specific ecological or fishery components rather than investigating the ecosystem as a whole. This study therefore investigated the dynamics of both benthic communities and fish populations within a recently established, fully protected marine reserve in Lamlash Bay, Isle of Arran, United Kingdom, over a four year period. A combination of photo and diver surveys revealed live maerl (Phymatolithon calcareum), macroalgae, sponges, hydroids, feather stars and eyelash worms (Myxicola infundibulum) to be significantly more abundant within the marine reserve than on surrounding fishing grounds. Likewise, the overall composition of epifaunal communities in and outside the reserve was significantly different. Both results are consistent with the hypothesis that protecting areas from fishing can encourage seafloor habitats to recover. In addition, the greater abundance of complex habitats within the reserve appeared to providing nursery habitat for juvenile cod (Gadus morhua) and scallops (Pecten maximus and Aequipecten opercularis). In contrast, there was little difference in the abundance of mobile benthic fauna, such as crabs and starfish, between the reserve and outside. Similarly, the use of baited underwater video cameras revealed no difference in the abundance and size of fish between the reserve and outside. Limited recovery of these ecosystem components may be due to the relatively small size (2.67 km2) and young age of the reserve (
Abstract.
Richards K, O'Leary BC, Roberts CM, Ormond R, Gore M, Hawkins JP (2015). Sharks and people: Insight into the global practices of tourism operators and their attitudes to Shark behaviour.
Marine Pollution Bulletin,
91(1), 200-210.
Abstract:
Sharks and people: Insight into the global practices of tourism operators and their attitudes to Shark behaviour
Shark tourism is a popular but controversial activity. We obtained insights into this industry via a global e-mailed questionnaire completed by 45 diving/snorkelling operators who advertised shark experiences (shark operators) and 49 who did not (non-shark operators). 42% of shark operators used an attractant to lure sharks and 93% stated they had a formal code of conduct which 86% enforced "very strictly". While sharks were reported to normally ignore people, 9 operators had experienced troublesome behaviour from them. Whilst our research corroborates previous studies indicating minimal risk to humans from most shark encounters, a precautionary approach to provisioning is required to avoid potential ecological and societal effects of shark tourism. Codes of conduct should always stipulate acceptable diver behaviour and appropriate diver numbers and shark operators should have a moral responsibility to educate their customers about the need for shark conservation.
Abstract.
Sumaila UR, Lam VWY, Miller DD, Teh L, Watson RA, Zeller D, Cheung WWL, Côté IM, Rogers AD, Roberts C, et al (2015). Winners and losers in a world where the high seas is closed to fishing. Scientific Reports, 5(1).
Barrett JH, Locker AM, Roberts CM (2015). ‘Dark Age Economics’ revisited: the English fish bone evidence AD 600-1600. Antiquity, 78(301), 618-636.
2014
Thurstan RH, Hawkins JP, Roberts CM (2014). Origins of the bottom trawling controversy in the British Isles: 19th century witness testimonies reveal evidence of early fishery declines.
Fish and Fisheries,
15(3), 506-522.
Abstract:
Origins of the bottom trawling controversy in the British Isles: 19th century witness testimonies reveal evidence of early fishery declines
Bottom trawling (nets towed along the seabed) spread around the British Isles from the 1820s, yet the collection of national fisheries statistics did not begin until 1886. Consequently, analysis of the impacts of trawling on fish stocks and habitats during this early period is difficult, yet without this information, we risk underestimating the extent of changes that have occurred as a result of trawling activities. We examined witness testimonies recorded during two Royal Commissions of Enquiry (1863-66 and 1883-85). These enquiries interviewed hundreds of fishers about the early effects of sail trawling and the changes they were witnessing to fish stocks, habitats and fishing practises during this time. We converted all quantitative statements of perceived change in fish stocks and fishing practices to relative change. Witnesses from the north-east of England interviewed during 1863 revealed an average perceived decline in whitefish of 64% during their careers, which many blamed upon trawling. Between 1867 and 1892, trawl-landing records from the same location suggest that this trajectory continued, with fish availability declining by 66% during the period. Fishers adapted to these declines by increasing distances travelled to fishing grounds and increasing gear size and quantity. However, inshore declines continued and by the early 1880s even trawl owners were calling for closures of territorial waters to trawling in order to protect fish nursery and spawning grounds. Until now, these testimonies have been largely forgotten, yet they reveal that alterations to near-shore habitats as a result of trawling began long before official data collection was initiated. © 2013 John Wiley & Sons Ltd.
Abstract.
Roberts C, Finkbeiner A, Comfort N, Farmelo G, Gong L, Draaisma D, Catley-Carlson M, Whiteman G, Abdulla S, Baker J, et al (2014). Summer books. Nature, 511(7508), 152-154.
Pimm SL, Jenkins CN, Abell R, Brooks TM, Gittleman JL, Joppa LN, Raven PH, Roberts CM, Sexton JO (2014). The biodiversity of species and their rates of extinction, distribution, and protection.
Science,
344(6187).
Abstract:
The biodiversity of species and their rates of extinction, distribution, and protection
. Background
. A principal function of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is to “perform regular and timely assessments of knowledge on biodiversity.” in December 2013, its second plenary session approved a program to begin a global assessment in 2015. The Convention on Biological Diversity (CBD) and five other biodiversity-related conventions have adopted IPBES as their science-policy interface, so these assessments will be important in evaluating progress toward the CBD’s Aichi Targets of the Strategic Plan for Biodiversity 2011–2020. As a contribution toward such assessment, we review the biodiversity of eukaryote species and their extinction rates, distributions, and protection. We document what we know, how it likely differs from what we do not, and how these differences affect biodiversity statistics. Interestingly, several targets explicitly mention “known species”—a strong, if implicit, statement of incomplete knowledge. We start by asking how many species are known and how many remain undescribed. We then consider by how much human actions inflate extinction rates. Much depends on where species are, because different biomes contain different numbers of species of different susceptibilities. Biomes also suffer different levels of damage and have unequal levels of protection. How extinction rates will change depends on how and where threats expand and whether greater protection counters them.
.
.
. Advances
. Recent studies have clarified where the most vulnerable species live, where and how humanity changes the planet, and how this drives extinctions. These data are increasingly accessible, bringing greater transparency to science and governance. Taxonomic catalogs of plants, terrestrial vertebrates, freshwater fish, and some marine taxa are sufficient to assess their status and the limitations of our knowledge. Most species are undescribed, however. The species we know best have large geographical ranges and are often common within them. Most known species have small ranges, however, and such species are typically newer discoveries. The numbers of known species with very small ranges are increasing quickly, even in well-known taxa. They are geographically concentrated and are disproportionately likely to be threatened or already extinct. We expect unknown species to share these characteristics. Current rates of extinction are about 1000 times the background rate of extinction. These are higher than previously estimated and likely still underestimated. Future rates will depend on many factors and are poised to increase. Finally, although there has been rapid progress in developing protected areas, such efforts are not ecologically representative, nor do they optimally protect biodiversity.
.
.
. Outlook
.
. Progress on assessing biodiversity will emerge from continued expansion of the many recently created online databases, combining them with new global data sources on changing land and ocean use and with increasingly crowdsourced data on species’ distributions. Examples of practical conservation that follow from using combined data in Colombia and Brazil can be found at
. www.savingspecies.org
. and
. www.youtube.com/watch?v=R3zjeJW2NVk
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.
.
Abstract.
Singleton RL, Roberts CM (2014). The contribution of very large marine protected areas to marine conservation: Giant leaps or smoke and mirrors?.
Marine Pollution Bulletin,
87(1), 7-10.
Abstract:
The contribution of very large marine protected areas to marine conservation: Giant leaps or smoke and mirrors?
In recent years, marine protected areas have been "super-sized". At first glance, this seems a gift to marine conservation. Yet, the new wave of very large marine protected areas ("VLMPAs") have faced criticism from the scientific community. In this article we examine the merits and the criticisms of VLMPAS, and consider whether they provide a much-needed boost to marine conservation, or are simply too good to be true.
Abstract.
Thurstan RH, Roberts CM (2014). The past and future of fish consumption: can supplies meet healthy eating recommendations?.
Marine Pollution Bulletin,
89(1-2), 5-11.
Abstract:
The past and future of fish consumption: can supplies meet healthy eating recommendations?
In many developed countries fish and shellfish are increasingly promoted as healthy alternatives to other animal protein. We analysed how much fish was available to UK and global populations after accounting for processing losses, and compared this to recommended levels of fish consumption. In 2012, UK domestic fish landings per capita fell 81% below the recommended intake, although declines were masked by increased imports and aquaculture from the 1970s onwards. Global wild fish supply per capita declined by 32% from its peak in 1970. However, overall fish supplies per capita increased by 10% over the same period due to rapidly expanding aquaculture production. Whilst aquaculture has so far prevented a downturn in global fish supplies, many developed nations continue to aspire to consume more fish than they produce. Until demand is balanced with sustainable methods of production governments should consider carefully the social and environmental implications of greater fish consumption.
Abstract.
Howarth LM, Roberts CM, Thurstan RH, Stewart BD (2014). The unintended consequences of simplifying the sea: Making the case for complexity.
Fish and Fisheries,
15(4), 690-711.
Abstract:
The unintended consequences of simplifying the sea: Making the case for complexity
Many over-exploited marine ecosystems worldwide have lost their natural populations of large predatory finfish and have become dominated by crustaceans and other invertebrates. Controversially, some of these simplified ecosystems have gone on to support highly successful invertebrate fisheries capable of generating more economic value than the fisheries they replaced. Such systems have been compared with those created by modern agriculture on land, in that existing ecosystems have been converted into those that maximize the production of target species. Here, we draw on a number of concepts and case-studies to argue that this is highly risky. In many cases, the loss of large finfish has triggered dramatic ecosystem shifts to states that are both ecologically and economically undesirable, and difficult and expensive to reverse. In addition, we find that those stocks left remaining are unusually prone to collapse from disease, invasion, eutrophication and climate change. We therefore conclude that the transition from multispecies fisheries to simplified invertebrate fisheries is causing a global decline in biodiversity and is threatening global food security, rather than promoting it.
Abstract.
2013
Peters H, O'Leary BC, Hawkins JP, Carpenter KE, Roberts CM (2013). Conus: First comprehensive conservation red list assessment of a marine gastropod mollusc genus.
PLoS ONE,
8(12).
Abstract:
Conus: First comprehensive conservation red list assessment of a marine gastropod mollusc genus
Marine molluscs represent an estimated 23% of all extant marine taxa, but research into their conservation status has so far failed to reflect this importance, with minimal inclusion on the authoritative Red List of the International Union for the Conservation of Nature (IUCN). We assessed the status of all 632 valid species of the tropical marine gastropod mollusc, Conus (cone snails), using Red List standards and procedures to lay the groundwork for future decadal monitoring, one of the first fully comprehensive global assessments of a marine taxon. Three-quarters (75.6%) of species were not currently considered at risk of extinction owing to their wide distribution and perceived abundance. However, 6.5% were considered threatened with extinction with a further 4.1% near threatened. Data deficiency prevented 13.8% of species from being categorised although they also possess characteristics that signal concern. Where hotspots of endemism occur, most notably in the Eastern Atlantic, 42.9% of the 98 species from that biogeographical region were classified as threatened or near threatened with extinction. All 14 species included in the highest categories of Critically Endangered and Endangered are endemic to either Cape Verde or Senegal, with each of the three Critically Endangered species restricted to single islands in Cape Verde. Threats to all these species are driven by habitat loss and anthropogenic disturbance, in particular from urban pollution, tourism and coastal development. Our findings show that levels of extinction risk to which cone snails are exposed are of a similar magnitude to those seen in many fully assessed terrestrial taxa. The widely held view that marine species are less at risk is not upheld. © 2013 Peters et al.
Abstract.
Roberts C (2013). Nature writing: Cetacean subtleties. Nature, 498(7452).
Thurstan RH, Hawkins JP, Raby L, Roberts CM (2013). Oyster (Ostrea edulis) extirpation and ecosystem transformation in the Firth of Forth, Scotland.
Journal for Nature Conservation,
21(5), 253-261.
Abstract:
Oyster (Ostrea edulis) extirpation and ecosystem transformation in the Firth of Forth, Scotland
Marine inshore communities, including biogenic habitats have undergone dramatic changes as a result of exploitation, pollution, land-use changes and introduced species. The Firth of Forth on the east coast of Scotland was once home to the most important oyster (Ostrea edulis Linnaeus, 1758) beds in Scotland. 19th and early 20th century fisheries scientists documented the degradation and loss of these beds, yet transformation of the wider benthic community has been little studied. We undertook archival searches, ecological surveys and shell community analysis using radioisotope dated sediment cores to investigate the history of decline of Forth oyster beds over the last 200 years and the changes to its wider biological communities. Quadrat analysis of the present day benthos reveal that soft-sediment communities dominate the Firth of Forth, with little remaining evidence of past oyster beds in places where abundant shell remains were picked up by a survey undertaken in 1895. Queen scallops (Aequipecten opercularis Linnaeus, 1758) and horse mussels (Modiolus modiolus Linnaeus, 1758) were once common within the Forth but have also markedly decreased compared to the earlier survey. Ouranalyses of shell remains suggest that overall mollusc biomass and species richness declined throughout the 19th century and early 20th century, suggesting broader-scale community change as human impacts increased and as habitats degraded. Inshore communities in the Firth of Forth today are less productive and less diverse compared to past states, with evidence suggesting that most of the damage was done by early bottom trawling and dredging activities. Given the pervasive nature of intensive trawling over the past 150 years, the kind of degradation we document for the Firth of Forth is likely to be commonplace within UK inshore communities. © 2013 Elsevier GmbH.
Abstract.
2012
Thurstan RH, Hawkins JP, Neves L, Roberts CM (2012). Are marine reserves and non-consumptive activities compatible? a global analysis of marine reserve regulations.
Marine Policy,
36(5), 1096-1104.
Abstract:
Are marine reserves and non-consumptive activities compatible? a global analysis of marine reserve regulations
Marine reserves are places where wildlife and habitats are protected from extractive and depositional uses of the sea. Although considered to be the pinnacle in marine conservation, many permit non-consumptive activities with little or no regulation. This paper examines the potential impacts of 16 non-consumptive activities including scuba diving, sailing, scientific research and motor boating, and how they might compromise the conservation objectives of marine reserves. Examination of 91 marine reserves from 36 countries found little agreement or consistency in what non-consumptive activities are permitted in marine reserves and how they are regulated. The two most common activities allowed without regulation were swimming (mentioned in 80% of marine reserves and allowed in 63% of these) and kayaking (mentioned in 85%, allowed in 53%). Scuba diving was mentioned in 91% and allowed without regulation in 41%. A risk score for the likely level of threat to wildlife and/or habitats that each activity could produce was then assigned based on effects reported in the literature. The risk analysis suggests that motor boating and activities which include or require it have a high potential to negatively impact wildlife and habitats if inadequately managed. Hence protection against extractive or depositional activities alone is insufficient to secure the high standard of protection usually assumed in marine reserves. For this to be achieved activities typically considered as benign must receive appropriate management, especially with increasing recreational use. © 2012 Elsevier Ltd.
Abstract.
Veitch L, Dulvy NK, Koldewey H, Lieberman S, Pauly D, Roberts CM, Rogers AD, Baillie JEM (2012). Avoiding Empty Ocean Commitments at Rio+20. Science, 336(6087), 1383-1385.
Roberts C (2012). Marine ecology: Reserves do have a key role in fisheries.
Current Biology,
22(11).
Abstract:
Marine ecology: Reserves do have a key role in fisheries
A new study of the Great Barrier Reef proves a 100-year old conjecture correct: marine reserves do replenish populations in surrounding fishing grounds, while modern reserve networking theory is validated by exchange of offspring of animals among protected areas. © 2012 Elsevier Ltd.
Abstract.
Roberts CM, Reynolds JD, Côté IM, Hawkins JP (2012). Redesigning coral reef conservation. In (Ed) Coral Reef Conservation, Cambridge University Press (CUP), 515-537.
Fox HE, Mascia MB, Basurto X, Costa A, Glew L, Heinemann D, Karrer LB, Lester SE, Lombana AV, Pomeroy RS, et al (2012). Reexamining the science of marine protected areas: Linking knowledge to action.
Conservation Letters,
5(1), 1-10.
Abstract:
Reexamining the science of marine protected areas: Linking knowledge to action
Marine protected areas (MPAs) are often implemented to conserve or restore species, fisheries, habitats, ecosystems, and ecological functions and services; buffer against the ecological effects of climate change; and alleviate poverty in coastal communities. Scientific research provides valuable insights into the social and ecological impacts of MPAs, as well as the factors that shape these impacts, providing useful guidance or "rules of thumb" for science-based MPA policy. Both ecological and social factors foster effective MPAs, including substantial coverage of representative habitats and oceanographic conditions; diverse size and spacing; protection of habitat bottlenecks; participatory decisionmaking arrangements; bounded and contextually appropriate resource use rights; active and accountable monitoring and enforcement systems; and accessible conflict resolution mechanisms. For MPAs to realize their full potential as a tool for ocean governance, further advances in policy-relevant MPA science are required. These research frontiers include MPA impacts on nontarget and wide-ranging species and habitats; impacts beyond MPA boundaries, on ecosystem services, and on resource-dependent human populations, as well as potential scale mismatches of ecosystem service flows. Explicitly treating MPAs as "policy experiments" and employing the tools of impact evaluation holds particular promise as a way for policy-relevant science to inform and advance science-based MPA policy. © 2011 Wiley Periodicals, Inc.
Abstract.
O'Leary BC, Smart JCR, Neale FC, Hawkins JP, Newman S, Milman AC, Datta S, Roberts CM (2012). Response to Cook et al. comment on " Fisheries Mismanagement". Marine Pollution Bulletin, 64(10), 2267-2271.
Hastings J, Thomas S, Burgener V, Gjerde K, Laffoley D, Salm R, McCook L, Pet-Soede L, Eichbaum WM, Bottema M, et al (2012). Safeguarding the blue planet: Six strategies for accelerating ocean protection.
Parks,
18(1), 9-22.
Abstract:
Safeguarding the blue planet: Six strategies for accelerating ocean protection
The oceans are facing greater pressures now than at any other time in human history. Marine protected areas (MPAs), nested within a wider approach of ecosystem-based management, have consistently emerged as one of the most important tools in halting the oceans’ decline and promoting their recovery. The Convention on Biological Diversity (CBD) Aichi Target 11 calls for at least 10 per cent of coastal and marine areas to be conserved through effectively and equitably managed, ecologically representative and well connected systems of protected areas by 2020; unfortunately, most of the Parties are not on track to meet this commitment. To contribute to this effort, this paper details six strategies that can accelerate MPA establishment and create resilient MPA management models around the world. These strategies (build public-private partnerships to change how MPAs are designed and financed; strengthen links between MPAs, local communities and livelihood needs; manage MPAs to enhance carbon stocks and address climate change; act on high seas conservation and initiate MPAs immediately; reframe thinking about the benefits of MPAs; and use technology to connect people with the oceans) can help ensure that the oceans are protected, well managed, and provide livelihood benefits for humanity far into the future.
Abstract.
O'Leary BC, Brown RL, Johnson DE, von Nordheim H, Ardron J, Packeiser T, Roberts CM (2012). The first network of marine protected areas (MPAs) in the high seas: the process, the challenges and where next. Marine Policy, 36(3), 598-605.
2011
Grüss A, Kaplan DM, Guénette S, Roberts CM, Botsford LW (2011). Consequences of adult and juvenile movement for marine protected areas.
Biological Conservation,
144(2), 692-702.
Abstract:
Consequences of adult and juvenile movement for marine protected areas
Adult and juvenile mobility has a considerable influence on the functioning of marine protected areas. It is recognized that adult and juvenile movement reduces the core benefits of protected areas, namely protecting the full age-structure of marine populations, while at the same time perhaps improving fisheries yield over the no-reserve situation through export of individuals from protected areas. Nevertheless, the study of the consequences of movement on protected area functioning is unbalanced. Significant attention has been paid to the influence of certain movement patterns, such as diffusive movement and home ranges, while the impacts of others, such as density-dependent movements and ontogenetic migrations, have been relatively ignored. Here we review the diversity of density-independent and density-dependent movement patterns, as well as what is currently known about their consequences for the conservation and fisheries effects of marine protected areas. We highlight a number of 'partially addressed' issues in marine protected area research, such as the effects of reserves targeting specific life phases, and a number of essentially unstudied issues, such as density-dependent movements, nomadism, ontogenetic migrations, behavioral polymorphism and 'dynamic' reserves that adjust location as a realtime response to habitat changes. Assessing these issues will be essential to creating effective marine protected area networks for mobile species and accurately assessing reserve impacts on these species. © 2010 Elsevier Ltd.
Abstract.
O'Leary BC, Smart JCR, Neale FC, Hawkins JP, Newman S, Milman AC, Roberts CM (2011). Fisheries mismanagement.
Marine Pollution Bulletin,
62(12), 2642-2648.
Abstract:
Fisheries mismanagement
We analysed the extent to which European politicians have adhered to scientific recommendations on annual total allowable catches (TACs) from 1987 to 2011, covering most of the period of the Common Fisheries Policy (CFP). For the 11 stocks examined, TACs were set higher than scientific recommendations in 68% of decisions. Politically-adjusted TACs averaged 33% above scientifically recommended levels. There was no evidence that the 2002 reform of the CFP improved decision-making, as was claimed at the time. We modelled the effects of such politically-driven decision-making on stock sustainability. Our results suggest that political adjustment of scientific recommendations dramatically increases the probability of a stock collapsing within 40. years. In 2012 European fisheries policy will undergo a once-a-decade reform. Ten years ago radical reforms were promised but the changes failed to improve sustainability. It is likely that the 2012 reform will be similarly ineffective unless decision-making is changed so that catch allocations are based on science rather than politics. © 2011 Elsevier Ltd.
Abstract.
O'Leary BC, Roberts C (2011). Fishery reform: ban political haggling. Nature, 475(7357), 454-454.
Barrett JH, Orton D, Johnstone C, Harland J, Van Neer W, Ervynck A, Roberts C, Locker A, Amundsen C, Enghoff IB, et al (2011). Interpreting the expansion of sea fishing in medieval Europe using stable isotope analysis of archaeological cod bones. Journal of Archaeological Science, 38(7), 1516-1524.
Roberts CM, Quinn N, Tucker JW, Woodward PN (2011). Introduction of Hatchery‐Reared Nassau Grouper to a Coral Reef Environment. North American Journal of Fisheries Management, 15(1), 159-164.
2010
Thurstan RH, Roberts CM (2010). Ecological meltdown in the firth of clyde, Scotland: Two centuries of change in a coastal marine ecosystem.
PLoS ONE,
5(7).
Abstract:
Ecological meltdown in the firth of clyde, Scotland: Two centuries of change in a coastal marine ecosystem
Background: the Firth of Clyde is a large inlet of the sea that extends over 100 km into Scotland's west coast. Methods: We compiled detailed fisheries landings data for this area and combined them with historical accounts to build a picture of change due to fishing activity over the last 200 years. Findings: in the early 19th century, prior to the onset of industrial fishing, the Firth of Clyde supported diverse and productive fisheries for species such as herring (Clupea harengus, Clupeidae), cod (Gadus morhua, Gadidae), haddock (Melanogrammus aeglefinus, Gadidae), turbot (Psetta maxima, Scophthalmidae) and flounder (Platichthys flesus, Pleuronectidae). The 19th century saw increased demand for fish, which encouraged more indiscriminate methods of fishing such as bottom trawling. During the 1880s, fish landings began to decline, and upon the recommendation of local fishers and scientists, the Firth of Clyde was closed to large trawling vessels in 1889. This closure remained in place until 1962 when bottom trawling for Norway lobster (Nephrops norvegicus, Nephropidae) was approved in areas more than three nautical miles from the coast. During the 1960s and 1970s, landings of bottomfish increased as trawling intensified. The trawl closure within three nautical miles of the coast was repealed in 1984 under pressure from the industry. Thereafter, bottomfish landings went into terminal decline, with all species collapsing to zero or near zero landings by the early 21st century. Herring fisheries collapsed in the 1970s as more efficient mid-water trawls and fish finders were introduced, while a fishery for mid-water saithe (Pollachius virens, Gadidae) underwent a boom and bust shortly after discovery in the late 1960s. The only commercial fisheries that remain today are for Nephrops and scallops (Pecten maximus, Pectinidae). Significance: the Firth of Clyde is a marine ecosystem nearing the endpoint of overfishing, a time when no species remain that are capable of sustaining commercial catches. The evidence suggests that trawl closures helped maintain productive fisheries through the mid-20th century, and their reopening precipitated collapse of bottomfish stocks. We argue that continued intensive bottom trawling for Nephrops with fine mesh nets will prevent the recovery of other species. This once diverse and highly productive environment will only be restored if trawl closures or other protected areas are re-introduced. The Firth of Clyde represents at a small scale a process that is occurring ocean-wide today, and its experience serves as a warning to others. © 2010 Thurstan, Roberts.
Abstract.
Tickell C, Ormond RFG, Roberts CM (2010). The biodiversity of coral reef fishes. In (Ed) Marine Biodiversity, Cambridge University Press (CUP), 216-257.
Thurstan RH, Brockington S, Roberts CM (2010). The effects of 118 years of industrial fishing on UK bottom trawl fisheries.
Nature Communications,
1(2).
Abstract:
The effects of 118 years of industrial fishing on UK bottom trawl fisheries
In 2009, the European Commission estimated that 88% of monitored marine fish stocks were overfished, on the basis of data that go back 20 to 40 years and depending on the species investigated. However, commercial sea fishing goes back centuries, calling into question the validity of management conclusions drawn from recent data. We compiled statistics of annual demersal fish landings from bottom trawl catches landing in England and Wales dating back to 1889, using previously neglected UK Government data. We then corrected the figures for increases in fishing power over time and a recent shift in the proportion of fish landed abroad to estimate the change in landings per unit of fishing power (LPUP), a measure of the commercial productivity of fisheries. LPUP reduced by 94% - 17-fold - over the past 118 years. This implies an extraordinary decline in the availability of bottom-living fish and a profound reorganization of seabed ecosystems since the nineteenth century industrialization of fishing.
Abstract.
Thurstan RH, Brockington S, Roberts CM (2010). The effects of 118 years of industrial fishing on UK bottom trawl fisheries.
Nature communications,
1Abstract:
The effects of 118 years of industrial fishing on UK bottom trawl fisheries.
In 2009, the European Commission estimated that 88% of monitored marine fish stocks were overfished, on the basis of data that go back 20 to 40 years and depending on the species investigated. However, commercial sea fishing goes back centuries, calling into question the validity of management conclusions drawn from recent data. We compiled statistics of annual demersal fish landings from bottom trawl catches landing in England and Wales dating back to 1889, using previously neglected UK Government data. We then corrected the figures for increases in fishing power over time and a recent shift in the proportion of fish landed abroad to estimate the change in landings per unit of fishing power (LPUP), a measure of the commercial productivity of fisheries. LPUP reduced by 94%-17-fold--over the past 118 years. This implies an extraordinary decline in the availability of bottom-living fish and a profound reorganization of seabed ecosystems since the nineteenth century industrialization of fishing.
Abstract.
2009
Barrett JH, Locker AM, Roberts CM (2009). 'Dark age economics' revisited: the English Fish-bone evidence, 600-1600. In (Ed) Northern World, 31-59.
Roberts CM (2009). Effects of Fishing on the Ecosystem Structure of Coral Reefs. Conservation Biology, 9(5), 988-995.
Price ARG, Roberts CM, Hawkins JP (2009). Recreational Use of Coral Reefs in the Maldives and Caribbean. In (Ed) Conservation of Biological Resources, 242-260.
Barrett JH, Locker AM, Roberts CM (2009). ‘Dark Age Economics’ Revisited: the English Fish-Bone Evidence, 600–1600. In (Ed) Beyond the Catch, Brill Academic Publishers, 29-60.
2008
Sáenz‐Arroyo A, Roberts CM (2008). Consilience in fisheries science. Fish and Fisheries, 9(3), 316-327.
Barrett J, Johnstone C, Harland J, Van Neer W, Ervynck A, Makowiecki D, Heinrich D, Hufthammer AK, Enghoff IB, Amundsen C, et al (2008). Detecting the medieval cod trade: a new method and first results. Journal of Archaeological Science, 35(4), 850-861.
Reynolds JD, Dulvy NK, Roberts CM (2008). Exploitation and Other Threats to Fish Conservation. In (Ed) Handbook of Fish Biology and Fisheries, 319-341.
Gravestock P, Roberts CM, Bailey A (2008). The income requirements of marine protected areas. Ocean & Coastal Management, 51(3), 272-283.
2007
Graham RT, Roberts CM (2007). Assessing the size, growth rate and structure of a seasonal population of whale sharks (Rhincodon typus Smith 1828) using conventional tagging and photo identification. Fisheries Research, 84(1), 71-80.
Barker N, Roberts C (2007). Attitudes to and Preferences of Divers toward Regulation. In (Ed) New Frontiers in Marine Tourism: Diving Experiences, Sustainabilitv, Management, 171-188.
Barker N, Roberts C (2007). Attitudes to and preferences of divers toward regulation. In (Ed) New Frontiers in Marine Tourism, 171-187.
Mallela J, Roberts C, Harrod C, Goldspink CR (2007). Distributional patterns and community structure of Caribbean coral reef fishes within a river-impacted bay.
Journal of Fish Biology,
70(2), 523-537.
Abstract:
Distributional patterns and community structure of Caribbean coral reef fishes within a river-impacted bay
This study examined how riverine inputs, in particular sediment, influenced the community structure and trophic composition of reef fishes within Rio Bueno, north Jamaica. Due to river discharge a distinct gradient of riverine inputs existed across the study sites. Results suggested that riverine inputs (or a factor associated with them) had a structuring effect on fish community structure. Whilst fish communities at all sites were dominated by small individuals (
Abstract.
Hawkins JP, Roberts CM, Gell FR, Dytham C (2007). Effects of trap fishing on reef fish communities.
Aquatic Conservation: Marine and Freshwater Ecosystems,
17(2), 111-132.
Abstract:
Effects of trap fishing on reef fish communities
1. Trap fishing is widespread on coral reefs but the sustainability of this practice is causing concern because it is efficient and unselective. The effects of trap fishing were investigated by comparing fish assemblages among six Caribbean islands subject to different trapping pressures. These ranged from none in Bonaire and Saba increasing through Puerto Rico, St Lucia, Dominica and Jamaica respectively. 2. Fish were censused at depths of 5 m and 15 m on fore-reef slopes by counting the numbers within replicate 10 m diameter areas for 15 min. Between 64 and 1375 counts were made in each country. 3. In St Lucia and Jamaica abundance of fish censused on the reef was compared to representation in traps which were visually sampled underwater in the area of fish counts. Twenty-three traps were sampled in Jamaica and 75 in St Lucia. For some comparisons between these islands, St Lucian sampling effort was reduced to that of Jamaica (23 traps and 112 counts) by randomly sub-sampling 10 times. 4. Traps contained 54 different species in St Lucia and 22 in Jamaica, while there were 90 and 57 respectively in counts. After reducing St Lucian sampling effort to Jamaican levels, an average of 35 species were found in traps and 70 seen in counts. of these, 76% in St Lucia and 73% in Jamaica were relatively more abundant in traps than they were on the reef. 5. Species were considered to be highly susceptible to trapping if the ratio of their abundance in traps compared to that on the reef exceeded 3:1. Trapping pressure was approximately three and a half times greater in Jamaica than St Lucia. After equalizing sampling effort, there was an average of 16 highly trappable species in St Lucia compared to 13 in Jamaica. Species did not always appear highly trappable in both countries. Eleven of St Lucia's highly trappable species were absent from Jamaica (falling to 8.5 on average after equalizing sampling effort), but none vice versa, suggesting that trapping may have contributed to their absence or rarity on Jamaican reefs. 6. The Tetraodontiformes, which include many non-target species, were particularly susceptible to trapping in both countries. Their abundance in the six islands censused was inversely related to trap fishing pressure, as was that of two other non-target families, butterflyfish (Chaetodontidae) and angelfish (Pomacanthidae). 7. To determine whether fish that are common in traps in St Lucia are reaching sexual maturity before capture, size frequency data for 23 species from a sample of trap catches were gathered and examined for their state of maturity. In seven species, more than a third of 705 trapped fish were immature, indicating that trap fishing causes growth over-fishing (premature removal of fish), and calling into question the sustainability of yields for these species. 8. In conclusion, at the intensities seen in this study, trap fisheries cause serious over-fishing, reduce biodiversity, and alter ecosystem structure. While commonly perceived as low impact, coral reef trap fisheries in the Caribbean and further afield, need tighter regulation and control. Copyright © 2006 John Wiley & Sons, Ltd.
Abstract.
Mangi SC, Roberts CM (2007). Factors influencing fish catch levels on Kenya's coral reefs. Fisheries Management and Ecology, 14(4), 245-253.
Roberts C (2007). Faith, evolution, and the burden of proof [2]. Fisheries, 32(2).
Mangi SC, Roberts CM, Rodwell LD (2007). Financial Comparisons of Fishing Gear Used in Kenya's Coral Reef Lagoons. Ambio, 36(8), 671-676.
Graham RT, Carcamo R, Rhodes KL, Roberts CM, Requena N (2007). Historical and contemporary evidence of a mutton snapper (Lutjanus analis Cuvier, 1828) spawning aggregation fishery in decline. Coral Reefs, 27(2), 311-319.
Mangi SC, Roberts CM, Rodwell LD (2007). Reef fisheries management in Kenya: Preliminary approach using the driver–pressure–state–impacts–response (DPSIR) scheme of indicators. Ocean & Coastal Management, 50(5-6), 463-480.
2006
Roberts CM, Halpern B, Palumbi SR, Warner RR (2006). Designing Marine Reserve Networks Why Small, Isolated Protected Areas Are Not Enough. Conservation, 2(3), 10-17.
Hawkins JP, Roberts CM, Dytham C, Schelten C, Nugues MM (2006). Effects of habitat characteristics and sedimentation on performance of marine reserves in St. Lucia.
Biological Conservation,
127(4), 487-499.
Abstract:
Effects of habitat characteristics and sedimentation on performance of marine reserves in St. Lucia
This study examines factors affecting the rate and extent of biomass build-up among commercially important groupers, snappers, grunts, parrotfish and surgeonfish in a network of four marine reserves in southwest St. Lucia, Caribbean. Reserves constituted 35% of the total reef area originally available for fishing. Protection was instigated in 1995 after a baseline survey with annual or biennial censuses performed until 2002. Each survey consisted of 114 fifteen minute fish counts in reserves and 83 in fishing grounds, at depths of 5 m and 15 m in a 10 m diameter counting area. Estimates of number and size (cm) of target species were used to calculate fish family biomass. Data were analysed using three-way ANOVA in a before-after-control-impact pairs (BACIP) design. All families increased significantly in biomass over time at nearly all sites. Increases were greater in reserves than fishing grounds, except for grunts, and responses were strongest in parrotfish and surgeonfish. The combined biomass of families more than quadrupled in reserves and tripled in fishing grounds between 1995 and 2002. During this period coral cover declined by 46% in reserves and 35% in fishing grounds. Multiple regression showed that neither habitat characteristics nor habitat deterioration significantly affected rates of biomass build-up. The key factor was protection from fishing, which explained 44% of the variance in biomass growth. A further 28% of the variance was explained by sedimentation, a process known to stress reef invertebrates, significantly reducing the rate of biomass build-up. St. Lucia's reserves succeeded in producing significant gains to fish stocks despite coral cover and structural complexity falling steeply over the period of the study. © 2005 Elsevier Ltd. All rights reserved.
Abstract.
Mangi SC, Roberts CM (2006). Quantifying the environmental impacts of artisanal fishing gear on Kenya’s coral reef ecosystems. Marine Pollution Bulletin, 52(12), 1646-1660.
Rodwell LD, Roberts CM (2006). Reply to the comment by Holland and Stokes on "Fishing and the impact of marine reserves in a variable environment". Canadian Journal of Fisheries and Aquatic Sciences, 63(5), 1186-1188.
Sáenz-Arroyo A, Roberts CM, Torre J, Cariño-Olvera M, Hawkins JP (2006). The value of evidence about past abundance: Marine fauna of the Gulf of California through the eyes of 16th to 19th century travellers.
Fish and Fisheries,
7(2), 128-146.
Abstract:
The value of evidence about past abundance: Marine fauna of the Gulf of California through the eyes of 16th to 19th century travellers
Eyewitness accounts written by early travellers to 'the new worlds' provide valuable insights into how seascapes once looked. Although this kind of information has been widely used to chart human impacts on terrestrial ecosystems, it has been greatly overlooked in the marine realm. Here we present a synthesis of 16th to 19th century travellers' descriptions of the Gulf of California and its marine wildlife. The diaries written by conquerors, pirates, missionaries and naturalists described a place in which whales were 'innumerable,' turtles were 'covering the sea' and large fish were so abundant that they could be taken by hand. Beds of pearl oysters that are described had disappeared by 1940 and only historical documents reveal the existence of large, widespread, deep pearl oyster reefs, whose ecology and past functions we know little about. Disqualifying the testimonies of early visitors to a region as 'anecdotal' is dangerous; it may lead to setting inappropriate management targets that could lead to the extinction of species that are rare today but were once much more abundant. Moreover, it represents unfair historical judgement on the work of early natural historians, scholars and scientists. We suggest that the review and analytical synthesis of reports made by early travellers should become part of the pre-requisites for deciding how to manage marine ecosystems today. © 2006 Blackwell Publishing Ltd.
Abstract.
2005
Graham RT, Roberts CM, Smart JCR (2005). Diving behaviour of whale sharks in relation to a predictable food pulse. Journal of the Royal Society Interface, 3(6), 109-116.
Senz-Arroyo A, Roberts C, Torre J, Cario-Olvera M, Enrquez-Andrade R (2005). Rapidly shifting environmental baselines among fishers of the Gulf of California. Proceedings of the Royal Society B, 272(1575), 1957-1962.
Hawkins JP, Roberts CM, Kooistra D, Buchan K, White S (2005). Sustainability of scuba diving tourism on coral reefs of Saba.
Coastal Management,
33(4), 373-387.
Abstract:
Sustainability of scuba diving tourism on coral reefs of Saba
We examine the effects of recreational scuba diving in the Saba Marine Park in the Netherlands Antilles over a nine-year period. Levels of diving have remained low whereas dive fees have provided a major source of income to this park. We studied 5 dive sites where the average number of dives per site per year ranged from 445 to 2,163. At each site we recorded benthic parameters and levels of damage within at least 25 randomly placed quadrats in areas designated to be High use (0-20 m from mooring) or Low use (40-60 m from moorings), at yearly or biennial intervals. Within the same dive site, there was significantly more broken coral and fragments of live coral in High use areas than Low use. However, across sites, damage was not significantly related to diving intensity and nor did it accumulate over time. The Saba Marine Park shows that it is possible to fund protection at sustainable levels of use. Copyright © Taylor & Francis Inc.
Abstract.
Roberts CM, Hawkins JP, Gell FR (2005). The role of marine reserves in achieving sustainable fisheries.
Philosophical Transactions of the Royal Society B: Biological Sciences,
360(1453), 123-132.
Abstract:
The role of marine reserves in achieving sustainable fisheries
Many fishery management tools currently in use have conservation value. They are designed to maintain stocks of commercially important species above target levels. However, their limitations are evident from continuing declines in fish stocks throughout the world. We make the case that to reverse fishery declines, safeguard marine life and sustain ecosystem processes, extensive marine reserves that are off limits to fishing must become part of the management strategy. Marine reserves should be incorporated into modern fishery management because they can achieve many things that conventional tools cannot. Only complete and permanent protection from fishing can protect the most sensitive habitats and vulnerable species. Only reserves will allow the development of natural, extended age structures of target species, maintain their genetic variability and prevent deleterious evolutionary change from the effects of fishing. Species with natural age structures will sustain higher rates of reproduction and will be more resilient to environmental variability. Higher stock levels maintained by reserves will provide insurance against management failure, including risk-prone quota setting, provided the broader conservation role of reserves is firmly established and legislatively protected. Fishery management measures outside protected areas are necessary to complement the protection offered by marine reserves, but cannot substitute for it. © 2005 the Royal Society.
Abstract.
Sáenz–Arroyo A, Roberts CM, Torre J, Cariño‐Olvera M (2005). Using fishers’ anecdotes, naturalists’ observations and grey literature to reassess marine species at risk: the case of the Gulf grouper in the Gulf of California, Mexico. Fish and Fisheries, 6(2), 121-133.
2004
Roberts CM (2004). Advocating against advocacy in fisheries management Fisheries Ecology and Management by Carl J. Walters and Steven J.D. Martell. Princeton University Press, 2004. US$99.50/US$45.00 hbk/pbk (448 pages) ISBN 0 691 11544 3. Trends in Ecology & Evolution, 19(9), 462-463.
Hawkins JP, Roberts CM (2004). Effects of Artisanal Fishing on Caribbean Coral Reefs.
Conservation Biology,
18(1), 215-226.
Abstract:
Effects of Artisanal Fishing on Caribbean Coral Reefs
Although the impacts of industrial fishing are widely recognized, marine ecosystems are generally considered less threatened by artisanal fisheries. To determine how coral reef fish assemblages and benthic communities are affected by artisanal fishing, we studied six Caribbean islands on which fishing pressure ranged from virtually none in Bonaire, increasing through Saba, Puerto Rico, St Lucia, and Dominica, and reaching very high intensities in Jamaica. Using stationary-point fish counts at 5 m and 15 m depth, we counted and estimated the lengths of all noncryptic, diurnal fish species within replicate 10-m-diameter areas. We estimated percent cover of coral and algae and determined reef structural complexity. From fish numbers and lengths we calculated mean fish biomass per count for the five most commercially important families. Groupers (Serranidae), snappers (Lutjanidae), parrotfish (Scaridae), and surgeonfish (Acanthuridae) showed order-of-magnitude differences in biomass among islands. Biomass fell as fishing pressure increased. Only grunts (Haemulidae) did not follow this pattern. Within families, larger-bodied species decreased as fishing intensified. Coral cover and structural complexity were highest on little-fished islands and lowest on those most fished. By contrast, algal cover was an order of magnitude higher in Jamaica than in Bonaire. These results suggest that following the Caribbean-wide mass mortality of herbivorous sea urchins in 1983-1984 and consequent declines in grazing pressure on reefs, herbivorous fishes have not controlled algae overgrowing corals in heavily fished areas but have restricted growth in lightly fished areas. In summary, differences among islands in the structure offish and benthic assemblages suggest that intensive artisanal fishing has transformed Caribbean reefs.
Abstract.
Hawkins JP, Roberts CM (2004). Effects of fishing on sex-changing Caribbean parrotfishes.
Biological Conservation,
115(2), 213-226.
Abstract:
Effects of fishing on sex-changing Caribbean parrotfishes
We studied parrotfish (Scaridae) assemblages on coral reefs in relation to fishing pressure around six Caribbean islands. Fishing intensity ranged from virtually none in Bonaire, and increased through Saba, Puerto Rico, St Lucia and Dominica to extremely high levels in Jamaica. In St Lucia we also compared parrotfish assemblages between fishing grounds and fully protected marine reserves, from 1995, 6 months prior to establishment, to 2001. Within each country we performed replicate counts of the number and size of all parrotfish species within, or passing through our counting area. From these data we calculated biomass for seven species. Biomass of the two largest species, Sparisoma viride and Scarus vetula, was greatest in islands with low fishing pressure (P < 0.001). By contrast, smaller species constituted an increasing proportion of the total parrotfish assemblage as fishing pressure increased (P < 0.001 in all cases). Parrotfish are protogynous hermaphrodites with two distinct colour phases. The initial phase is predominantly female, and the terminal phase exclusive to sexually mature males. The average size of all species except Sc. vetula tended to decrease with increasing fishing pressure. Furthermore, percentages of fish that were terminal phase males showed order of magnitude declines with increasing fishing pressure for Sp. viride and Sc. vetula. Terminal males of these species were absent from counts in Jamaica and virtually absent from Dominica suggesting that persistence of these populations may depend on recruitment from distant sources. Following reserve implementation in St Lucia, all species, except uncommon Sp. chrysopterum, increased in mean biomass (P < 0.001 in all cases). In 6 years the total biomass for all species combined increased to become nearly four times as high in reserves and almost twice as high in fishing grounds [P < 0.001 (year effect); P < 0.001 (protection effect); P < 0.001 (yearxprotection)], and mean size of five species increased significantly in both reserves and fishing grounds. © 2003 Elsevier Ltd. All rights reserved.
Abstract.
Rodwell LD, Roberts CM (2004). Fishing and the impact of marine reserves in a variable environment.
Canadian Journal of Fisheries and Aquatic Sciences,
61(11), 2053-2068.
Abstract:
Fishing and the impact of marine reserves in a variable environment
We use discrete-time models to investigate the impact of marine reserve establishment on fishery catch and biomass levels in open-access and quota-regulated fisheries under conditions of recruitment variability and natural mortality events. We find that under the conditions of variability tested, reserves can increase the probability of achieving target levels of biomass (60%, 35%, and 5% of carrying capacity) and can reduce catch variability in neighbouring fisheries, making future planning in the fishery more efficient. The size of the reserve required to meet each objective will depend on the initial condition of the stock and the exploitation rate in the fishery. Reserve coverage of between 20% and 40% prevent stock collapse in most cases. In heavily exploited fisheries, reserves are also likely to enhance mean catches, particularly in highly variable systems. If the stock has previously been heavily exploited, large reserves (≥60%) may be required to significantly increase the probability of achieving target biomass levels. However, once stocks have recovered, reserve coverage may be reduced without a reduction in this probability of success. © 2004 NRC Canada.
Abstract.
Duda TF, Bingham JP, Livett BG, Kohn AJ, Massilia GR, Schultz JR, Down J, Sandall D, Sweedler JV, Fainzilber M, et al (2004). How Much at Risk Are Cone Snails? [3] (multiple letters). Science, 303(5660), 955-957.
Barker NHL, Roberts CM (2004). Scuba diver behaviour and the management of diving impacts on coral reefs.
Biological Conservation,
120(4), 481-489.
Abstract:
Scuba diver behaviour and the management of diving impacts on coral reefs
Coral reefs worldwide are attracting increasing numbers of scuba divers, leading to growing concern about damage. There is now a need to manage diver behaviour closely, especially as many dive companies offer unlimited, unsupervised day and night diving from shore. We observed 353 divers in St. Lucia and noted all their contacts with the reef during entire dives to quantify rates of damage and seek ways of reducing it. Divers using a camera caused significantly more contacts with the reef than did those without cameras (mean 0.4 versus 0.1 contacts min -1), as did shore versus boat dives (mean 0.5 versus 0.2 contacts min -1) and night versus day dives (mean 1.0 versus 0.4 contacts min -1). We tested the effect of a one-sentence inclusion in a regular dive briefing given by local staff that asked divers to avoid touching the reef. We also examined the effect of dive leader intervention on rates of diver contact with the reef. Briefing alone had no effect on diver contact rates, or on the probability of a diver breaking living substrate. However, dive leader intervention when a diver was seen to touch the reef reduced mean contact rates from 0.3 to 0.1 contacts min -1 for both shore and boat dives, and from 0.2 to 0.1 contacts min -1 for boat dives. Given that briefings alone are insufficient to reduce diver damage, we suggest that divers need close supervision, and that dive leaders must manage diver behaviour in situ. © 2004 Elsevier Ltd. All rights reserved.
Abstract.
Barrett JH, Locker AM, Roberts CM (2004). The origins of intensive marine fishing in medieval Europe: the English evidence. Proceedings of the Royal Society B, 271(1556), 2417-2421.
Balmford A, Gravestock P, Hockley N, McClean CJ, Roberts CM (2004). The worldwide costs of marine protected areas. Proceedings of the National Academy of Sciences of the United States of America, 101(26), 9694-9697.
2003
Roberts CM, Branch G, Bustamante RH, Castilla JC, Dugan J, Halpern BS, Lafferty KD, Leslie H, Lubchenco J, McArdle D, et al (2003). Application of ecological criteria in selecting marine reserves and developing reserve networks.
Ecological Applications,
13(1 SUPPL.).
Abstract:
Application of ecological criteria in selecting marine reserves and developing reserve networks
Marine reserves are being established worldwide in response to a growing recognition of the conservation crisis that is building in the oceans. However, designation of reserves has been largely opportunistic, or protective measures have been implemented (often overlapping and sometimes in conflict) by different entities seeking to achieve different ends. This has created confusion among both users and enforcers, and the proliferation of different measures provides a false sense of protection where little is offered. This paper sets out a procedure grounded in current understanding of ecological processes, that allows the evaluation and selection of reserve sites in order to develop functional, interconnected networks of fully protected reserves that will fulfill multiple objectives. By fully protected we mean permanently closed to fishing and other resource extraction. We provide a framework that unifies the central aims of conservation and fishery management, while also meeting other human needs such as the provision of ecosystem services (e.g. maintenance of coastal water quality, shoreline protection, and recreational opportunities). In our scheme, candidate sites for reserves are evaluated against 12 criteria focused toward sustaining the biological integrity and productivity of marine systems at both local and regional scales. While a limited number of sites will be indispensable in a network, many will be of similar value as reserves, allowing the design of numerous alternative, biologically adequate networks. Devising multiple network designs will help ensure that ecological functionality is preserved throughout the socioeconomic evaluation process. Too often, socioeconomic criteria have dominated the process of reserve selection, potentially undermining their efficacy. We argue that application of biological criteria must precede and inform socioeconomic evaluation, since maintenance of ecosystem functioning is essential for meeting all of the goals for reserves. It is critical that stakeholders are fully involved throughout this process. Application of the proposed criteria will lead to networks whose multifunctionality will help unite the objectives of different management entities, so accelerating progress toward improved stewardship of the oceans.
Abstract.
Gell FR, Roberts CM (2003). Benefits beyond boundaries: the fishery effects of marine reserves.
Trends in Ecology and Evolution,
18(9), 448-455.
Abstract:
Benefits beyond boundaries: the fishery effects of marine reserves
Marine reserves are areas of the sea where fishing is not allowed. They provide refuges where populations of exploited species can recover and habitats modified by fishing can regenerate. In some places, closed areas have been used for fisheries management for centuries [1] and, until recently, natural refugia also existed, inaccessible through depth, distance or adverse conditions. Developments in technology have left few areas of fishing interest beyond our reach. Recently, the idea of marine reserves as fisheries management tools has re-emerged with developing interest in ecosystem-based management, and observations of incidental fisheries benefits from reserves established for conservation. In light of new evidence, we argue that, by integrating large-scale networks of marine reserves into fishery management, we could reverse global fishery declines and provide urgently needed protection for marine species and their habitats.
Abstract.
Nugues MM, Roberts CM (2003). Coral mortality and interaction with algae in relation to sedimentation.
Abstract:
Coral mortality and interaction with algae in relation to sedimentation
Abstract.
Roberts CM, Andelman S, Branch G, Bustamante RH, Castilla JC, Dugan J, Halpern BS, Lafferty KD, Leslie H, Lubchenco J, et al (2003). ECOLOGICAL CRITERIA FOR EVALUATING CANDIDATE SITES FOR MARINE RESERVES. Ecological Applications, 13(sp1), 199-214.
Roberts CM, Andelman S, Branch G, Bustamante RH, Castilla JC, Dugan J, Halpern BS, Lafferty KD, Leslie H, Lubchenco J, et al (2003). Ecological criteria for evaluating candidate sites for marine reserves.
Ecological Applications,
13(1 SUPPL.).
Abstract:
Ecological criteria for evaluating candidate sites for marine reserves
Several schemes have been developed to help select the locations of marine reserves. All of them combine social, economic, and biological criteria, and few offer any guidance as to how to prioritize among the criteria identified. This can imply that the relative weights given to different criteria are unimportant. Where two sites are of equal value ecologically, then socioeconomic criteria should dominate the choice of which should be protected. However, in many cases, socioeconomic criteria are given equal or greater weight than ecological considerations in the choice of sites. This can lead to selection of reserves with little biological value that fail to meet many of the desired objectives. To avoid such a possibility, we develop a series of criteria that allow preliminary evaluation of candidate sites according to their relative biological values in advance of the application of socioeconomic criteria. We include criteria that, while not strictly biological, have a strong influence on the species present or ecological processes. Our scheme enables sites to be assessed according to their biodiversity, the processes which underpin that diversity, and the processes that support fisheries and provide a spectrum of other services important to people. Criteria that capture biodiversity values include biogeographic representation, habitat representation and heterogeneity, and presence of species or populations of special interest (e.g. threatened species). Criteria that capture sustainability of biodiversity and fishery values include the size of reserves necessary to protect viable habitats, presence of exploitable species, vulnerable life stages, connectivity among reserves, links among ecosystems, and provision of ecosystem services to people. Criteria measuring human and natural threats enable candidate sites to be eliminated from consideration if risks are too great, but also help prioritize among sites where threats can be mitigated by protection. While our criteria can be applied to the design of reserve networks, they also enable choice of single reserves to be made in the context of the attributes of existing protected areas. The overall goal of our scheme is to promote the development of reserve networks that will maintain biodiversity and ecosystem functioning at large scales. The values of ecosystem goods and services for people ultimately depend on meeting this objective.
Abstract.
Roberts CM (2003). Our shifting perspectives on the oceans. Oryx, 37(2), 166-177.
Nugues MM, Roberts CM (2003). Partial mortality in massive reef corals as an indicator of sediment stress on coral reefs. Marine Pollution Bulletin, 46(3), 314-323.
Chivian E, Roberts CM, Bernstein AS (2003). The Threat to Cone Snails. Science, 302(5644), 391-391.
Rodwell LD, Barbier EB, Roberts CM, McClanahan TR (2003). The importance of habitat quality for marine reserve – fishery linkages. Canadian Journal of Fisheries and Aquatic Sciences, 60(2), 171-181.
Milner-Gulland EJ, Bennett EL, Abernethy K, Bakarr M, Bennett E, Bodmer R, Brashares J, Cowlishaw G, Elkan P, Eves H, et al (2003). Wild meat: the bigger picture.
Trends in Ecology and Evolution,
18(7), 351-357.
Abstract:
Wild meat: the bigger picture
Massive overhunting of wildlife for meat across the humid tropics is now causing local extinctions of numerous species. Rural people often rely heavily on wild meat, but, in many areas, this important source of food and income is either already lost or is being rapidly depleted. The problem can only be tackled by looking at the wider economic and institutional context within which such hunting occurs, from household economics to global terms of trade. Conservation efforts must be placed within a landscape context; a mosaic of hunted and no-take areas might balance conservation with continued subsistence use. Successful conservation of hunted wildlife requires collaboration at all scales, involving local people, resource extraction companies, governments and scientists.
Abstract.
2002
Rodwell LD, Barbier EB, Roberts CM, McCLanahan TR (2002). A model of tropical marine reserve-fishery linkages.
Natural Resource Modeling,
15(4), 453-486.
Abstract:
A model of tropical marine reserve-fishery linkages
The excessive and unsustainable exploitation of our marine resources has led to the promotion of marine reserves as a fisheries management tool. Marine reserves, areas in which fishing is restricted or prohibited, can offer opportunities for the recovery of exploited stock and fishery enhancement. In this paper we examine the contribution of fully protected tropical marine reserves to fishery enhancement by modeling marine reserve-fishery linkages. The consequences of reserve establishment on the long-run equilibrium fish biomass and fishery catch levels are evaluated. In contrast to earlier models this study highlights the roles of both adult (and juvenile) fish migration and larval dispersal between the reserve and fishing grounds by employing a spawner-recruit model. Uniform larval dispersal, uniform larval retention and complete larval retention combined with zero, moderate and high fish migration scenarios are analyzed in turn. The numerical simulations are based on Mombasa Marine National Park, Kenya, a fully protected coral reef marine reserve comprising approximately 30% of former fishing grounds. Simulation results suggest that the establishment of a fully protected marine reserve will always lead to an increase in total fish biomass. If the fishery is moderately to heavily exploited, total fishery catch will be greater with the reserve in all scenarios of fish and larval movement. If the fishery faces low levels of exploitation, catches can be optimized without a reserve but with controlled fishing effort. With high fish migration from the reserve, catches are optimized with the reserve. The optimal area of the marine reserve depends on the exploitation rate in the neighboring fishing grounds. For example, if exploitation is maintained at 40%, the ‘optimal’ reserve size would be 10%. If the rate increases to 50%, then the reserve needs to be 30% of the management area in order to maximize catches. However, even in lower exploitation fisheries (below 40%), a small reserve (up to 20%) provides significantly higher gains in fish biomass than losses in catch. Marine reserves are a valuable fisheries management tool. To achieve maximum fishery benefits they should be complemented by fishing effort controls. © 2002 Rocky Mountain Mathematics Consortium.
Abstract.
Baird AH, Bellwood DR, Connell JH, Cornell HV, Hughes TP, Karlson RH, Rosen BR, Briggs JC, Roberts CM, McClean CJ, et al (2002). Coral reef biodiversity and conservation [2] (multiple letters). Science, 296(5570), 1026-1028.
Roberts CM (2002). Deep impact: the rising toll of fishing in the deep sea.
Trends in Ecology and Evolution,
17(5), 242-245.
Abstract:
Deep impact: the rising toll of fishing in the deep sea
The deep ocean is one of the last great wildernesses. Waters deeper than 1000 m cover an estimated 62% of the planet. In spite of more than 150 years of exploration, the ocean depths remain virtually unknown. Biological science has so far touched upon only one millionth of the deep-sea floor, but new technology is revealing unknown and exotic habitats as quickly as we look. Those technologies are also bringing the deep within reach of industry, with devastating consequences.
Abstract.
Roberts CM, Sargant H (2002). Fishery benefits of fully protected marine reserves: Why habitat and behavior are important.
Natural Resource Modeling,
15(4), 487-507.
Abstract:
Fishery benefits of fully protected marine reserves: Why habitat and behavior are important
Fully protected marine reserves, areas that are closed to all fishing, have attracted great interest for their potential to benefit fisheries. A wide range of models suggest reserves will be most effective for species that are relatively sedentary as adults but produce offspring that disperse widely. Adult spawning stocks will be secure from capture in reserves, while their offspring disperse freely into fishing grounds. Such species include animals like reef fish, mollusks and echino-derms, and models typically indicate that when they are over-fished, catches will be higher with reserves than without. By contrast, the same models suggest that reserves will be ineffective for animals that are mobile as adults species like cod, tuna or sharks. They remain vulnerable to fishing whenever they move outside reserves. Unfortunately, most models lack sufficient realism to effectively gauge reserve effects on migratory species. They usually assume that individuals are homogeneously distributed in a uniform sea and move randomly. They also assume that fishers hunt at random. Neither is true. For centuries, fishers have targeted places and times when their quarry are most vulnerable to capture. Protecting these sites could have disproportionately large effects on stocks. Furthermore, models rarely take into account possible benefits from improvements in habitat within reserves. Such changes, like increased biomass and complexity of bottom-living organisms, could alter fish movement patterns and reduce natural mortality rates in ways that enhance reserve benefits. We present a simple model of reserve effects on a migratory fish species. The model incorporates spatial variation in vulnerability to capture and shows that strategically placed reserves can offer benefits in the form of increased spawning stock and catch, especially when fishing intensities are high. We need to develop a new generation of models that incorporate habitat and behaviour to better explore the utility of reserves for mobile species. Migratory behavior does not preclude reserves from benefiting a species, but it demands that we apply different principles in designing them. We must identify critical sites to species and develop reserve networks that focus protection on those places. © 2002 Rocky Mountain Mathematics Consortium.
Abstract.
Roberts CM, McClean CJ, Veron JEN, Hawkins JP, Allen GR, McAllister DE, Mittermeier CG, Schueler FW, Spalding M, Wells F, et al (2002). Marine biodiversity hotspots and conservation priorities for tropical reefs.
Science,
295(5558), 1280-1284.
Abstract:
Marine biodiversity hotspots and conservation priorities for tropical reefs
Coral reefs are the most biologically diverse of shallow water marine ecosystems but are being degraded worldwide by human activities and climate warming. Analyses of the geographic ranges of 3235 species of reef fish, corals, snails, and lobsters revealed that between 7.2% and 53.6% of each taxon have highly restricted ranges, rendering them vulnerable to extinction. Restricted-range species are clustered into centers of endemism, like those described for terrestrial taxa. The 10 richest centers of endemism cover 15.8% of the world's coral reefs (0.012% of the oceans) but include between 44.8 and 54.2% of the restricted-range species. Many occur in regions where reefs are being severely affected by people, potentially leading to numerous extinctions. Threatened centers of endemism are major biodiversity hotspots, and conservation efforts targeted toward them could help avert the loss of tropical reef biodiversity.
Abstract.
Tupper MH, Wickstrom K, Hilborn R, Roberts CM, Bohnsack JA, Gell F, Hawkins JP, Goodridge R (2002). Marine reserves and fisheries management. Science, 295(5558), 1233-1235.
Roberts CM (2002). Rapid Build‐up of Fish Biomass in a Caribbean Marine Reserve. Conservation Biology, 9(4), 815-826.
2001
Pimm SL, Ayres M, Balmford A, Branch G, Brandon K, Brooks T, Bustamante R, Costanza R, Cowling R, Curran LM, et al (2001). Can We Defy Nature's End?. Science, 293(5538), 2207-2208.
Roberts CM, Bohnsack JA, Gell F, Hawkins JP, Goodridge R (2001). Effects of marine reserves on adjacent fisheries.
SCIENCE,
294(5548), 1920-1923.
Author URL.
Roberts CM, Ormsby A, Tschirhart J, Berger J, O’Hara JL, Johns D, Reid WV (2001). Emptying the Oceans of Fish. Conservation Biology, 13(1), 216-222.
Roberts CM (2001). What is Natural? Coral Reef Crisis J. Sapp; Oxford University Press, New York, 1999, 275 pages, hardback, ISBN 0-19-512364-6, £22.50 (US$30). Biological Conservation, 98(3), 381-385.
2000
Pezzey JCV, Roberts CM, Urdal BT (2000). A simple bioeconomic model of a marine reserve. Ecological Economics, 33(1), 77-91.
Roberts CM (2000). Selecting marine reserve locations: Optimality versus opportunism.
Abstract:
Selecting marine reserve locations: Optimality versus opportunism
Abstract.
Morris AV, Roberts CM, Hawkins JP (2000). The threatened status of groupers (Epinephelinae).
Biodiversity and Conservation,
9(7), 919-942.
Abstract:
The threatened status of groupers (Epinephelinae)
The marine environment has traditionally been considered to be resilient to human impacts. However, concern over growing threats to marine biodiversity has led to a renewed effort to assess and quantify risks to marine species. This study assesses threats to the subfamily Epinephelinae of the Serranidae (groupers), a commercially and ecologically important group of predatory fish which are heavily exploited throughout their range. Eighty-five tropical species of the subfamily are examined in detail and classified according to 1996 IUCN Red List categories. Thirty-seven species (43.5%) are considered Threatened, of which two (Cromileptes altivelis and Epinephelus akaara) are Endangered, and the remaining 35 are Vulnerable. Thirty-four species (40%) are listed as Lower Risk and do not appear to be under immediate threat. Fourteen species (16.5%) are Data Deficient. Most of the threatened species are wide ranging. Large range size and the production of abundant, dispersive offspring are characteristics of groupers that have previously been considered to make them unlikely candidates for extinction. However, rapidly intensifying fisheries employing habitat-destructive gears now encompass vast areas of the tropics, putting many species at risk. Members of the genera Epinephelus and Mycteroperca were found to he particularly at risk, probably due to their large body sizes, long life-span and late reproduction.
Abstract.
Hawkins JP, Roberts CM, Clark V (2000). The threatened status of restricted-range coral reef fish species.
ANIMAL CONSERVATION,
3, 81-88.
Author URL.
Hawkins JP, Roberts CM, Clark V (2000). The threatened status of restricted-range coral reef fish species.
Animal Conservation,
3(1), 81-88.
Abstract:
The threatened status of restricted-range coral reef fish species
Coral reefs are the most diverse ecosystem in the sea. Throughout the world they are being over-fished, polluted and destroyed, placing biodiversity at risk. To date, much of the concern over biodiversity loss has centred on local losses and the possibility of global extinction has largely been discounted. However, recent research has shown that 24% of reef fish species have restricted ranges (< 800 000 km2), with 9% highly restricted (< 50 000 km2). Restricted-range species are thought to face a greater risk of extinction than more widespread species since local impacts could cause global loss. We searched for information on status in the wild and characteristics of 397 restricted-range reef fish species. Fish body size, habitat requirements and usefulness to people were compared with those of a taxonomically-matched sample of more widespread species. We found that on average species with restricted ranges were significantly smaller (mean total length 19.1 cm versus 24.4 cm), tended to have narrower habitat requirements and were less used by people. Greater habitat specificity will tend to increase extinction risk while, if real, more limited usefulness (equivalent to exploitation) may reduce risk. Fifty-eight percent of restricted-range species were considered common/abundant in the wild and 42% uncommon/rare. Population status and threats to 319 species for which data were available were assessed according to the categories and criteria of the IUCN red list of threatened animals. A number of species were found to be rare, were exploited and had highly restricted ranges overlapping areas where reef degradation is particularly severe, placing them at a high risk of extinction. Five species were listed as Critically Endangered, two of them possibly already extinct in the wild, one as Endangered and 172 as Vulnerable. A further 126 species fell into Lower Risk categories and 11 were considered Data Deficient. Given the intensity of impacts to reefs, the broad geographical areas affected and the large numbers of restricted-range species, global extinctions seem likely. Urgent management action is now crucial for the survival of several species of reef fishes.
Abstract.
1999
Hawkins JP, Roberts CM, Van't Hof T, De Meyer K, Tratalos J, Aldam C (1999). Effects of recreational scuba diving on Caribbean coral and fish communities.
Conservation Biology,
13(4), 888-897.
Abstract:
Effects of recreational scuba diving on Caribbean coral and fish communities
Scuba diving on coral reefs is an increasingly lucrative element of tourism in the tropics, but divers can damage the reefs on which tourism depends. By studying the effects of diving we can determine what level of use is justifiable in balancing objectives of economic gain and conservation. Off the Caribbean island of Bonaire we compared coral and fish communities between undived reserves and environmentally similar dive sites where maximum use reached 6000 dives per site per year. At these levels of diving, direct physical damage to reefs was relatively minor. There were more loose fragments of living coral in dive sites than reserves and more abraded coral in high- than low-use areas. Diving had no significant effect on reef fish communities. Between 1991 and 1994, diving intensity increased 70% and coral cover declined in two of three dive sites and in all three reserves, suggesting a background stress unrelated to tourism. There was a significant decline in the proportion of old colonies of massive coral species within dive sites (19.2% loss), compared to a smaller loss in reserves (6.7%). Branching corals increased by 8.2% in dive sites, compared with 2.2% in reserves. Despite close management of reefs, diving is changing the character of Bonaire's reefs by allowing branching corals to increase at the expense of large, massive colonies. The impact of background stresses on massive corals seems to have been greater in the presence of diving. Other studies have linked disease infection to coral tissue damage, and the higher rates of abrasion we recorded in dived sites could have rendered corals there more susceptible to disease, thus mediating the decline of massive corals. Our study shows that even relatively low levels of diving can have pronounced effects manifested in shifts in dominance patterns rather than loss of overall coral cover. Bonaire's reefs have among the highest coral cover and greatest representation of ancient coral colonies of reefs anywhere in the Caribbean. Conserving the character of these reefs may require tighter controls on diving intensity.
Abstract.
Roberts CM, Hawkins JP (1999). Extinction risk in the sea.
Trends in Ecology and Evolution,
14(6), 241-246.
Abstract:
Extinction risk in the sea
Jean Baptiste de Lamarck and Thomas Huxley, two of the foremost thinkers of the 18th and 19th centuries, believed that humanity could not cause the extinction of marine species. Their opinions reflected a widespread belief that the seas were an inexhaustible source of food and wealth of which people could barely use a fraction. Such views were given weight by the abundant fisheries of the time. Additionally, the incredible fecundity and wide distributions of marine fishes, combined with limited exploitation, provided ample justification for optimism. The ideas of Huxley and Lamarck persist to this day, despite a sea change in the scale and depth of our influence on the oceans. Marine species could be at a far greater risk of extinction than we have assumed.
Abstract.
Sladek Nowlis J, Roberts CM (1999). Fisheries benefits and optimal design of marine reserves.
Fishery Bulletin,
97(3), 604-616.
Abstract:
Fisheries benefits and optimal design of marine reserves
We used fishery population models to assess the potential for marine fishery reserves, areas permanently closed to fishing, to enhance long-term fishery yields. Our models included detailed life history data. They also included the key assumptions that adults did not cross reserve boundaries and that larvae mixed thoroughly across the boundary but were retained sufficiently to produce a stock-recruitment relationship for the management area. We analyzed the results of these models to determine how reserve size, fishing mortality, and life history traits, particularly population growth potential, affected the fisheries benefits from reserves. We predict that reserves will enhance catches from any overfished population that meets our assumptions, particularly heavily overfished populations with low population growth potential. We further predict that reserves can enhance catches when they make up 40% or more of fisheries management areas, significantly higher proportions than are typical of existing reserve systems. Finally, we predict that reserves in systems that meet our assumptions will reduce annual catch variation in surrounding fishing grounds. The fisheries benefits and optimal design of marine reserves in any situation depended on the life history of the species of interest as well as its rate of fishing mortality. However, the generality of our results across a range of species suggest that marine reserves are a viable fisheries management alternative.
Abstract.
1998
Bellwood DR, Leis JM, Stobutzki IC, Sale PF, Cowen RK, Roberts CM (1998). Fishery and reef management [3] (multiple letters). Science, 279(5359), 2020-2022.
Roberts C (1998). No-take marine reserves: providing fishery and conservation benefits.
North Sea Monitor,
16(3), 4-8.
Abstract:
No-take marine reserves: providing fishery and conservation benefits
There is a growing realisation that current approaches to fishery management in Europe are failing to achieve sustainable harvests. Nor do they embrace the need for protection of marine species from the damage done to marine habitats by fishing. No-take marine reserves, areas completely closed to fishing, provide a much needed management tool capable of simultaneously delivering both fishery and conservation benefits.
Abstract.
Roberts CM (1998). Sources, sinks, and the design of marine reserve networks.
Fisheries,
23(7), 16-19.
Abstract:
Sources, sinks, and the design of marine reserve networks
Recently, enthusiasm has been growing for "source and sink" theory in understanding how dispersal influences replenishment of marine populations. Sources are areas that contribute disproportionately large quantities of recruits to future generations; sinks receive recruits but contribute little. This simple idea has been taken up by those seeking to optimize the location of no-take marine reserves. Reserves in source areas are argued to be better than those in sinks in terms of value for fisheries enhancement and conservation. However, attempting to identify sources and sinks is extremely difficult and may run contrary to management objectives by delaying reserve establishment. In any case, it is highly likely that different species have different source and sink areas and that the locations of such areas will change through time. The surest way to achieve fishery and conservation goals will be to establish dense networks of reserves that incorporate a wide variety of habitats and locations. We create source areas when we create no-take reserves.
Abstract.
1997
Roberts CM (1997). Connectivity and Management of Caribbean Coral Reefs. Science, 278(5342), 1454-1457.
Roberts CM (1997). Ecological advice for the global fisher crisis. Trends in Ecology & Evolution, 12(1), 35-38.
Roberts CM, Hawkins JP (1997). How small can a marine reserve be and still be effective?.
CORAL REEFS,
16(3), 150-150.
Author URL.
Nowlis JS, Roberts CM, Smith AH, Siirila E (1997). Human-enhanced impacts of a tropical storm on nearshore coral reefs.
Ambio,
26(8), 515-521.
Abstract:
Human-enhanced impacts of a tropical storm on nearshore coral reefs
Land development ranks among the most significant human threats to coral reefs, causing damage by promoting the erosion and transport of soil - called sediment once suspended in water. We studied the impacts of sediment on the coral communities of St. Lucia following a tropical storm. We found more sediment and coral damage on reefs closest to the mouths of large rivers. Coral mortality exceeded 50% at some sites, and the degree of coral mortality and bleaching depended on the amount of sediment at the site. Despite exemplary efforts by engineers to reduce erosion rates, we found more sediment at sites near a road under construction at the time of the storm. Collectively, our data demonstrated a major negative impact of land development on coral reefs, a problem likely to grow in scale given the growing demands for developed land and the recent frequency of large storms in the tropical Atlantic.
Abstract.
Shulman MJ, Polunin NVC, Roberts CM (1997). Reef Fisheries. Ecology, 78(7).
1996
Polunin NVC, Roberts CM, Pauly D (1996). Developments in tropical reef fisheries science and management. In (Ed) Reef Fisheries, Springer Nature, 361-377.
Readman JW, Tolosa I, Law AT, Bartocci J, Azemard S, Hamilton T, Mee LD, Wagener A, Le Tissier M, Roberts C, et al (1996). Discrete bands of petroleum hydrocarbons and molecular organic markers identified within massive coral skeletons. Marine Pollution Bulletin, 32(5), 437-443.
Roberts CM (1996). Settlement and beyond: population regulation and community structure of reef fishes. In (Ed) Reef Fisheries, Springer Nature, 85-112.
1995
ROBERTS CM (1995). Effects of Fishing on the Ecosystem Structure of Coral Reefs. Conservation Biology, 9(5), 988-995.
1994
Roberts CM (1994). 'Deconstructing' coral reefs.
Roberts CM, Polunin NVC (1994). Hol Chan: Demonstrating that marine reserves can be remarkably effective. Coral Reefs, 13(2).
McAllister DE, Schueler FW, Roberts CM, Hawkins JP (1994). Mapping and GIS analysis of the global distribution of coral reef fishes on an equal-area grid. In (Ed) Mapping the Diversity of Nature, Springer Nature, 155-175.
Roberts CM, Downing N, Price ARG (1994). Oil on troubled waters: impacts of the Gulf War on coral reefs.
Proceedings of the colloquium on global aspects of coral reefs, Miami, 1993, 132-138.
Abstract:
Oil on troubled waters: impacts of the Gulf War on coral reefs
During the 1991 Gulf War some 6-7 million barrels of oil were dumped into the Arabian Gulf. For 10 months an oily soot from blazing wells rained onto the region, obscuring the sun. Some inshore patch reefs covered by oil for several weeks suffered no more than an initial loss of mobile fauna. Offshore islands of Saudi Arabia were oiled but escaped lightly. Surveys in 1991 and 1992 suggest that these reefs remain remarkably unscathed. A survey of Kuwaiti island reefs in July 1991 also suggested an absence of subtidal effects. However, by May 1992 Kuwaiti reefs were showing signs of stress with extensive coral bleaching reported. In December 1992 they were resurveyed and data compared with surveys made before the war. Whilst there had been mortalities of Acropora and Porites at two of three islands visited, these were no greater in magnitude than kills prior to the Gulf War. Only on an inshore patch reef close to the source of the largest oil spill was a more widespread coral mortality noted. A significant decline in fish populations was also detected at Kubbar Island. Environmental stresses coupled with escalating human pressures make the long-term future for coral reefs in the Gulf very uncertain. -from Authors
Abstract.
Hawkins JP, Roberts CM (1994). The growth of coastal tourism in the Red Sea: Present and future effects on coral reefs. Ambio, 23(8), 503-508.
Hawkins JP, Roberts CM (1994). The growth of coastal tourism in the Red Sea: present and possible future effects on coral reefs.
Proceedings of the colloquium on global aspects of coral reefs, Miami, 1993, 385-391.
Abstract:
The growth of coastal tourism in the Red Sea: present and possible future effects on coral reefs
About 19% of Egypt's reefs are currently affected by tourism, but this is expected to rise to >26% by the year 2000. However, the intensity of effects on reefs is likely to increase much more during this period. Israel plans a further 50% increase in coastal tourism, Jordan 100% and Egypt a 13-fold expansion. Tourist development has already caused substantial damage to inshore reefs near Hurghada from infilling, sedimentation and over-fishing for marine curios. Elsewhere new constructions are also beginning to modify reef habitats. Until now damage to Sharm-el-Sheikh's reefs has been mainly caused by the direct effects of diving and snorkelling. Whilst current levels of recreational use appear to be sustainable, the massive expansion planned throughout the region will place the long-term future of reefs in doubt. The carrying capacity of coral reefs seems sure to be exceeded with widespread reef degradation the likely result. -from Authors
Abstract.
1993
Roberts CM (1993). Coral reefs: Health, hazards and history. Trends in Ecology & Evolution, 8(12), 425-427.
Hawkins JP, Roberts CM (1993). Effects of Recreational Scuba Diving on Coral Reefs: Trampling on Reef-Flat Communities. Journal of Applied Ecology, 30(1).
Downing N, Roberts C (1993). Has the Gulf War affected coral reefs of the northwestern Gulf?. Marine Pollution Bulletin, 27, 149-156.
Roberts CM, Polunin NVC (1993). Marine reserves: simple solutions to managing complex fisheries?.
Ambio,
22(6), 363-368.
Abstract:
Marine reserves: simple solutions to managing complex fisheries?
Fisheries on coral reefs are highly complex, can be very productive, but typically have little or no management. Use of marine reserves has been suggested as an approach. Protective management potentially has several important benefits including protection of spawning stocks; provision of recruits to replenish fishing grounds; enhancement of catches in adjacent unprotected areas through emigration; minimal requirement for information on biology of stocks; and ease of enforcement. We evaluate the evidence available to test whether reserves function as predicted on theoretical grounds. In general, field studies from widespread sites around the globe support predictions of increases in abundance and average size of fishes in protected areas. However, evidence for enhanced catches in adjacent areas is more limited. Protective management appears to hold much promise for low-cost management of reef fisheries. -from Authors
Abstract.
Price ARG, Sheppard CRC, Roberts CM (1993). The Gulf: its biological setting. Marine Pollution Bulletin, 27, 9-15.
Roberts CM (1993). Trouble ahead for coral reefs. Marine Pollution Bulletin, 26(12), 709-710.
1992
Roberts CM, Ormond RFG (1992). Butterflyfish social behaviour, with special reference to the incidence of territoriality: a review. Environmental Biology of Fishes, 34(1), 79-93.
Hawkins JP, Roberts CM (1992). Effects of recreational SCUBA diving on fore-reef slope communities of coral reefs.
Biological Conservation,
62(3), 171-178.
Abstract:
Effects of recreational SCUBA diving on fore-reef slope communities of coral reefs
This study investigated the effects of recreational SCUBA diving on the fore-reef slopes of coral reefs near Sharm-el-Sheikh, a popular resort in Egypt. Benthic communities were compared using randomly placed 1-m2 quadrats at three sites subdivided into heavily and little dived areas. There were significantly more damaged coral colonies, loose fragments of live coral, fragments of coral re-attached to the substratum, partially dead and abraded corals in areas heavily used by divers than in control areas. Damage to corals varied with growth form, branching forms being most vulnerable to breakage. Changes to communities at heavily and little dived sites were studied over 12 months using 3 × 3 m permanent quadrats. No significant increases in damage attributable to diving were detected for the three sites combined. However, when considered individually, the site which had experienced the greatest increase in diving appeared to have accumulated damage (broken coral) whereas the two others did not. For management purposes the results show that some reefs can sustain heavy levels of diving without apparent continued degradation. New dive sites can accumulate damage very rapidly. However, at the levels of diver use encountered during this study this may be more of an aesthetic than a biological problem. © 1992.
Abstract.
Roberts CM, Shepherd ARD, Ormond RFG (1992). Large-Scale Variation in Assemblage Structure of Red Sea Butterflyfishes and Angelfishes. Journal of Biogeography, 19(3).
Sheppard C, Price A, Roberts C (1992). Marine ecology of the Arabian region: patterns and processes in extreme tropical environments.
Marine ecology of the Arabian region: patterns and processes in extreme tropical environmentsAbstract:
Marine ecology of the Arabian region: patterns and processes in extreme tropical environments
The main purposes are to collate information of the region, to review marine systems and processes in the intertidal and shallow sublittoral parts of the Arabian seas, and to highlight human utilisation and environmental consequences. The first section presents the geological, geographical, climatic and oceanographic background to the area. The second section examines what is known of the region's marine communities, interpreting the relationships between the marine systems and physical conditions for: reefs and coral communities; coral reef fish assemblages; other reef components and processes; seaweeds and seasonality; seagrasses and other dynamic substrates; intertidal areas - mangal associated ecosystems, marshes, sabkha and beaches; and the pelagic system. The next section synthesizes and concludes the biogeographical material and interprets the effects of natural stress on the biota. The final section describes and discusses the human use and management of the region, including fisheries. -after Authors
Abstract.
Wrathall TJ, Roberts CM, Ormond RFG (1992). Territoriality in the butterflyfishChaetodon austriacus. Environmental Biology of Fishes, 34(3), 305-308.
1991
Roberts CM, Polunin NVC (1991). Are marine reserves effective in management of reef fisheries?. Reviews in Fish Biology and Fisheries, 1(1), 65-91.
Hawkins JP, Roberts CM, Adamson T (1991). Effects of a phosphate ship grounding on a Red Sea coral reef. Marine Pollution Bulletin, 22(11), 538-542.
Roberts CM (1991). Kingdom of the Deep Colin Willock. Boxtree, London, 1990. 191 pp. £16.95. ISBN: 1-85283-100-6. Marine Pollution Bulletin, 22(2), 97-98.
Roberts CM (1991). Larval mortality and the composition of coral reef fish communities. Trends in Ecology & Evolution, 6(3), 83-87.
Roberts CM (1991). Trophic relationships in the marine environment M. Barnes and R. N. Gibson (Eds). Aberdeen University Press, 1990. 642 pp. Price £65. ISBN: 0-08-037982-6. Marine Pollution Bulletin, 22(3).
1989
Scott P, Roberts CM (1989). Confirmation of the Specific Status of Abudefduf natalensis Hensley and Randall (Pisces: Pomacentridae). Ichthyology & Herpetology, 1989(1).
1988
Roberts C, Sheppard C (1988). Oil spill at Sharm-el-Sheikh. Marine Pollution Bulletin, 19(3), 92-93.
1987
Roberts CM (1987). Experimental analysis of resource sharing between herbivorous damselfish and blennies on the Great Barrier Reef. Journal of Experimental Marine Biology and Ecology, 111(1), 61-75.