The biodiversity of marine and coastal habitats is experiencing unprecedented change. While there are well-known drivers of these changes, such as overexploitation, climate change and pollution, there are also relatively unknown emerging issues that are poorly understood or recognized that have potentially positive or negative impacts on marine and coastal ecosystems. In this inaugural Marine and Coastal Horizon Scan, we brought together 30 scientists, policymakers and practitioners with transdisciplinary expertise in marine and coastal systems to identify new issues that are likely to have a significant impact on the functioning and conservation of marine and coastal biodiversity over the next 5-10 years. Based on a modified Delphi voting process, the final 15 issues presented were distilled from a list of 75 submitted by participants at the start of the process. These issues are grouped into three categories: ecosystem impacts, for example the impact of wildfires and the effect of poleward migration on equatorial biodiversity; resource exploitation, including an increase in the trade of fish swim bladders and increased exploitation of marine collagens; and new technologies, such as soft robotics and new biodegradable products. Our early identification of these issues and their potential impacts on marine and coastal biodiversity will support scientists, conservationists, resource managers and policymakers to address the challenges facing marine ecosystems.

Elasmobranchs (sharks, rays, and skates) are caught throughout fisheries globally, leading to over one-third of species being threatened with extinction1. Oceanic shark populations have undergone an average 71% decline over the last half century, owing to an 18-fold increase in relative fishing pressure2. Incidental capture or ‘bycatch’ is a primary driver of population declines, and poses an important challenge for species conservation3. This threat necessitates mitigation strategies that exist for sharks but are often focussed on haul-back and post-capture effects for longline fishing. We trialled a novel shark bycatch mitigation device (“SharkGuard”) in a commercial longline fishery targeting bluefin tuna (Thunnus thynnus), where bycatch consists largely of blue sharks (Prionace glauca) and pelagic stingrays (Pteroplatytrygon violacea).

Marine turtles are sensitive to harvesting because of life-cycle traits such as longevity, late maturity and natal philopatry. The take of nesting females is of conservation concern because they are key to population maintenance and has led to global efforts to protect this life stage. In the Turks and Caicos Islands (TCI; a UK Overseas Territory in the Caribbean), previous turtle fishery legislation protected nesting turtles on the beach but not in the water, where turtles over a minimum size were subject to legal take. In a 2-year study, we undertook nesting beach and in-water surveys, molecular analyses, satellite tracking and collation of fisheries landing data to investigate the populations of green
(Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles in the TCI and its turtle fishery. Adults were frequently taken in one of the region’s largest legal and artisanal turtle fisheries. We suggest that nesting populations in the TCI, which contain genetically unique
haplotypes, have diminished since the 1980s, likely as a result of the harvest of adults. Using these multiple lines of evidence, we highlight the inadequacies of the former fishery regulations and propose specific legislative amendments, which, as a result of this study, were implemented on 1 July 2014 by the TCI government. With good enforcement, these measures will protect adults breeding in the TCI and those from nesting rookeries in the region that use the waters of the TCI, improve the management of this fishery, and safeguard fisher livelihoods.

Gillnet fisheries exist throughout the oceans and have been implicated in high bycatch rates of sea turtles. In this study, we examined the effectiveness of illuminating nets with light-emitting diodes (LEDs), placed on floatlines in order to reduce sea turtle bycatch in a small-scale bottom-set gillnet fishery. In Sechura Bay, Northern Peru, 114 pairs of control and illuminated nets were deployed. The predicted mean Catch Per Unit of Effort (CPUE) of target species, standardized for environmental variables using generalized additive model analysis, was similar for both control and illuminated nets. In contrast, the predicted mean CPUE of green turtles (Chelonia mydas) was reduced by 63.9% in illuminated nets. One hundred twenty-five green turtles were caught in control nets while 62 were caught in illuminated nets. This statistically significant reduction (GAM analysis, p

Small-scale fisheries (SSFs) are crucial for global food security and cultural heritage, however, information on their spatial distribution and practices are often lacking, precluding effective management and mitigation of ecological impacts. This is acutely the case in the eastern Mediterranean basin, where, despite concerns being raised regarding the magnitude of marine turtle bycatch in SSFs over two decades ago, a poor understanding of the fishery persists. To address this knowledge gap, we characterised the SSF fleet of Northern Cyprus through a combination of onboard observations, fisher self-reporting and vessel tracking to provide the first comprehensive overview of the fishery. Northern Cyprus had a fleet size, standardised by coastline length, ranked 14th of 23 Mediterranean fleets assessed, with an estimated 49542 and 57198 fishing days in total in 2020 and 2021, respectively. Vessels operated mainly over the continental shelf (< 200 m) and were predominantly active during the night (53.2%, n = 573378 locations). Clear crepuscular peaks in vessel activity and gear deployment raise concerns over spatiotemporal overlap with vulnerable species, even within MPAs previously established to protect them. Fishers (n = 1296 fishing operations) predominantly utilised static and demersal gear types including gill nets (35.0%), trammel nets (27.3%), trammel and gill nets combined (20.3%), demersal longlines (17.0%) and handlines (0.5%). Landings composition was highly diverse with a minimum of 238 different taxa identified, including, but not limited to, 123 species of bony fish, 22 elasmobranch species, 3 marine turtle species and 12 mollusc species of which 18.6% are considered threatened either at a Mediterranean or global scale. However, over 70.0% of total landing mass was comprised of only five species including bogue (Boops boops), picarel (Spicara smaris), blotched picarel (Spicara maena), greater amberjack (Seriola dumerili) and Mediterranean parrotfish (Sparisoma cretense). As the most up to date and detailed understanding of this fishery's operating behaviours, our research compares the results obtained from onboard observer and self-reporting fisher sampling methodologies and discusses the caveats of each and identifies potential opportunities to adapt existing practices and MPAs to improve long-term sustainability of the fishery, whilst maintaining its socio-economic benefits to the local community.

AbstractGlobal catch rates of sharks and rays from artisanal fisheries are underreported, leading to a lack of data on population status. This forms a major barrier to developing effective management plans, such is the case in Central and West Africa. Over 3 years, we undertook the first systematic quantitative assessment of sharks and rays landed by an artisanal fishery in the Republic of the Congo. During 507 sampling days (mean 14 surveys per month), we recorded 73,268 individuals. These comprised 42 species, of which 81% are considered at an elevated risk of extinction. Landings were dominated by immature individuals, especially for species of conservation concern. Presence of species thought to have largely disappeared from the region such as the African wedgefish (Rhynchobatus luebberti) and smoothback angelshark (Squatina oculata) suggest Congolese waters are a potential stronghold for these species—warranting increased protection. We identified seasonality of catch within years, but not across years. Both inter‐ and intra‐annual trends varied by species, signifying annual fluctuations in catch of each species but consistent catch of all species year‐on‐year. Analysis showed increased catch between the short‐wet and the long‐wet, and the long‐dry seasons (January–February and August–September). Lowest catch was shown to occur during the short‐wet and the short‐dry seasons (October–December), which may provide an opportunity for seasonal closures or gear restrictions.

The authors regret that the printed version of the above article contained a number of errors. The correct and final version follows. The authors would like to apologise for any inconvenience caused. The edits to Fig. 4 are as follow: - the scale of the ‘Annual River Emissions’ scatter was one order of magnitude off due to scaling the scatter down to an appropriate size.- the unit of measurement of the ‘National Riverine Plastic Emissions’ is tonnes per year.

Abstract
. The Amazon River dolphin Inia geoffrensis occurs throughout the basins of the Amazon and Orinoco Rivers and is categorized as Endangered on the IUCN Red List. Using satellite tracking data from eight dolphins (one female and seven males) in the Peruvian Amazon, we demonstrate that these dolphins inhabit a variety of habitat types and have core areas and home range areas of variable magnitudes. To gain a better understanding of how threats affect these dolphins, we examined the distance of dolphin records to locations of current and potential future anthropogenic threats. On average, dolphin home ranges overlapped with fisheries by 89%. Dolphins were found at an average distance of 252 km from the nearest proposed dam and 125 km from the nearest proposed dredging site. Given that many of these threats are still in the planning stage, we advise the government to consider the negative effects these activities have already had on other riverine species before proceeding. Additionally, efforts should be made to expand river dolphin tracking programmes to span multiple seasons, to track more females at our study sites and to increase the numbers tracked overall in other areas to improve our knowledge of the species' movement patterns.

Bioko Island (Equatorial Guinea) hosts important nesting habitat for leatherback sea turtles, with the main nesting beaches found on the island's southern end. Nest monitoring and protection have been ongoing for more than two decades, although distribution and habitat range at sea remains to be determined. This study uses satellite telemetry to describe the movements of female leatherback turtles (n = 10) during and following the breeding season, tracking them to presumed offshore foraging habitats in the south Atlantic Ocean. Leatherback turtles spent 100% of their time during the breeding period within the Exclusive Economic Zone (EEZ) of Equatorial Guinea, with a core distribution focused on the south of Bioko Island extending up to 10 km from the coast. During this period, turtles spent less than 10% of time within the existing protected area. Extending the border of this area by 3 km offshore would lead to a greater than threefold increase in coverage of turtle distribution (29.8 ± 19.0% of time), while an expansion to 15 km offshore would provide spatial coverage for more than 50% of tracking time. Post-nesting movements traversed the territorial waters of Sao Tome and Principe (6.4%of tracking time), Brazil (0.85%), Ascension (1.8%), and Saint Helena (0.75%). The majority (70%) of tracking time was spent in areas beyond national jurisdiction (i.e. the High Seas). This study reveals that conservation benefits could be achieved by expanding existing protected areas stretching from the Bioko coastal zone, and suggests shared migratory routes and foraging space between the Bioko population and other leatherback turtle rookeries in this region.

. “Protect and restore ecosystems and biodiversity”
. is the second official aim of the current UN Ocean Decade (2021 to 2030) calling for the identification and protection of critical marine habitats. However, data to inform policy are often lacking altogether or confined to recent times, preventing the establishment of long-term baselines. The unique insights gained from combining bioarchaeology (palaeoproteomics, stable isotope analysis) with contemporary data (from satellite tracking) identified habitats which sea turtles have been using in the Eastern Mediterranean over five millennia. Specifically, our analysis of archaeological green turtle (
. Chelonia mydas
. ) bones revealed that they likely foraged on the same North African seagrass meadows as their modern-day counterparts. Here, millennia-long foraging habitat fidelity has been directly demonstrated, highlighting the significance (and long-term dividends) of protecting these critical coastal habitats that are especially vulnerable to global warming. We highlight the potential for historical ecology to inform policy in safeguarding critical marine habitats.
.

The biodiversity of marine and coastal habitats is experiencing unprecedented change. While there are well-known drivers of these changes, such as overexploitation, climate change and pollution, there are also relatively unknown emerging issues that are poorly understood or recognized that have potentially positive or negative impacts on marine and coastal ecosystems. In this inaugural Marine and Coastal Horizon Scan, we brought together 30 scientists, policymakers and practitioners with transdisciplinary expertise in marine and coastal systems to identify new issues that are likely to have a significant impact on the functioning and conservation of marine and coastal biodiversity over the next 5-10 years. Based on a modified Delphi voting process, the final 15 issues presented were distilled from a list of 75 submitted by participants at the start of the process. These issues are grouped into three categories: ecosystem impacts, for example the impact of wildfires and the effect of poleward migration on equatorial biodiversity; resource exploitation, including an increase in the trade of fish swim bladders and increased exploitation of marine collagens; and new technologies, such as soft robotics and new biodegradable products. Our early identification of these issues and their potential impacts on marine and coastal biodiversity will support scientists, conservationists, resource managers and policymakers to address the challenges facing marine ecosystems.

Sea turtles are considered as bio-indicators for monitoring the efficiency of restoration measures to reduce marine litter impacts on health. However, the lack of extended and standardised empirical data has prevented the accurate analysis of the factors influencing litter ingestion and the relationships with individual health. Historic data collected from 1988 and standard data collected from 2016 were harmonised to enable such analyses on necropsied loggerhead turtles (Caretta caretta) in eight Mediterranean and North-East Atlantic countries. Litter was found in 69.24 % of the 1121 individuals, mostly single-use and fishing-related plastics. Spatial location, sex and life history stage explained a minor part of litter ingestion. While no relationships with health could be detected, indicating that all individuals can be integrated as bio-indicators, the mechanistic models published in literature suggest that the high proportion of plastics in the digestive contents (38.77 % per individual) could have long-term repercussions on population dynamics.

Elasmobranchs (sharks, rays, and skates) are caught throughout fisheries globally, leading to over one-third of species being threatened with extinction1. Oceanic shark populations have undergone an average 71% decline over the last half century, owing to an 18-fold increase in relative fishing pressure2. Incidental capture or ‘bycatch’ is a primary driver of population declines, and poses an important challenge for species conservation3. This threat necessitates mitigation strategies that exist for sharks but are often focussed on haul-back and post-capture effects for longline fishing. We trialled a novel shark bycatch mitigation device (“SharkGuard”) in a commercial longline fishery targeting bluefin tuna (Thunnus thynnus), where bycatch consists largely of blue sharks (Prionace glauca) and pelagic stingrays (Pteroplatytrygon violacea).

AbstractAs part of the Post‐2020 Biodiversity Framework, nations are assessing progress over the past decade in addressing the underlying drivers that influence direct pressures on biodiversity and formulating new policies and strategies for the decade to come. For marine conservation, global marine protected area (MPA) coverage is still falling short of the 10% target set in 2010. Here we show that while this reflects a lack of progress in many low‐ and middle‐income countries, a few of these nations have met or exceeded international commitments. To provide an in‐depth explanation of how this was achieved in Gabon, we summarize the lessons learnt by our consortium of policy makers and practitioners who helped implement a comprehensive and ecologically representative network of 20 MPAs. We show the importance of creating a national framework, building long‐term stakeholder support, and focusing on research that guides implementation and policy; and outline a four‐step approach that countries and donors could use as an example to help meet international commitments. By responding to calls to share lessons learned to inform future Convention on Biological Diversity targets, we show how Gabon's experiences could inform change elsewhere.

To assign conservation status to a population, its size, trends, and distribution must be estimated. The Mediterranean green turtle population has shown signs of recovering over the past decade, likely in response to nest protection, but satellite tracking suggests adult foraging remains largely restricted to only a few key sites in the eastern Mediterranean. Previous research suggested that the majority of green turtles nesting at an important rookery in Cyprus, forage in Lake Bardawil, Egypt making an observed population increase dependent on this important site, which is under a high degree of anthropogenic maintenance. Here we provide new data that further demonstrates the importance of Lake Bardawil to green turtles that nest at other major rookeries on Cyprus, in the Karpaz Peninsula, with 74 % of satellite tracked females (n = 19) migrating to this key site. We also report on the first systematic nest counts for this area in over two decades and identify the inter-nesting habitat used by females nesting at these important beaches on the north and south coasts of the Peninsula. Comparing the oldest available 3-year nest count averages (1993–1995), with nest counts undertaken as part of this study (2017–2019), mean annual nest numbers increased from 186 to 554, an increase of 198 %. Our data confirm the continued importance of these beaches for the Mediterranean green turtle population and underscore the reliance of this endangered population on a man-made lagoon for recent increases in clutch counts at monitored beaches. The results highlight the utility of satellite telemetry to inform conservation status assessments and establishing conservation at both nesting and foraging sites across the population.

AbstractAimUnderstanding the spatial ecology of animal movements is a critical element in conserving long‐lived, highly mobile marine species. Analyzing networks developed from movements of six sea turtle species reveals marine connectivity and can help prioritize conservation efforts.LocationGlobal.MethodsWe collated telemetry data from 1235 individuals and reviewed the literature to determine our dataset's representativeness. We used the telemetry data to develop spatial networks at different scales to examine areas, connections, and their geographic arrangement. We used graph theory metrics to compare networks across regions and species and to identify the role of important areas and connections.ResultsRelevant literature and citations for data used in this study had very little overlap. Network analysis showed that sampling effort influenced network structure, and the arrangement of areas and connections for most networks was complex. However, important areas and connections identified by graph theory metrics can be different than areas of high data density. For the global network, marine regions in the Mediterranean had high closeness, while links with high betweenness among marine regions in the South Atlantic were critical for maintaining connectivity. Comparisons among species‐specific networks showed that functional connectivity was related to movement ecology, resulting in networks composed of different areas and links.Main conclusionsNetwork analysis identified the structure and functional connectivity of the sea turtles in our sample at multiple scales. These network characteristics could help guide the coordination of management strategies for wide‐ranging animals throughout their geographic extent. Most networks had complex structures that can contribute to greater robustness but may be more difficult to manage changes when compared to simpler forms. Area‐based conservation measures would benefit sea turtle populations when directed toward areas with high closeness dominating network function. Promoting seascape connectivity of links with high betweenness would decrease network vulnerability.

Due to changing environmental conditions, many species will have to migrate or occupy new suitable areas to avoid potential extinction in the current biodiversity crisis. Long-lived animals are especially vulnerable and ex-situ conservation actions can provide solutions through assisted colonisations. However, there is little empirical evidence on the process of founding new populations for such species or the feasibility of assisted colonisations as a viable conservation measure. Here, we combined genetics with reproductive data to study the rise of two wild populations of green turtles (Chelonia mydas) in the Cayman Islands as a possible outcome of a reintroduction program started 50 years ago. We show that both populations are highly related to the captive population but rapidly diverged due to genetic drift. Individuals from the reintroduced populations showed high levels of nest fidelity, within and across nesting seasons, indicating that philopatry may help reinforce the success of new populations. Additionally, we show that reintroduction from captive populations has not undermined the reproductive fitness of first generation individuals. Sea turtle reintroduction programs can, therefore, establish new populations but require scientific evaluation of costs and benefits and should be monitored over time to ensure viability in the long-term.

Plastic pollution and climate change have commonly been treated as two separate issues and sometimes are even seen as competing. Here we present an alternative view that these two issues are fundamentally linked. Primarily, we explore how plastic contributes to greenhouse gas (GHG) emissions from the beginning to the end of its life cycle. Secondly, we show that more extreme weather and floods associated with climate change, will exacerbate the spread of plastic in the natural environment. Finally, both issues occur throughout the marine environment, and we show that ecosystems and species can be particularly vulnerable to both, such as coral reefs that face disease spread through plastic pollution and climate-driven increased global bleaching events. A Web of Science search showed climate change and plastic pollution studies in the ocean are often siloed, with only 0.4% of the articles examining both stressors simultaneously. We also identified a lack of regional and industry-specific life cycle analysis data for comparisons in relative GHG contributions by materials and products. Overall, we suggest that rather than debate over the relative importance of climate change or marine plastic pollution, a more productive course would be to determine the linking factors between the two and identify solutions to combat both crises.

Globally, the number of citizen science clean-up projects, such as beach cleans, is increasing in an effort to reduce the amount of plastic pollution in the environment. Such activities offer the opportunity to gather insightful data on plastic abundance, distribution and composition. This information is key for informing effective management strategies aimed at reducing input but little work has been conducted to examine the challenges faced by existing citizen science projects, or the potential opportunities for maximising their impact. Here, we present the results of a questionnaire survey and follow-up workshop to explore the opinions of representatives from 20 organisations that deal with the issue of plastic pollution in the environment. Our results show that, of the organisations that conduct clean-up activities in the United Kingdom (UK), the majority collect data on plastic pollution to some extent. To ensure these data are scientifically meaningful and the necessary levels of public engagement are maintained, participants felt that survey protocols should be standardised across organisations and data submission should be as simple and easy as possible. The participants considered communication, inclusivity and volunteer diversity to be key for enhancing citizen engagement and improving data quality. Many organisations were unclear about how the information they hold can be most effectively used to help inform policies relating to managing plastic pollution. Moving forwards, there is a clear desire from clean-up organisations to collaborate with other sectors, such as commercial, policy, waste and recycling, education and technology stakeholders, as well as other non-governmental organisations and scientific researchers, to enhance the value and impact of citizen science in tackling the issue of plastic pollution.

Humpback whales (Megaptera novaeangliae) are a circumglobal species, and as capital breeders demonstrate migratory movements between high and low latitude waters in the northern and southern hemisphere. Arabian Sea humpback whales (ASHWs) are understood to be the only population of this species that is non-migratory residing annually in low latitude tropical waters, a characteristic that makes their spatial ecology unique. Interest in the presence of humpback whales in the Arabian Sea was stimulated in the mid-90s by revelations of illegal Soviet whaling that took place in the north Indian Ocean during the mid-1960’s. Dedicated field studies began off the coast of Oman in 2000, and during the course of these studies it was revealed that the population was small, (N= 82 individuals, CI 95% 60-111), and that it is vulnerable to threats from human activities at sea throughout its range. Defining the spatial relationship between threats and ASHW distribution has been identified as a management priority by member states of the International Whaling Commission and Convention on Migratory Species. However, much of our knowledge on the spatial ecology of ASHWs has been limited within the range of small vessel surveys and discrete localised sampling from passive acoustic monitoring units that identify the presence of whales through detection of song.

This thesis begins with a literature review of ASHW scientific literature with an emphasis on aspects relating to the spatial ecology of the population (Chapter 1). The analytical focus of the thesis presents results of satellite telemetry studies conducted on 14 ASHWs successfully instrumented with Argos enabled satellite tags between February 2014 and November 2017. Animal movement modelling and home range analysis revealed movements of 13 individuals predominantly along the continental shelf of the Arabian Sea coast of Oman, and the return migratory movement of a single female between the Gulf of Masirah (Oman) and Gulf of Mannar (southern coast of India). Dive profiles revealed by satellite tags measuring depth (n=11) demonstrated that individuals spent the majority of their time (82%) at less than 20m depth, a trait that exposes them to threats including shipping and fisheries. Evaluation of vertical and horizontal space use also revealed movements associated with localised deep diving and transiting along the continental slope off the coast of Oman (Chapter 2). The broad-scale distribution of ASHWs was modelled along the coast of Oman, eastern Iran and using satellite telemetry location data and remotely sensed environmental data within an ensemble ecological niche modelling (EENM) framework. The described distribution also supports the hypothesis for an important but yet unstudied part of the ASHW range in the north east Arabian Sea (Chapter 3). The high risk to whales from ship strike along the Arabian Sea coast of Oman is revealed through pairing of EENM mapping products with satellite based Automatic Identification System (s-AIS) ship tacking data. We demonstrate that ship strike risk reduction can be achieved through vessel re-routing measures, and that these would need to be addressed through International Maritime Organisation procedures for their implementation to become a reality (Chapter 4). The thesis concludes with an overview of how the insights gained from the presented studies has evolved our understanding of the spatial ecology of ASHWs and how the results can be applied to mitigate threats. Recent studies also document that 66% of ASHWs have had interaction with fishing gear. We consider that exposure to fishing and shipping related threats in the areas defined by this study is a concern given that potential biological removal (PBR) parameters indicate the population may only sustain a loss of one animal every two years to anthropogenic causes. As such we advocate for timely use of our findings to initially investigate and address threats to the population in the most important areas of habitat that we identify (Chapter 5).

The eastern Mediterranean is a region that has been relatively understudied with regards to anthropogenic marine litter despite potential for environmental and social costs. Here, coastal marine litter accumulation was assessed at eight beach locations along the coast of Northern Cyprus. Monthly surveys were performed between January 2017 and January 2019. All items ≥ 2.5 cm in diameter within the same 250 m2 plot were collected and processed. A total of 59,556 separate items were collected with a total mass of 697 kg. At the worst affected site (Ronnas Bay) litter accumulation averaged 1114 items and 11.9 kg per month. Plastic and polystyrene litter accounted for 82% (622.71 kg) of all litter types by mass and 96% (57,231) by frequency. Plastic bags, plastic pieces, drinks containers, caps/lids were the four most abundant forms of plastic by mass and by frequency. This suggests dumping/poor domestic waste governance as the main driver of marine litter in the region.

Given differing trajectories of sea turtle populations worldwide, there is a need to assess and report long-term population trends and determine which conservation strategies are effective. In this study, we report on sea turtle nest monitoring in the Cayman Islands over a 22-year period. We found that green (Chelonia mydas) and loggerhead (Caretta caretta) nest numbers increased significantly across the three islands since monitoring began in 1998, but that hawksbill nest numbers remained low with a maximum of 13 nests recorded in a season. Comparing the first 5 years of nest numbers to the most recent 5 years, the greatest percentage increase in green turtle nests was in Grand Cayman from 82 to 1,005 nests (1,126%), whereas the greatest percentage increase for loggerhead turtle nests was in Little Cayman from 10 to 290 nests (3,800%). A captive breeding operation contributed to the increase in the Grand Cayman green turtle population, however, loggerhead turtles were never captive-bred, and these populations began to increase after a legal traditional turtle fishery became inactive in 2008. Although both species have shown significant signs of recovery, populations remain at a fragment of their historical level and are vulnerable to threats. Illegal harvesting occurs to this day, with multiple females taken from nesting beaches each year. For nests and hatchlings, threats include artificial lighting on nesting beaches, causing hatchlings to misorient away from the sea, and inundation of nests by seawater reducing hatch success. The impacts of lighting were found to increase over the monitoring period. Spatial data on nest distribution was used to identify critical nesting habitat for green and loggerhead turtles and is used by the Cayman Islands Department of Environment to facilitate remediation of threats related to beachside development and for targeted future management efforts.

Climate change is a threat to marine turtles that is expected to affect all of their life stages. To guide future research, we conducted a review of the most recent literature on this topic, highlighting knowledge gains and research gaps since a similar previous review in 2009. Most research has been focussed on the terrestrial life history phase, where expected impacts will range from habitat loss and decreased reproductive success to feminization of populations, but changes in reproductive periodicity, shifts in latitudinal ranges, and changes in foraging success are all expected in the marine life history phase. Models have been proposed to improve estimates of primary sex ratios, while technological advances promise a better understanding of how climate can influence different life stages and habitats. We suggest a number of research priorities for an improved understanding of how climate change may impact marine turtles, including: improved estimates of primary sex ratios, assessments of the implications of female-biased sex ratios and reduced male production, assessments of the variability in upper thermal limits of clutches, models of beach sediment movement under sea level rise, and assessments of impacts on foraging grounds. Lastly, we suggest that it is not yet possible to recommend manipulating aspects of turtle nesting ecology, as the evidence base with which to understand the results of such interventions is not robust enough, but that strategies for mitigation of stressors should be helpful, providing they consider the synergistic effects of climate change and other anthropogenic-induced threats to marine turtles, and focus on increasing resilience.

Agroforest mosaics represent one of the most extensive human-impacted terrestrial systems worldwide and play an increasingly critical role in wildlife conservation. In such dynamic shared landscapes, coexistence can be compromised if people view wildlife as a source of infectious disease. A cross-disciplinary One Health knowledge base can help to identify evolving proponents and threats to sustainable coexistence and establish long-term project goals. Building on an existing knowledge base of human–wildlife interactions at Cantanhez National Park (NP), Guinea-Bissau, we developed a causal pathway Theory-of-Change approach in response to a newly identified disease threat of leprosy in the Critically Endangered western chimpanzee (Pan troglodytes verus). The goals of our project are to improve knowledge and surveillance of leprosy in humans and wildlife and increase capacity to manage human–wildlife interactions. We describe the core project activities that aim to (1) quantify space use by chimpanzees across Cantanhez NP and determine the distribution of leprosy in chimpanzees; (2) understand the health system and local perceptions of disease; and (3) identify fine-scale risk sites through participatory mapping of resources shared by humans and chimpanzees across target villages. We discuss the development of a biodiversity and health monitoring programme, an evidence-based One Health campaign, and a One Health environmental management plan that incorporates the sharing of space and resources, and the disease implications of human–non-human great ape interactions. We demonstrate the importance of multi-stakeholder engagement, and the development of strategy that fully considers interactions between people, wildlife, and the environment.

AbstractDietary studies provide key insights into threats and changes within ecosystems and subsequent impacts on focal species. Diet is particularly challenging to study within marine environments and therefore is often poorly understood. Here, we examined the diet of stranded and bycaught loggerhead (Caretta caretta) and green turtles (Chelonia mydas) in North Cyprus (35.33° N, 33.47° E) between 2011 and 2019. A total of 129 taxa were recorded in the diet of loggerhead turtles (n = 45), which were predominantly carnivorous (on average 72.1% of dietary biomass), foraging on a large variety of invertebrates, macroalgae, seagrasses and bony fish in low frequencies. Despite this opportunistic foraging strategy, one species was particularly dominant, the sponge Chondrosia reniformis (21.5%). Consumption of this sponge decreased with increasing turtle size. A greater degree of herbivory was found in green turtles (n = 40) which predominantly consumed seagrasses and macroalgae (88.8%) with a total of 101 taxa recorded. The most dominant species was a Lessepsian invasive seagrass, Halophila stipulacea (31.1%). This is the highest percentage recorded for this species in green turtle diet in the Mediterranean thus far. With increasing turtle size, the percentage of seagrass consumed increased with a concomitant decrease in macroalgae. Seagrass was consumed year-round. Omnivory occurred in all green turtle size classes but reduced in larger turtles (&gt; 75 cm CCL) suggesting a slow ontogenetic dietary shift. Macroplastic ingestion was more common in green (31.6% of individuals) than loggerhead turtles (5.7%). This study provides the most complete dietary list for marine turtles in the eastern Mediterranean.

AbstractEstimating life‐history traits and understanding their variation underpins the management of long‐lived, migratory animals, while knowledge of recovery dynamics can inform the management of conservation‐dependent species. Using a combination of nest counts and individual‐based life‐history data collected since 1993, we explore the drivers underlying contrasting population recovery rates of sympatrically nesting loggerhead (Caretta caretta) and green (Chelonia mydas) turtles in North Cyprus. We found that nest counts of loggerhead and green turtles from 28 beaches across the island increased by 46% and 162%, respectively over the past 27 years. A Bayesian state‐space model revealed that, at our individual‐based monitoring site, nesting of green turtles increased annually at four times the rate of that of loggerhead turtles. Furthermore, we found that loggerhead turtles nesting at the individual‐based monitoring site had stable reproductive parameters and average adult survival for the species and are the smallest breeding adults globally. Based on results from multiple matrix model scenarios, we propose that higher mortality rates of individuals in all age classes (likely driven by differences in life history and interaction with fisheries), rather than low reproductive output, are impeding the recovery of this species. While the increase in green turtles is encouraging, the Mediterranean population is estimated to have around 3,400 adults and is restricted to the Eastern Basin. The recovery of loggerhead turtles is likely to be compromised until mortality rates in the region are adequately quantified and mitigated. As survival of immature individuals is a powerful driver for sea turtle population numbers, additional efforts should target management at pelagic and neritic foraging areas. Understanding threats faced by immature life stages is crucial to accurately parameterise population models and to target conservation actions for long‐lived marine vertebrates.

Synthetic debris, more specifically plastic pollution, is a major concern to ocean ecosystems and wildlife globally. Five major accumulation zones (i.e. gyres) are identified to hold vast quantities of floating debris with concerns the Arctic is fast becoming a sixth. Despite growing research and political action, rates of production and emission continue to rise, with recent reports estimating around 10 million tonnes of plastic leaks into the marine environment every year (Boucher and Friot, 2017). This number forecast to increase in coming years (Geyer, Jambeck and Law, 2017).

In Chapter 1 I present comparable assessment of sea-surface debris concentrations across three ocean basins. Using a single methodology, sea-surface trawl samples (n=44) were obtained from numerous locations within Arctic (ARC), Atlantic (ATL) and Pacific (PAC) Ocean basins, reporting a 100% incidence of synthetic material. Although particles appear ubiquitous, I report great variability in composition and type with concentrations varying greatly over spatial scale. With most identified particles offering no clear origin or form, except for pellets or microbeads, it is likely a vast proportion of sea-surface debris is of secondary origin, likely to have been floating at sea for some time. To the best of our knowledge, this is the first study of its kind to successfully utilise a single methodology to analyse and compare sea-surface concentrations of floating marine debris in numerous ocean basins, providing data in support of theories that the Arctic Ocean is fast becoming the world’s sixth major gyre.

Chapter 2 sees me discuss and critically evaluate current attempts to combat the issue of marine plastic pollution. Encompassing both ‘hard’ (legally binding) and ‘soft’ (non-legally binding) policy, alongside preventative, mitigative, removal and behavioural strategies and solutions, developments, challenge and fragmented or flawed efforts are evaluated. Identifying ten focal point suggestions for the development of an effective global treaty, this Chapter sees me discuss avenues of research or policy - built on previous experience and success - necessary for the construction of a global agreement to combat marine plastic pollution.

The findings presented in this thesis contribute to the understanding of marine plastic pollution as a trans-boundary planetary threat demanding immediate global action. They. also highlight the need for collaborative action and research between global stakeholders, organisations, maritime industry and researchers stimulating coordinated attempts to mitigate its effect. Especially considering its support in theories suggesting concentrations of global plastic pollution in our oceans is increasing. Lastly it is hoped that both Chapter 1 and 2 provide useful criteria for methodologies (Chapter 1) and focal points (Chapter 2), to aid in the collection of baseline data, generate awareness and fundamentally aid in preventing vast quantities of plastic waste entering waterways across the globe.

Marine mammals can play important ecological roles in aquatic ecosystems, and their presence can be key to community structure and function. Consequently, marine mammals are often considered indicators of ecosystem health and flagship species. Yet, historical population declines caused by exploitation, and additional current threats, such as climate change, fisheries bycatch, pollution and maritime development, continue to impact many marine mammal species, and at least 25% are classified as threatened (Critically Endangered, Endangered or Vulnerable) on the IUCN Red List. Conversely, some species have experienced population increases/recoveries in recent decades, reflecting management interventions, and are heralded as conservation successes. To continue these successes and reverse the downward trajectories of at-risk species, it is necessary to evaluate the threats faced by marine mammals and the conservation mechanisms available to address them. Additionally, there is a need to identify evidence-based priorities of both research and conservation needs across a range of settings and taxa. To that effect we: (1) outline the key threats to marine mammals and their impacts, identify the associated knowledge gaps and recommend actions needed; (2) discuss the merits and downfalls of established and emerging conservation mechanisms; (3) outline the application of research and monitoring techniques; and (4) highlight particular taxa/populations that are in urgent need of focus.

The Endangered Mediterranean monk seal Monachus monachus is one of the most threatened marine mammals. Across Cyprus, suitable habitat and presence of monk seals is well documented and, recently, camera-trap surveys in Southern Cyprus found there to be pupping. We present results of the first camera-trap surveys in Northern Cyprus spanning the pupping period. Four adult/subadults and three pups were identified in three of eight caves monitored with camera traps. One site on the north-west of the island supported at least three adult/subadult seals and pupping occurred there in 3 consecutive years. The breeding and resting sites identified require urgent conservation to manage threats of disturbance, coastal development and fisheries bycatch. To determine the size of this population, a long-term survey with greater and more continuous coverage is required.

Understanding empowerment is integral to facilitating sustainable use policies and requires assessing potential drivers. However, critical applications are rare in conservation. Using the island of Príncipe (São Tomé and Príncipe) as a case study, we undertook household surveys (N = 869) to assess potential drivers of psychological empowerment towards conservation, measured as the perceived abilities of people to individually or collectively influence marine conservation outcomes, accounting for gender. Law enforcement, collective influence, freedom of choice and action, environmental condition and living in coastal community were key variables for understanding perceived personal influence. In particular, no-fishing areas and raising awareness about sustainable practices were recommended by those with higher self-perceived influence. Such information on target groups and factors to promote is essential for facilitating empowerment towards conservation and laying robust foundations for resource comanagement, especially given the role communities can play in the face of limited state capacity and enforcement.

Ecuador's Galapagos Islands and their unique biodiversity are a global conservation priority. We explored the presence, composition and environmental drivers of plastic contamination across the marine ecosystem at an island scale, investigated uptake in marine invertebrates and designed a systematic priority scoring analysis to identify the most vulnerable vertebrate species. Beach contamination varied by site (macroplastic 0–0.66 items·m−2, microplastics 0–448.8 particles·m−2 or 0–74.6 particles·kg−1), with high plastic accumulation on east-facing beaches that are influenced by the Humboldt Current. Local littering and waste management leakages accounted for just 2% of macroplastic. Microplastics (including anthropogenic cellulosics) were ubiquitous but in low concentrations in benthic sediments (6.7–86.7 particles·kg−1) and surface seawater (0.04–0.89 particles·m−3), with elevated concentrations in the harbour suggesting some local input. Microplastics were present in all seven marine invertebrate species examined, found in 52% of individuals (n = 123) confirming uptake of microplastics in the Galapagos marine food web. Priority scoring analysis combining species distribution information, IUCN Red List conservation status and literature evidence of harm from entanglement and ingestion of plastics in similar species identified 27 marine vertebrates in need of urgent, targeted monitoring and mitigation including pinnipeds, seabirds, turtles and sharks.

Microplastic is a ubiquitous environmental contaminant, but large gaps still exist in our knowledge of its distribution. We conducted a detailed assessment of the extent and variability of microplastic pollution in the Bristol Channel, UK. Sand samples were collected between the 5th and 30th August 2017, with microplastic recovered from 15 of the 16 beaches sampled along a coastal extent of ~230 km. In total, 1446 particles of suspected microplastic were extracted using a cascade of sieves and visual identification. The most common microplastics recovered were fragments (74%) and industrial plastic pellets (13%). We used Fourier-Transform Infrared (FTIR) spectroscopy to analyse 25% of recovered particles, 96.5% of which were confirmed as plastic, with polyethylene (61%) and polypropylene (26%) the most common polymers. Our analysis of local beach environments indicates microplastic burdens were higher on lower energy beaches with finer sediments, highlighting the importance of depositional environment in determining microplastic abundance.

Illegal, unregulated, and unreported (IUU) fishing poses a major threat to effective management of marine resources, affecting biodiversity and communities dependent on these coastal resources. Spatiotemporal patterns of industrial fisheries in developing countries are often poorly understood, and global efforts to describe spatial patterns of fishing vessel activity are currently based on automatic identification system (AIS) data. However, AIS is often not a legal requirement on fishing vessels, likely resulting in underestimates of the scale and distribution of legal and illegal fishing activity, which could have significant ramifications for targeted enforcement efforts and the management of fisheries resources. To help address this knowledge gap, we analyzed 3 years of vessel monitoring system (VMS) data in partnership with the national fisheries department in the Republic of the Congo to describe the behavior of national and distant-water industrial fleets operating in these waters. We found that the spatial footprint of the industrial fisheries fleet encompassed over one-quarter of the Exclusive Economic Zone. On average, 73% of fishing activity took place on the continental shelf (waters shallower than 200 m). Our findings highlight that VMS is not acting as a deterrent or being effectively used as a proactive management tool. As much as 33% (13% on average) of fishing effort occurred in prohibited areas set aside to protect biodiversity, including artisanal fisheries resources, and the distant-water fleet responsible for as much as 84% of this illegal activity. Given the growth in industrial and distant-water fleets across the region, as well as low levels of management and enforcement, these findings highlight that there is an urgent need for the global community to help strengthen regional and national capacity to analyze national scale data sets if efforts to combat IUU fishing are to be effective.

The COVID-19 pandemic has resulted in unparalleled global impacts on human mobility. In the ocean, ship-based activities are thought to have been impacted due to severe restrictions on human movements and changes in consumption. Here, we quantify and map global change in marine traffic during the first half of 2020. There were decreases in 70.2% of Exclusive Economic Zones but changes varied spatially and temporally in alignment with confinement measures. Global declines peaked in April, with a reduction in traffic occupancy of 1.4% and decreases found across 54.8% of the sampling units. Passenger vessels presented more marked and longer lasting decreases. A regional assessment in the Western Mediterranean Sea gave further insights regarding the pace of recovery and long-term changes. Our approach provides guidance for large-scale monitoring of the progress and potential effects of COVID-19 on vessel traffic that may subsequently influence the blue economy and ocean health.

Background. Plastic pollution affects all ecosystems, and detrimental effects to animals have been reported in a growing number of studies. However, there is a paucity of evidence for effects on terrestrial animals in comparison to those in the marine realm. Methods. We used the fly Drosophila melanogaster to study the effects that exposure to plastics may have on life history traits and immune response. We reared flies in four conditions: in media containing 1% virgin polyethylene, with no chemical additives; in media supplemented with 1% or 4% polyvinyl chloride, known to have a high content of added chemicals; and control flies in non-supplemented media. Plastic particle size ranged from 23–500 µm. We studied fly survival to viral infection, the length of the larval and pupal stage, sex ratios, fertility and the size of the resultant adult flies. We then performed crossings of F1 flies in non-supplemented media and looked at the life history traits of the F2. Results. Flies treated with plastics in the food media showed changes in fertility and sex ratio, but showed no differences in developmental times, adult size or the capacity to fight infections in comparison with controls. However, the offspring of treated flies reared in non-supplemented food had shorter life cycles, and those coming from both polyvinyl chloride treatments were smaller than those offspring of controls.

In many developing countries, small-scale fisheries provide employment and important food security for local populations. To support resource management, the description of the spatiotemporal extent of fisheries is necessary, but often poorly understood due to the diffuse nature of effort, operated from numerous small wooden vessels. Here, in Gabon, Central Africa, we applied Hidden Markov Models to detect fishing patterns in seven different fisheries (with different gears) from GPS data. Models were compared to information collected by on-board observers (7 trips) and, at a larger scale, to a visual interpretation method (99 trips). Models utilizing different sampling resolutions of GPS acquisition were also tested. Model prediction accuracy was high with GPS data sampling rates up to three minutes apart. The minor loss of accuracy linked to model classification is largely compensated by the savings in time required for analysis, especially in a context of nations or organizations with limited resources. This method could be applied to larger datasets at a national or international scale to identify and more adequately manage fishing effort.

State-space models are important tools for quality control of error-prone
animal movement data. The near real-time (within 24 h) capability of the Argos
satellite system aids dynamic ocean management of human activities by informing
when animals enter intensive use zones. This capability also facilitates use of
ocean observations from animal-borne sensors in operational ocean forecasting
models. Such near real-time data provision requires rapid, reliable quality
control to deal with error-prone Argos locations. We formulate a
continuous-time state-space model for the three types of Argos location data
(Least-Squares, Kalman filter, and Kalman smoother), accounting for irregular
timing of observations. Our model is deliberately simple to ensure speed and
reliability for automated, near real-time quality control of Argos data. We
validate the model by fitting to Argos data collected from 61 individuals
across 7 marine vertebrates and compare model-estimated locations to GPS
locations. Estimation accuracy varied among species with median Root Mean
Squared Errors usually < 5 km and decreased with increasing data sampling rate
and precision of Argos locations. Including a model parameter to inflate Argos
error ellipse sizes resulted in more accurate location estimates. In some
cases, the model appreciably improved the accuracy of the Argos Kalman smoother
locations, which should not be possible if the smoother uses all available
information. Our model provides quality-controlled locations from Argos
Least-Squares or Kalman filter data with slightly better accuracy than Argos
Kalman smoother data that are only available via reprocessing. Simplicity and
ease of use make the model suitable both for automated quality control of near
real-time Argos data and for manual use by researchers working with historical
Argos data.

AbstractCoastal areas provide critical nesting habitat for marine turtles. Understanding how artificial light might impact populations is key to guide management strategies. Here we assess the extent to which nesting populations of four marine turtle species—leatherback (Dermochelys coriacea), olive ridley (Lepidochelys olivacea), hawksbill (Eretmochelys imbricata) and two subpopulations of loggerhead (Caretta caretta) turtles—are exposed to light pollution across 604 km of the Brazilian coast. We used yearly night-time satellite images from two 5-year periods (1992–1996 and 2008–2012) from the US Air Force Defense Meteorological Satellite Programme (DMSP) to determine the proportion of nesting areas that are exposed to detectable levels of artificial light and identify how this has changed over time. Over the monitored time-frame, 63.7% of the nesting beaches experienced an increase in night light levels. Based on nest densities, we identified 54 reproductive hotspots: 62.9% were located in areas potentially exposed to light pollution. Light levels appeared to have a significant effect on nest densities of hawksbills and the northern loggerhead turtle stock, however high nest densities were also seen in lit areas. The status of all species/subpopulations has improved across the time period despite increased light levels. These findings suggest that (1) nest site selection is likely primarily determined by variables other than light and (2) conservation strategies in Brazil appear to have been successful in contributing to reducing impacts on nesting beaches. There is, however, the possibility that light also affects hatchlings in coastal waters, and impacts on population recruitment may take longer to fully manifest in nesting numbers. Recommendations are made to further this work to provide deeper insights into the impacts of anthropogenic light on marine turtles.

Marine plastic pollution is now considered a diverse contaminant suite, differing in product origin, polymer composition, size, morphology, colour, additives and environmental co-contaminants. The environmental hazards associated with marine plastic pollution have been widely documented, however much of the existing research has yet to document developmental abnormalities observed when biota develop in plastic contaminated systems. The effect of microplastic leachate exposure on two marine echinoderms early developmental stages were investigated. Psammechinus milaris and Paracentrotus lividus embryonic and larval cultures were exposed to leachates derived from industrial or environmental exposed plastic pellets to investigate the effect of polymer additives and environmental contaminants. Toxicity was evaluated morphologically using images of live embryos and larvae, along with immunostaining of key developmental tissue groups to determine the extent of impact on a physiological level. This body of work suggests that leachates from pellets exposed to environmental contaminates (biobead and pre-production nurdle pellets) and highly plasticised industrial pellets (polyvinyl chloride) elicit severe, consistent and treatment-specific phenotypes in P. lividus embryonic and larval developmental stages, with impacts on morphogenic processes. Key differences in larvae morphology were documented between plastic types and environmental exposure. Industrial polyvinyl chloride pellets elicited the most pronounced abnormalities from the wild type at 24 hours post-fertilisation. However, leachates from un-plasticised industrial polyethylene pellets showed little differences from the wildtype with regards to developmental timing and abnormalities. Leachates from environmental sourced pellets elicited the most severe developmental delays and abnormalities at 48 hours post-fertilisation. Preliminary chemical analysis was also performed on industrial and beached pellet leachates, to investigate compound composition and to determine possible contributors to the developmental defects. To summarise, the findings suggest industrial and environmental microplastic leachate exposure elicits morphological malformations and specific abnormalities in neural, cilia and muscle tissues groups in both embryonic and larval stages of marine larvae of P. lividus. However, more research and investigation are needed to draw conclusive data.

Plastic pollution is a known threat to a host of marine organisms across the world. Research in recent years has exposed numerous negative impacts on some of the world’s most threatened marine species, including turtles, cetaceans and pinnipeds. The impact of plastic pollution on elasmobranchs, however, has been relatively understudied. Sharks and rays are widely accepted to be two of the most threatened marine species in the oceans, most notably due to anthropogenic impacts including direct fisheries and bycatch. Their relationship with plastic pollution is only now being investigated in further detail. Previous studies have alluded to damaging effects on sharks and rays as a result of plastic pollution but have lacked in wide synthesis of existing information and empirical evidence. In this thesis, the impact of entanglement within and ingestion of plastic is highlighted for sharks and rays both globally and locally in the North-East Atlantic. Chapter one aimed to collect existing information on the occurrence and distribution of elasmobranch entanglement events, using a systematic literature review and novel data collection from social media site “Twitter”. Our results highlighted ghost fishing gear to be the most common entangling material for sharks and rays globally, consistent with previous studies on other marine species. The review also highlighted the lack of standardised reporting for elasmobranch entanglement and therefore resulted in the creation of an online entanglement report form for sharks and rays (ShaREN), allowing citizen scientists across the world to report entanglement incidents quickly and efficiently. Chapter two investigated the presence of microplastics and synthetic contaminant particles in four species of demersal shark found in the North-East Atlantic. Almost 70% of sharks analysed contained at least one contaminant particle,
2
however no significant relationship between size/weight and number of contaminants was identified, although further analysis was recommended. The study highlighted the ubiquity of synthetic fibres such as rayon and viscose, commonly found in clothing items, as contaminants in the marine environment. Chapter two presents the first empirical evidence of microplastic ingestion by UK shark species and highlights the pervasive nature of microplastic pollution off the English coast. While these two threats are unlikely to have significant population impacts on sharks and rays globally, similar to that of direct fisheries and bycatch, they are identified to be of clear animal welfare concern for these species. Entanglement within and ingestion of plastic is symptomatic of a degraded marine environment and highlights the need for policy-makers, scientists and stakeholders to work together to mitigate this issue for all marine species.

AbstractBycatch is one of the key threats to juvenile marine turtles in the Mediterranean Sea. As fishing methods are regional or habitat specific, the susceptibility of marine turtles may differ according to inter- and intra-population variations in foraging ecology. An understanding of these variations is necessary to assess bycatch susceptibility and to implement region-specific management. To determine if foraging ecology differs with region, sex, and size of juvenile loggerhead turtles (Caretta caretta), stable isotope analysis of carbon and nitrogen was performed on 171 juveniles from a range of foraging regions across the central and eastern Mediterranean Sea. Isotope ratios differed with geographical region, likely due to baseline variations in δ13C and δ15N values. The absence of sex-specific differences suggests that within an area, all comparably sized animals likely exploit similar foraging strategies, and therefore, their susceptibility to fisheries threats will likely be similar. The isotope ratios of juveniles occupying the North East Adriatic and North Levantine basin increased with size, potentially due to increased consumption of more prey items at higher trophic levels from a more neritic source. Isotope ratios of juveniles with access to both neritic and oceanic habitats did not differ with size which is consistent with them consuming prey items from both habitats interchangeably. With foraging habitats exploited differently among size classes in a population, the susceptibility to fisheries interactions will likely differ with size; therefore, region-specific management approaches will be needed.

Microplastic pollution is ubiquitous in the marine environment and is ingested by numerous marine species. Sharks are an understudied group regarding their susceptibility to microplastic ingestion. Here, we provide evidence of ingestion of microplastic and other anthropogenic fibres in four demersal sharks species found in the waters of the United Kingdom and investigate whether body burdens of contamination vary according to species, sex or size. Sharks were collected from the North-East Atlantic. Stomachs and digestive tracts of 46 sharks of 4 species were examined and 67% of samples contained at least one contaminant particle. Although we acknowledge modest sample size, estimated particle burden increased with body size but did not vary systematically with sex or species. A total of 379 particles were identified, leading to median estimates ranging from 2 to 7.5 ingested contaminants per animal for the 4 species. The majority were fibrous in nature (95%) and blue (88%) or black (9%) in colour. A subsample of contaminants (N = 62) were subject to FT-IR spectroscopy and polymers identified as: synthetic cellulose (33.3%), polypropylene (25%), polyacrylamides (10%) and polyester (8.3%). The level of risk posed to shark species by this level of contamination is unknown. Nevertheless, this study presents the first empirical evidence and an important baseline for ingestion of microplastics and other anthropogenic fibres in native UK shark species and highlights the pervasive nature of these pollutants.

Abstract
. Ecuador’s Galapagos Islands and their unique biodiversity are a global conservation priority. We investigated the presence, partitioning and environmental drivers of plastic contamination across the marine ecosystem, designing a systematic risk scoring analysis to identify the most vulnerable species. Beach contamination varied by site (macroplastic 0 - 0.66 items.m-2, large microplastics 0 - 448.8 particles.m-2, small microplastics 0 – 74.6 particles.kg-1), with high plastic accumulation on east-facing beaches indicating input from the Humboldt Current. Local littering and waste management leakages accounted for 2% of macroplastic. Microplastics (including synthetic cellulosics) were prevalent in sediments (6.7 - 86.7 particles.kg-1) and surface seawater (0.04 - 0.89 particles.m-3), with elevated concentrations in the harbour suggesting local input. Microplastics were present in all seven marine invertebrate species examined, found in 52% of individuals (n = 123). Risk scoring identified 32 species in need of urgent, targeted monitoring and mitigation including pinnipeds, seabirds, turtles, sharks and corals.

AbstractMigratory movements in response to seasonal resources often influence population structure and dynamics. Yet in mobile marine predators, population genetic consequences of such repetitious behaviour remain inaccessible without comprehensive sampling strategies. Temporal genetic sampling of seasonally recurring aggregations of planktivorous basking sharks, Cetorhinus maximus, in the Northeast Atlantic (NEA) affords an opportunity to resolve individual re-encounters at key sites with population connectivity and patterns of relatedness. Genetic tagging (19 microsatellites) revealed 18% of re-sampled individuals in the NEA demonstrated inter/multi-annual site-specific re-encounters. High genetic connectivity and migration between aggregation sites indicate the Irish Sea as an important movement corridor, with a contemporary effective population estimate (Ne) of 382 (CI = 241–830). We contrast the prevailing view of high gene flow across oceanic regions with evidence of population structure within the NEA, with early-season sharks off southwest Ireland possibly representing genetically distinct migrants. Finally, we found basking sharks surfacing together in the NEA are on average more related than expected by chance, suggesting a genetic consequence of, or a potential mechanism maintaining, site-specific re-encounters. Long-term temporal genetic monitoring is paramount in determining future viability of cosmopolitan marine species, identifying genetic units for conservation management, and for understanding aggregation structure and dynamics.

SummarySeabirds are one of the most threatened avian taxa and are hence a high conservation priority. Managing seabirds is challenging, requiring conservation actions at sea (e.g. Marine Protected Areas - MPAs) and on land (e.g. protection of breeding sites). Important Bird and Biodiversity Areas (IBAs) have been successfully used to identify sites of global importance for the conservation of bird populations, including breeding seabirds. The challenge of identifying suitable IBAs for tropical seabirds is exacerbated by high levels of dispersal, aseasonal and asynchronous breeding. The western Indian Ocean supports ~19 million breeding seabirds of 30 species, making it one of the most significant tropical seabird assemblages in the world. Within this is the British Indian Ocean Territory (BIOT), encompassing 55 islands of the Chagos Archipelago, which supports 18 species of breeding seabird and one of the world’s largest no-take MPAs. Between January and March in 1975 and 1996, eight and 45 islands respectively were surveyed for seabirds and the data used to designate 10 islands as IBAs. A further two were proposed following an expedition to 26 islands in February/March 2006. Due to the historic and restricted temporal and spatial nature of these surveys, the current IBA recommendations may not accurately represent the archipelago’s present seabird status and distribution. To update estimates of the BIOT breeding seabird assemblage and reassess the current IBA recommendations, we used seabird census data collected in every month except September from every island, gathered during 2008–2018. The maximum number of breeding seabirds for a nominal year was 281,596 pairs of 18 species, with three species making up 96%: Sooty Tern Onychoprion fuscatus - 70%, Lesser Noddy Anous tenuirostris - 18% and Red-footed Booby Sula sula - 8%. Phenology was a complex species-specific mix of synchronous and asynchronous breeding, as well as seasonal and aseasonal breeding. Nine of the 10 designated IBAs and the two proposed IBAs qualified for IBA status based on breeding seabirds. However, not every IBA qualified each year because Sooty Terns periodically abandoned breeding islands and Tropical Shearwater Puffinus bailloni breeding numbers dropped below IBA qualifying criteria in some years. Further, one survey per year does not always capture the periodic breeding of some tropical seabirds. We propose therefore, that IBAs in BIOT are better designated at the island cluster level rather than by specific island and require two surveys six months apart per year. This work highlights the merits of long-term, systematic, versus incidental surveys for breeding tropical seabirds and the subsequent associated designation of IBAs.

AbstractGlobally, marine turtles are considered threatened throughout their range, and therefore conservation practitioners are increasingly investing resources in marine protected areas to protect key life history stages and critical habitats, including foraging grounds, nesting beaches and inter-nesting areas. Empirical data on the distribution of these habitats and/or the spatial ecology and behaviour of individuals of many marine turtle populations are often lacking, undermining conservation efforts, particularly along the Atlantic coast of Africa. Here we contribute to the knowledge base in this region by describing patterns of habitat use for nine green turtles Chelonia mydas tagged with satellite platform transmitter terminals at a foraging ground in Loango Bay, Republic of the Congo, one of only a few documented mainland foraging grounds for marine turtles in Central Africa. Analyses of these data revealed that core areas of habitat use and occupancy for a wide range of size/age classes were restricted to shallow waters adjacent to Pointe Indienne in Loango Bay, with most individuals showing periods of high fidelity to this area. These data are timely given the Congolese government recently announced its intention to create a marine conservation zone to protect marine turtles in Loango Bay. Despite the small sample size of this study, these data exemplify the need for comprehensive strategies that span national jurisdictions, as we provide the first documented evidence of linkages between green turtle foraging sites in Central Africa (Loango Bay, Republic of the Congo) and Southern Africa (Mussulo Bay, Angola).

Plastic pollution is increasing rapidly throughout the world’s oceans and is considered a major threat to marine wildlife and ecosystems. Although known to cause lethal or sub-lethal effects to vulnerable marine megafauna, population-level impacts of plastic pollution have not been thoroughly investigated. Here, we compiled and evaluated information from peer-reviewed studies that reported deleterious individual-level effects of plastic pollution on air-breathing marine megafauna (i.e. seabirds, marine mammals, and sea turtles) worldwide, highlighting those that assessed potential population-level effects. Lethal and sub-lethal individual-level effects included drowning, starvation, gastrointestinal tract damage, malnutrition, physical injury, reduced mobility, and physiological stress, resulting in reduced energy acquisition and assimilation, compromised health, reproductive impairment, and mortality. We found 47 studies published between 1969 and 2020 that considered population-level effects of plastic entanglement (n = 26), ingestion (n = 19), or both (n = 2). of these, 7 inferred population-level effects (n = 6, entanglement; n = 1, ingestion), whereas 19 lacked evidence for effects (n = 12, entanglement; n = 6, ingestion; n = 1, both). However, no study in the past 50 yr reported direct evidence of population-level effects. Despite increased interest in and awareness of the presence of plastic pollution throughout the world’s oceans, the extent and magnitude of demographic impacts on marine megafauna remains largely unassessed and therefore unknown, in contrast to well-documented effects on individuals. Addressing this major assessment gap will allow researchers and managers to compare relative effects of multiple threats—including plastic pollution—on marine megafauna populations, thus providing appropriate context for strategic conservation priority-setting.

Vector navigation, i.e. maintaining a constant heading for a given amount of time, is hypothesized to provide a viable basis for the navigational feats of a number of long-distance animal migrants. Since animals following this strategy are subject to drift by wind or by ocean current, performing long migrations relying on vector navigation is particularly challenging. We tested whether vector navigation could be involved in the migrations of green turtles (Chelonia mydas) that migrate between the remote Ascension Island and Brazil. To this aim, a novel approach was followed using individual-based numerical models to simulate migratory trajectories of virtual turtles that were compared to actual routes reconstructed by satellite. Simulated postnesting migrations from Ascension revealed that weak currents enabled modeled turtles to reach the Brazilian coast, but only for a limited range of headings around due West. This conclusion was corroborated by comparing modeled trajectories with the actual routes of previously tracked turtles, with a beeline vector navigation strategy providing the best fit, although a true-navigation strategy directed to the landfall site produced similar results. Finally, we tested if a vector navigational strategy was feasible for the prebreeding migration from Brazil towards Ascension, but modeled routes mostly failed to reach the island or a larger area around it, with individuals drifting away under the influence of currents. We conclude that Ascension turtles can take advantage of vector navigation when migrating towards a wide target like the Brazilian coast, while the demanding prebreeding migration likely requires more complex navigational systems.

Anthropogenic noise is increasing throughout the world's oceans. One major contributor is industrial seismic surveys-a process typically undertaken to locate and estimate the quantity of oil and gas deposits beneath the seafloor-which, in recent years, has increased in magnitude and scope in some regions. Regulators permit this activity despite widespread uncertainties regarding the potential ecological impacts of seismic surveys and gaps in baseline information on some key species of conservation concern. Research to date suggests that impacts vary, from displacement to direct mortality, but these effects remain poorly understood for most species. Here, we summarize potential effects of seismic surveys, describe key knowledge gaps, and recommend broad-scale research priorities for 3 impacted taxonomic groups: fish, marine mammals, and sea turtles. We also suggest further technological advances, improved mitigation measures, and better policy and management structures to minimize the ecological impacts of seismic surveys in light of scientific uncertainty.

Ex situ management is an important conservation tool that allows the preservation of biological diversity outside natural habitats while supporting survival in the wild. Captive breeding followed by re-introduction is a possible approach for endangered species conservation and preservation of genetic variability. The Cayman Turtle Centre Ltd was established in 1968 to market green turtle (Chelonia mydas) meat and other products and replenish wild populations, thought to be locally extirpated, through captive breeding. We evaluated the effects of this re-introduction programmme using molecular markers (13 microsatellites, 800-bp D-loop and simple tandem repeat mitochondrial DNA sequences) from captive breeders (N = 257) and wild nesting females (N = 57) (sampling period: 2013-2015). We divided the captive breeders into three groups: founders (from the original stock), and then two subdivisions of F1 individuals corresponding to two different management strategies, cohort 1995 ("C1995") and multicohort F1 ("MCF1"). Loss of genetic variability and increased relatedness was observed in the captive stock over time. We found no significant differences in diversity among captive and wild groups, and similar or higher levels of haplotype variability when compared to other natural populations. Using parentage and sibship assignment, we determined that 90% of the wild individuals were related to the captive stock. Our results suggest a strong impact of the re-introduction programmme on the present recovery of the wild green turtle population nesting in the Cayman Islands. Moreover, genetic relatedness analyses of captive populations are necessary to improve future management actions to maintain genetic diversity in the long term and avoid inbreeding depression.

Most fish stocks are being extracted at unsustainable rates and through bycatch, many marine megavertebrate species have unfavourable conservation status. The sheer number and diversity of small-scale fishing vessels worldwide presents a challenge to monitoring and research, therefore compared to industrialised fisheries, little is known about their activities or their sustainability. This thesis addresses this information gap by examining motorised polyvalent vessels

The management of species of conservation concern requires high-quality life-history data to model and assess population stocks. This is particularly important for long-lived, migratory species with slow life-histories. In the case of sea turtles, the estimation of demographic parameters is a priority for the species globally and, in particular, in the Mediterranean Sea. In this thesis, I focus on green (Chelonia mydas) and loggerhead (Caretta caretta) turtles which nest sympatrically at Alagadi Beach, North Cyprus, where intensive monitoring and saturation tagging have been undertaken since 1993. This thesis aims to make use of this 26-year individual-based dataset both to further and to challenge current knowledge and theories surrounding life-history traits. More specifically, in Chapter 2, I review the state of knowledge of the growth strategy of adult sea turtles and life-history trade-offs. I highlight that, although studies of turtles in captivity have provided insights into changes in energy allocation at sexual maturity, there is a lack of data regarding the temporal variation in post-maturity growth rates in wild individuals. Thus, in Chapter 3, I provide evidence suggesting that, contrary to previous thinking, green and loggerhead turtles do not grow throughout their life. This clearly has implications for our understanding of ageing and longevity of the species. Additionally, in Chapter 4, I offer the first study of the effects of biologging device attachment on growth, reproduction and survival of nesting females. While the absence of an effect at this study site is promising considering how widely this technique is used in sea turtles, I stress the need for similar studies elsewhere to confirm this finding. Furthermore, I examine in Chapter 5 the importance of passive integrated transponder (PIT) tags and show that they greatly improve estimates of flipper tag loss and life-history and demographic parameters, essential for population assessments. Lastly, I use results from previous chapters in Chapter 6 to investigate the difference in recovery rates of the two species. I propose that high bycatch rates in the Mediterranean Sea are hampering the recovery of loggerhead turtles at this study site, whereas green turtles are showing signs of exponential recovery. In conclusion, this thesis emphasises the importance of long-term studies to refine life-history models and provides new and improved data for Mediterranean sea turtles, which can be used in regional and global IUCN Red List assessments.

Over the last sixty years, the development of synthetic and durable materials, namely plastic, coupled with a growing human population, has resulted in a rapid increase in the levels of anthropogenic debris in rivers, along coastlines and in the wider marine ecosystem. Currently, an estimated 4.8 to 12.7 million tons of plastic enter the oceans every year but this is expected to increase to between 9.6 and 25.4 million tons by 2025. As such, it is one of the most widely recognised pollution issues facing the planet due to its wide-ranging ecological and socio-economic implications. The main aims of this thesis were to i) examine citizen-science beach clean data to better understand the composition of anthropogenic litter deposited on British beaches by determining the most common items, materials, sources and pathways, and exploring the data for spatial patterns and temporal trends in litter density; ii) investigate an indirect pathway (trophic transfer) of microplastic (

Despite concerns regarding the environmental impacts of microplastics, knowledge of the incidence and levels of synthetic particles in large marine vertebrates is lacking. Here, we utilize an optimized enzymatic digestion methodology, previously developed for zooplankton, to explore whether synthetic particles could be isolated from marine turtle ingesta. We report the presence of synthetic particles in every turtle subjected to investigation (n = 102) which included individuals from all seven species of marine turtle, sampled from three ocean basins (Atlantic [ATL]: n = 30, four species; Mediterranean (MED): n = 56, two species; Pacific (PAC): n = 16, five species). Most particles (n = 811) were fibres (ATL: 77.1% MED: 85.3% PAC: 64.8%) with blue and black being the dominant colours. In lesser quantities were fragments (ATL: 22.9%: MED: 14.7% PAC: 20.2%) and microbeads (4.8%; PAC only; to our knowledge the first isolation of microbeads from marine megavertebrates). Fourier transform infrared spectroscopy (FT-IR) of a subsample of particles (n = 169) showed a range of synthetic materials such as elastomers (MED: 61.2%; PAC: 3.4%), thermoplastics (ATL: 36.8%: MED: 20.7% PAC: 27.7%) and synthetic regenerated cellulosic fibres (SRCF; ATL: 63.2%: MED: 5.8% PAC: 68.9%). Synthetic particles being isolated from species occupying different trophic levels suggest the possibility of multiple ingestion pathways. These include exposure from polluted seawater and sediments and/or additional trophic transfer from contaminated prey/forage items. We assess the likelihood that microplastic ingestion presents a significant conservation problem at current levels compared to other anthropogenic threats.

Plastic pollution represents a pervasive and increasing threat to marine ecosystems worldwide and there is a need to better understand the extent to which microplastics (

Adaptation to increasing temperatures may enable species to mitigate the long-term impacts of climate change. Sea turtles have temperature dependent sex determination (TSD) and variation in the thermal reaction norm, which influences offspring sex ratio, has been suggested as a potential adaptive mechanism to rising global temperatures. Here, we investigate the sex ratio of green turtle Chelonia mydas offspring from nests on beaches with notable differences in their thermal properties, to look for evidence of localised adaptation. We compared pivotal temperatures and hatch success in both the laboratory and in situ using eggs laid on two nesting beaches (dark vs. pale sand) at Ascension Island that represent the extremes of the range of incubation temperatures experienced by this population. We found no effect of beach of origin on pivotal temperatures, hatch success, or hatchling size in the laboratory or the wild. This suggests that turtles from the same rookery are not locally adapted to different thermal conditions experienced during incubation. Under predicted climate change scenarios, this will result in reduced hatch success and an increased proportion of female offspring unless temporal or spatial range shifts occur.

Incidental mortality (bycatch) in gillnet fisheries is a major threat to many cetacean populations. Acoustic alarms or pingers are a widely adopted management tool used to deter dolphins and porpoises from nets; however, their efficacy is largely species- and fishery-dependent. As such, results from experimental trials may have limited transferability to poorly studied species or fisheries. Here, we investigated the effect of pingers on the behaviour of Burmeister's porpoise Phocoena spinipinnis in the vicinity of the Peruvian small-scale driftnet fleet. Over a 4 yr period (2009-2012), 116 control (without pingers) and 94 experimental (with pingers) fishing sets were observed, and porpoise acoustic activity around nets was recorded using passive acoustic loggers (C-PODs). We modelled variation in detection rates as a function of pinger use and habitat covariates, and found that in regions of preferred habitat associated with cooler (17-18°C), shallow waters (within the 100 m isobath), the use of pingers lead to an 86% reduction in porpoise activity around nets. Our results suggest that pingers are likely to be particularly effective at deterring Burmeister's porpoises from fishing nets, and given the vast capacity of this and other fleets in the region, may substantially reduce mortality. This study also emphasizes the potential of passive acoustic monitoring to determine the effectiveness of bycatch mitigation measures, both for species for which visual observations are scarce, and also in regions where gathering statistically meaningful bycatch rates is logistically challenging.

Plastic debris is entering into the marine environment at an accelerating rate, now becoming one of the most ubiquitous and long-lasting changes in natural systems. Marine turtles are large marine vertebrates with complex life histories and highly mobile behaviour that may make them particularly vulnerable to its impacts. The main goals of this thesis were to i) evaluate the potential implications of the presence of plastic pollution in the environment to marine turtles by reviewing current literature ii) provide a global summary of the issue of entanglement in this taxon, utilising a global network of experts iii) explore the drivers of key interactions between marine turtles and plastic ingestion and develop novel additions classification methodologies to explore selective ingestion of plastics iv) develop a methodology for investigating and isolating the presence of microplastic ingestion in marine turtle gut content and v) examine plastic pollution on a key habitat for marine turtles e.g. nesting beaches. Major findings of the thesis include i) the issue of entanglement with plastic debris, the majority in ghost fishing gear, is both an under-reported and under-researched threat ii) a clear display of strong diet-related ingestion towards plastic debris that resemble natural food items, utilising a case study of green turtles in Northern Cyprus iii) a method development that allowed the identification and isolation of a suite synthetic particles in gut content residue samples, providing evidence of ingestion of synthetic debris at the microscopic size class iv) a more comprehensive viewpoint on plastic concentrations on nesting beaches, in the form of 3D sampling to investigate subsurface plastic densities, showing microplastics present down to turtle nesting depth of both loggerhead and green turtles in Northern Cyprus. In conclusion, this thesis forms the most detailed and comprehensive investigation to date on the impacts of this pollutant on the taxon of marine turtles; contributing to knowledge into macro and microplastic ingestion, entanglement and key habitats through method development and integration of marine turtle feeding ecology and developmental biology.

Background:. Telemetry and biologging systems, ‘tracking’ hereafter, have been instrumental in meeting the challenges associated with studying the ecology and behaviour of cryptic, wide-ranging marine mega-vertebrates. Over recent decades, globally, sea turtle tracking has increased exponentially, across species and life-stages, despite a paucity of studies investigating the effects of such devices on study animals. Indeed, such studies are key to informing whether data collected are unbiased and, whether derived estimates can be considered typical of the population at large.
Methods:. Here, using a 26-year individual-based monitoring dataset on sympatric green (Chelonia mydas) and loggerhead (Caretta caretta) turtles, we provide the first analysis of the effects of device attachment on reproduction, growth and survival of nesting females.
Results:. We found no significant difference in growth and reproductive correlates between tracked and non-tracked females in the years following device attachment. Similarly, when comparing pre- and post-tracking data, we found no significant difference in the reproductive correlates of tracked females for either species or significant carry-over effects of device attachment on reproductive correlates in green turtles. The latter was not investigated for loggerhead turtles due to small sample size. Finally, we found no significant effects of device attachment on return rates or survival of tracked females for either species.
Conclusion:. While there were no significant detrimental effects of device attachment on adult sea turtles in this region, our study highlights the need for other similar studies elsewhere and the value of long-term individual-based monitoring.

Sea turtles are a globally distributed migratory species that use a range of habitats during their life cycle, including both land and sea. As egg laying ectotherms they are particularly susceptible to variation in temperature, especially during clutch incubation. Climate change models predict increasing temperatures over the course of the century, along with sea level rise, and changes in weather patterns. Understanding how these factors impact the environment and such ectothermic species is key to their survival. The green sea turtle, Chelonia mydas, is one of the best studied sea turtle species, and like all seven species they are of conservation concern, thus understanding the impact of climate change on this group is of importance for their conservation. In this thesis I seek to investigate the impacts of temperature on offspring sex ratios and hatching success, two key parameters in the reproductive biology of sea turtles, using the Ascension Island rookery as model population. This will infer knowledge on adaptation and resilience to climate change.
I first carry out a literature review (Chapter 2) to evaluate the existing knowledge of current primary sex ratios, and find that despite nearly four decades of work on the topic, little progress has been made. Indeed, only four studies have been published on sex determining temperatures in laboratory conditions, and a range of varying methods have been used. I then carried out a laboratory-based study to establish the pivotal temperature, the temperature at which an equal proportion of male and females are produced, (29.3°C) for the Ascension Island green turtle rookery (Chapter 3) and carry out a translocation experiment to determine whether maternal philopatry confers any form of advantage to incubating clutches through localised adaptation (Chapter 4). Neither under laboratory conditions, nor in-situ do I find any evidence of localised thermal adaptation; hatching success drops with increasing temperatures, and clutches from different thermal backgrounds produce equivalent proportions of males and females. Finally, I use this information to evaluate island wide sex ratios and offspring output, based on different climate projection scenarios (Chapter 5). I find that the primary sex ratio will likely be extremely female biased (> 90%) by the end of the century, with hatching success starting to decrease in the most extreme scenarios, especially at the darker beaches where temperatures will exceed thresholds for successful incubation. The geographic isolation of Ascension Island means that there are limited opportunities for dispersal. A full assessment of the impacts of climate change on sea level rise, coastal erosion and changes in weather patterns may provide more information on the treats and opportunities that this population faces. In the meantime, a change in nesting seasonality or nesting distribution within the beaches of Ascension may provide critical to mitigate the impacts of increasing temperatures.

The distributions of migratory species in the ocean span local, national and international jurisdictions. Across these ecologically interconnected regions, migratory marine species interact with anthropogenic stressors throughout their lives. Migratory connectivity, the geographical linking of individuals and populations throughout their migratory cycles, influences how spatial and temporal dynamics of stressors affect migratory animals and scale up to influence population abundance, distribution and species persistence. Population declines of many migratory marine species have led to calls for connectivity knowledge, especially insights from animal tracking studies, to be more systematically and synthetically incorporated into decision-making. Inclusion of migratory connectivity in the design of conservation and management measures is critical to ensure they are appropriate for the level of risk associated with various degrees of connectivity. Three mechanisms exist to incorporate migratory connectivity into international marine policy which guides conservation implementation: site-selection criteria, network design criteria and policy recommendations. Here, we review the concept of migratory connectivity and its use in international policy, and describe the Migratory Connectivity in the Ocean system, a migratory connectivity evidence-base for the ocean. We propose that without such collaboration focused on migratory connectivity, efforts to effectively conserve these critical species across jurisdictions will have limited effect.

In the southwestern Atlantic Ocean, leatherback turtles Dermochelys coriacea are only known to regularly nest in eastern Brazil, on the coast of the state of Espírito Santo. Here, we present an analysis of the nesting ecology, population trends and conservation status of this leather - back turtle colony between 1988 and 2017. We observed an increasing, although variable, trend in the annual number of nests, with the mean increasing from 25.6 nests in the first 5 yr of the study to 89.8 in the last 5 yr. Concurrently, there was also a significant decrease in the mean curved carapace length of the population, which we hypothesize was caused by recruitment of new females to the nesting population. Throughout the study period, nests were concentrated in the southern part of the 160 km long study area. No change was observed in the annual median nesting date. Mean annual hatching success was 66.0% and no significant variation in hatching success was detected after a major spill of mining tailings into the nesting area in 2015. We postulate that local conservation actions that started in the 1980s have contributed to the gentle recovery of this population; however, given the small population size and restricted nesting geographical distribution alongside the persistence of various threats-fisheries bycatch, climate change, pollution and coastal development-this population continues to be of conservation concern.

AbstractMarine animals are increasingly instrumented with environmental sensors that provide large volumes of oceanographic data. Here, we conduct an innovative and comprehensive global analysis to determine the potential contribution of animal‐borne instruments (ABI) into ocean observing systems (OOSs) and provide a foundation to establish future integrated ocean monitoring programmes. We analyse the current gaps of the long‐term Argo observing system (&gt;1.5 million profiles) and assess its spatial overlap with the distribution of marine animals across eight major species groups (tuna and billfishes, sharks and rays, marine turtles, pinnipeds, cetaceans, sirenians, flying seabirds and penguins). We combine distribution ranges of 183 species and satellite tracking observations from &gt;3,000 animals. Our analyses identify potential areas where ABI could complement OOS. Specifically, ABI have the potential to fill gaps in marginal seas, upwelling areas, the upper 10 m of the water column, shelf regions and polewards of 60° latitude. Our approach provides the global baseline required to plan the integration of ABI into global and regional OOS while integrating conservation and ocean monitoring priorities.

Hawksbill turtles from nesting areas in the south of the Arabian/Persian Gulf have been shown to migrate to numerous individual foraging sites across the region and undertake "summer migration loops" (SMLs) to avoid the most extreme sea temperatures. We tracked hawksbills nesting in Kuwait (n = 4) that migrated to hitherto undescribed foraging sites but showed no evidence of SMLs despite experiencing water temperatures greater than 33°C. Increasing the sample size for Kuwait turtles, tracking males, and publishing results from other important hawksbill nesting areas in Saudi Arabia are recommended to get a fuller indication of potential behavioral plasticity in the region.

© 2019 Elsevier Ltd There have been efforts around the globe to track individuals of many marine species and assess their movements and distribution, with the putative goal of supporting their conservation and management. Determining whether, and how, tracking data have been successfully applied to address real-world conservation issues is, however, difficult. Here, we compile a broad range of case studies from diverse marine taxa to show how tracking data have helped inform conservation policy and management, including reductions in fisheries bycatch and vessel strikes, and the design and administration of marine protected areas and important habitats. Using these examples, we highlight pathways through which the past and future investment in collecting animal tracking data might be better used to achieve tangible conservation benefits.

Microplastics (plastic particles

To successfully integrate and engage the general public into marine conservation decisions it is important that individuals are well informed. This study surveyed two sample groups, marine environmental professionals working in the UK, n = 61, and members of the public surveyed in Truro, Cornwall, UK, n = 71. Public awareness of marine environmental threats and conservation efforts was assessed through comparison with the, assumed well informed, professional sample. Findings suggest that the public are generally well informed of threats to the marine environment, but are significantly less well informed about marine conservation and management strategies. Furthermore, despite indicating concern for the marine environment, members of the public display significantly fewer pro-environmental behaviours than marine conservation professionals. Public knowledge (and action) gaps are discussed as well as how these may be minimised, including a more interdisciplinary and active approach to science communication and public engagement.

Few studies have looked into climate change resilience of populations of wild animals. We use a model higher vertebrate, the green sea turtle, as its life history is fundamentally affected by climatic conditions, including temperature-dependent sex determination and obligate use of beaches subject to sea level rise (SLR). We use empirical data from a globally important population in West Africa to assess resistance to climate change within a quantitative framework. We project 200 years of primary sex ratios (1900-2100) and create a digital elevation model of the nesting beach to estimate impacts of projected SLR. Primary sex ratio is currently almost balanced, with 52% of hatchlings produced being female. Under IPCC models, we predict: (a) an increase in the proportion of females by 2100 to 76%-93%, but cooler temperatures, both at the end of the nesting season and in shaded areas, will guarantee male hatchling production; (b) IPCC SLR scenarios will lead to 33.4%-43.0% loss of the current nesting area; (c) climate change will contribute to population growth through population feminization, with 32%-64% more nesting females expected by 2120; (d) as incubation temperatures approach lethal levels, however, the population will cease growing and start to decline. Taken together with other factors (degree of foraging plasticity, rookery size and trajectory, and prevailing threats), this nesting population should resist climate change until 2100, and the availability of spatial and temporal microrefugia indicates potential for resilience to predicted impacts, through the evolution of nest site selection or changes in nesting phenology. This represents the most comprehensive assessment to date of climate change resilience of a marine reptile using the most up-to-date IPCC models, appraising the impacts of temperature and SLR, integrated with additional ecological and demographic parameters. We suggest this as a framework for other populations, species and taxa.

Fisheries depredation by marine mammals is an economic concern worldwide. We combined questionnaires, acoustic monitoring, and participatory experiments to investigate the occurrence of bottlenose dolphins in the fisheries of Northern Cyprus, and the extent of their conflict with set-nets, an economically important metier of Mediterranean fisheries. Dolphins were present in fishing grounds throughout the year and were detected at 28% of sets. Net damage was on average six times greater where dolphins were present, was correlated with dolphin presence, and the associated costs were considerable. An acoustic deterrent pinger was tested, but had no significant effect although more powerful pingers could have greater impact. However, our findings indicate that effective management of fish stocks is urgently required to address the overexploitation that is likely driving depredation behaviour in dolphins, that in turn leads to net damage and the associated costs to the fisheries.

Understanding the connectivity among populations is a key research priority for species of conservation concern. Genetic tools are widely used for this purpose, but the results can be limited by the resolution of the genetic markers in relation to the species and geographic scale. Here, we investigated natal philopatry in green turtles (Chelonia mydas) from four rookeries within close geographic proximity (~200 km) on the Mediterranean island of Cyprus. We genotyped hypervariable mtSTRs, a mtDNA control region sequence (CR) and 13 microsatellite loci to genetically characterise 479 green turtles using markers with different modes of inheritance. We demonstrated matrilineal stock structure for the first time among Mediterranean green turtle rookeries. This result contradicts previous regional assessments and supports a growing body of evidence that green turtles exhibit a more precise level of natal site fidelity than has commonly been recognised. The microsatellites detected weak male philopatry with significant stock structure among three of the six pairwise comparisons. The absence of Atlantic CR haplotypes and mtSTRs amongst these robust sample sizes reaffirms the reproductive isolation of Mediterranean green turtles and supports their status as a subpopulation. A power analysis effectively demonstrated that the mtDNA genetic markers previously employed to evaluate regional stock identity were confounded by an insufficient resolution considering the recent colonisation of this region. These findings improve the regional understanding of stock connectivity and illustrate the importance of using suitable genetic markers to define appropriate units for management and conservation.

Traditionally, growth can be either determinate, ceasing during the natural lifespan of individuals, or indeterminate, persisting throughout life. Although indeterminate growth is a widely accepted strategy and believed to be ubiquitous among long-lived species, it may not be as common as previously thought. Sea turtles are believed to be indeterminate growers despite the paucity of long-term studies into post-maturity growth. In this study, we provide the first temporal analysis of post-maturity growth rates in wild living sea turtles, using 26 yr of data on individual measurements of females nesting in Cyprus. We used generalised additive/linear mixed models to incorporate multiple growth measurements for each female and model post-maturity growth over time. We found post-maturity growth to persist in green Chelonia mydas and loggerhead Caretta caretta turtles, with growth decreasing for approximately 14 yr before plateauing around zero for a further decade solely in green turtles. We also found growth to be independent of size at sexual maturity in both species. Additionally, although annual growth and compound annual growth rates were higher in green turtles than in loggerhead turtles, this difference was not statistically significant. While indeterminate growth is believed to be a key life-history trait of ectothermic vertebrates, here, we provide evidence of determinate growth in green and loggerhead turtles and suggest that determinate growth is a life-history trait shared by cheloniid species. Our results highlight the need for long-term studies to refine life-history models and further our understanding of ageing and longevity of wild sea turtles for conservation and management.

There is widespread evidence that small-scale fisheries (SSF) bycatch threatens many populations of small cetaceans, yet conservation efforts are often limited by a lack of basic knowledge regarding their abundance, distribution, and habitat use. Here, we used passive acoustic monitoring from an SSF platform-of-opportunity to better characterize the distribution and habitat use of small cetaceans in northern Peru, focussing on the little-known Burmeister's porpoise Phocoena spinipinnis. From 2009 to 2012, acoustic click detectors (C-PODs) were attached to fishing nets for the duration of 116 fishing sets (30 fishing trips). Dolphins (unspecified delphinids) and porpoises were recorded around 71 and 22% of fishing sets, respectively. The probability of occurrence and buzzing behavior (a proxy for foraging), and time spent, were linked to both static and dynamic environmental variables to examine the drivers of habitat use. Dolphin activity was spread evenly throughout the fishing area and was not linked to any habitat variables. In contrast, porpoises were detected in neritic waters, and habitat models performed well, identifying preferences for shallow (< 200 m depth) and cooler (17-18°C) waters, close (< 50 km) to shore. The high bycatch rate of small cetaceans in Peruvian SSF gave us the unique opportunity to investigate the link between bycatch and cetacean activity around vessels. We found a positive relationship between the likelihood of a bycatch event and acoustic presence for both dolphins and porpoises, however as we did not know the timing of entanglement, we could not link vocalization rates to mortality events. Nonetheless, as small cetaceans (particularly dolphins) frequently encounter fishing boats, the likelihood of entanglements may be reduced through effective efforts to alert animals to the presence of the net, either acoustically (using acoustic alarms) or visually. This study demonstrates that passive acoustic monitoring from a fisheries platform can provide insights into the distribution and habitat use of small cetaceans at relatively low cost, and is likely to be suitable in regions with low monitoring effort and high fishing pressure.

Knowledge of life-history parameters of marine turtles is essential for understanding their ecology and for effective conservation. The leatherback turtle (Dermochelys coriacea) is globally classified as Vulnerable by the International Union of Conservation of Nature (IUCN), however, distinct subpopulations are recognised and require specific data for the assessment of their conservation status. The Southwest Atlantic Ocean subpopulation is known to regularly nest only in eastern Brazil, on the coast of the state of Espírito Santo. This thesis presents a collection of chapters that investigate the ecology and conservation of this taxon. Multiple technologies and methodologies are employed to ask both ecological and management questions, assessing key population parameters to inform conservation. Here I use long-term data (30 years) to investigate the nesting ecology, population trends and conservation status of leatherback turtles in Espírito Santo. I explore their nesting environment and provide baseline data which will guide further research and management strategies under future scenarios of climate change. I investigate the marine habitat use through stable isotope approaches and satellite telemetry to infer spatial ecology, setting out the conservation situation and perspectives of this important population. Finally, I assess the potential impacts of artificial light on wildlife, using marine turtles in Brazil as a case study. The leatherback turtle rookery in Espírito Santo shows signs of population recovery, however, the existence of various threats means this population remains subject of conservation concern.

Bycatch in net fisheries is recognized as a major source of mortality for many marine species, including seabirds. Few mitigation solutions, however, have been identified. We assessed the effectiveness of illuminating fishing nets with green light emitting diodes (LEDs) to reduce the incidental capture of seabirds. Experiments were conducted in the demersal, set gillnet fishery of Constante, Peru and compared 114 pairs of control and illuminated nets. We observed captures of a total of 45 guanay cormorants (Phalacrocorax bougainvillii), with 39 caught in control nets and six caught in illuminated nets. Seabird bycatch in terms of catch-per-unit-effort was significantly (p < 0.05) higher in control nets than in illuminated nets, representing an 85.1% decline in the cormorant bycatch rate. This study, showing that net illumination reduces seabird bycatch and previous studies showing reductions in sea turtle bycatch without reducing target catch, indicates that net illumination can be an effective multi-taxa bycatch mitigation technique. This finding has broad implications for bycatch mitigation in net fisheries given LED technology’s relatively low cost, the global ubiquity of net fisheries and the current paucity of bycatch mitigation solutions.

Although sea turtles have received substantial focus worldwide, research on the immature life stages is still relatively limited. The latter is of particular importance, given that a large proportion of sea turtle populations comprises immature individuals. We set out to identify knowledge gaps and identify the main barriers hindering research in this field. We analyzed the perceptions of sea turtle experts through an online survey which gathered their opinions on the current state of affairs on immature sea turtle research, including species and regions in need of further study, priority research questions, and barriers that have interfered with the advancement of research. Our gap analysis indicates that studies on immature leatherback Dermochelys coriacea and hawksbill Eretmochelys imbricata turtles are lacking, as are studies on all species based in the Indian, South Pacific, and South Atlantic Oceans. Experts also perceived that studies in population ecology, namely on survivorship and demography, and habitat use/behavior, are needed to advance the state of knowledge on immature sea turtles. Our survey findings indicate the need for more interdisciplinary research, collaborative efforts (e.g. data-sharing, joint field activities), and improved communication among researchers, funding bodies, stakeholders, and decision-makers.

Microplastics are highly bioavailable to marine organisms, either through direct ingestion, or indirectly by trophic transfer from contaminated prey. The latter has been observed for low-trophic level organisms in laboratory conditions, yet empirical evidence in high trophic-level taxa is lacking. In natura studies face difficulties when dealing with contamination and differentiating between directly and indirectly ingested microplastics. The ethical constraints of subjecting large organisms, such as marine mammals, to laboratory investigations hinder the resolution of these limitations. Here, these issues were resolved by analysing sub-samples of scat from captive grey seals (Halichoerus grypus) and whole digestive tracts of the wild-caught Atlantic mackerel (Scomber scombrus) they are fed upon. An enzymatic digestion protocol was employed to remove excess organic material and facilitate visual detection of synthetic particles without damaging them. Polymer type was confirmed using Fourier-Transform Infrared (FTIR) spectroscopy. Extensive contamination control measures were implemented throughout. Approximately half of scat subsamples (48%; n = 15) and a third of fish (32%; n = 10) contained 1-4 microplastics. Particles were mainly black, clear, red and blue in colour. Mean lengths were 1.5 mm and 2 mm in scats and fish respectively. Ethylene propylene was the most frequently detected polymer type in both. Our findings suggest trophic transfer represents an indirect, yet potentially major, pathway of microplastic ingestion for any species whose feeding ecology involves the consumption of whole prey, including humans. Microplastic trophic transfer in marine top predators is poorly understood; this study using captive seals found that half of the scat sub-samples and a third of the wild caught fish they were fed on contained 1-4 microplastics, indicating transfer from prey to predator.

The assessment of the composition and dynamics of endangered populations is crucial for management and conservation, and appropriate genetic markers are critical. The genetic structuring of the Mediterranean green turtle (Chelonia mydas) populations and the origin of the stranded animals found along the Israeli coast was investigated using new highly polymorphic short tandem repeat (STR) markers. The structuring of nesting populations was studied using pairwise genetic distances and a principal coordinates analysis (PCoA). The contribution of the different nesting populations to the stranded sample was assessed by using a mixed-stock analysis. A clear population genetic structure, not detected before, has been revealed. The four nesting populations are genetically well differentiated, and thus should be considered as different management units. The populations from Turkey and Israel showed higher resemblance, despite residing at opposite ends of the Mediterranean distribution. The Turkish nesting population is the main source of the stranded turtles sampled along the Israeli shore, confirming that individuals from this population migrate from north to south along the eastern shore of the Mediterranean, as previously shown by telemetry studies. The use of a highly polymorphic haplotyping method enabled the detection of a clear genetic structuring of the green turtle populations in the eastern Mediterranean Sea that was not revealed in previous studies, demonstrating the importance of marker selection in population genetics. The analysis of the genetic composition of the stranded turtles allowed us to investigate the migration patterns from nesting to foraging areas, supporting previous satellite-tracking and stable-isotope results. These results will help to delineate conservation management units for the species in the Mediterranean, and reveal connectivity among beaches and mixed aggregations.

Nest site selection is a critical behaviour, particularly in species with no parental care, as it can greatly impact offspring survival. Marine turtles depend on sandy beaches to nest, where they select from a range of microhabitats that may differently affect hatchling survival and phenotype. Here we describe the degree of nest site selection at one of the largest green turtle rookeries globally, in Guinea-Bissau, West Africa, and how this impacts offspring. In 2013 and 2014 we recorded the spatial distribution of 1559 nests, and monitored 657 females during oviposition, to assess population and individual preferences on nesting site. Overall, females tended to nest close to the vegetation, at a preferred elevation of 4.8–5.0 m, which was above the highest spring tide (4.7 m), enhancing clutch survival. Individuals displayed high repeatability in nesting microhabitat type (open sand, forest border and forest), distance along the beach, distance to the vegetation and elevation, which may result from this behaviour having a genetic basis or from fine-scale nest site philopatry. Hatchlings from cooler nests were larger, potentially dispersing faster and more able to evade predators, while smaller hatchlings, from warmer nests, retained more energetic reserves (residual yolk), which may also be advantageous for initial dispersal, particularly if food is scarce. Thus, individual preferences in nest site selection led to trade-offs in offspring phenotype, but overall, most nesting females selected sites that increased offspring survival, suggesting that nest site selection is an adaptive trait that has been under selection. As under future climate change scenarios females nesting in upper shaded areas should have higher fitness, individual consistency in nesting microhabitat provides opportunity for natural selection to occur.

The financial expense of tracking solutions often impedes effective characterisation of habitat use in threatened marine megavertebrates. Yet some of these taxa predictably aggregate at coastal breeding sites, providing conservation opportunities. Toward a low-cost solution for tracking marine megavertebrates, we trial conventional GPS data loggers against Argos satellite transmitters for assessing inter-nesting habitat use of marine turtles. Devices were attached to green (Chelonia mydas) and loggerhead (Caretta caretta) turtles nesting at a study site in Cyprus, where patrol teams were in place to retrieve GPS loggers from turtles returning to lay subsequent clutches. GPS tracking revealed loggerhead turtles to predominantly use areas outside the boundaries of an MPA proposed for the region, while both species under-used much of the MPA area. Due to high location error, Argos data were considered unsuitable for such fine-scale assessments (all location classes except Z were included in our analysis). However, Argos tracking showed half the loggerhead turtles sampled also nested outside of the patrolled study area, demonstrating connectivity with other proposed MPAs. This was not accounted for by GPS tracking, because females exhibiting this behaviour rarely returned to the study beach, precluding GPS retrieval, thus, demonstrating the power of remote data access. The low-cost GPS technology could be considered in similar cases, where recapture is likely and where funding barriers preclude the use of Argos-relay fast-acquisition GPS technology. In combining the accuracy GPS and the continuity of Argos, the latter provides the best solution in most scenarios, but at far greater cost.

Knowing the spatial scales at which effective management can be implemented is fundamental for conservation planning. This is especially important for mobile species, which can be exposed to threats across large areas, but the space use requirements of different species can vary to an extent that might render some management approaches inefficient. Here the space use patterns of seabirds were examined to provide guidance on whether conservation management approaches should be tailored for taxonomic groups with different movement characteristics. Seabird tracking data were synthesised from 5419 adult breeding individuals of 52 species in ten families that were collected in the Atlantic Ocean basin between 1998 and 2017. Two key aspects of spatial distribution were quantified, namely how far seabirds ranged from their colony, and to what extent individuals from the same colony used the same areas at sea. There was evidence for substantial differences in patterns of space-use among the ten studied seabird families, indicating that several alternative conservation management approaches are needed. Several species exhibited large foraging ranges and little aggregation at sea, indicating that area-based conservation solutions would have to be extremely large to adequately protect such species. The results highlight that short-ranging and aggregating species such as cormorants, auks, some penguins, and gulls would benefit from conservation approaches at relatively small spatial scales during their breeding season. However, improved regulation of fisheries, bycatch, pollution and other threats over large spatial scales will be needed for wide-ranging and dispersed species such as albatrosses, petrels, storm petrels and frigatebirds.

Olive ridleys (Lepidochelys olivacea) are the most numerous sea turtle species worldwide and also locally along the Pacific coast of Mexico. Published data on their distribution and nesting abundance along the coast of Nayarit and northern Jalisco, Mexico are, however, scarce. Here we describe the current extent of conservation activities and the history of efforts to protect sea turtles along this 394-km stretch of coastline. We found that 110 km (of the total of 394 km) are monitored by 18 sea turtle conservation programs, which in 2015 accounted for 43.2% of the total shoreline. Olive ridley sea turtle nesting was encountered on all monitored beaches. Our use of hatchery-protected nests as a measure of nesting levels is undoubtedly an underestimate of overall nesting in the region; however, it nevertheless provides a baseline of current nesting intensity in sites under conservation. Bahía de Banderas presented the highest nesting levels in the study area with 46.4% (3742±904; mean±SD) of the total protected nests (8073±547) while only representing 14.2% (15.4±3.8 km) of the total area monitored (109.6±4.5 km). The results provided here represent a valuable baseline upon which future research and assessments can be built when analyzing the sea turtle conservation progress in the region.

The use of satellite systems and manned aircraft surveys for remote data collection has been shown to be transformative for sea turtle conservation and research by enabling the collection of data on turtles and their habitats over larger areas than can be achieved by surveys on foot or by boat. Unmanned aerial vehicles (UAVs) or drones are increasingly being adopted to gather data, at previously unprecedented spatial and temporal resolutions in diverse geographic locations. This easily accessible, low-cost tool is improving existing research methods and enabling novel approaches in marine turtle ecology and conservation. Here we review the diverse ways in which incorporating inexpensive UAVs may reduce costs and field time while improving safety and data quality and quantity over existing methods for studies on turtle nesting, at-sea distribution and behaviour surveys, as well as expanding into new avenues such as surveillance against illegal take. Furthermore, we highlight the impact that high-quality aerial imagery captured by UAVs can have for public outreach and engagement. This technology does not come without challenges. We discuss the potential constraints of these systems within the ethical and legal frameworks which researchers must operate and the difficulties that can result with regard to storage and analysis of large amounts of imagery. We then suggest areas where technological development could further expand the utility of UAVs as data-gathering tools; for example, functioning as downloading nodes for data collected by sensors placed on turtles. Development of methods for the use of UAVs in sea turtle research will serve as case studies for use with other marine and terrestrial taxa.

We sampled 17 nesting sites for loggerhead (Caretta caretta) and green turtles (Chelonia mydas) in Cyprus. Microplastics (

Unsustainable wildlife trade affects biodiversity and the livelihoods of communities dependent upon those resources. Wildlife farming has been proposed to promote sustainable trade, but characterizing markets and understanding consumer behavior remain neglected but essential steps in the design and evaluation of such operations. We used sea turtle trade in the Cayman Islands, where turtles have been farm raised for human consumption for almost 50 years, as a case study to explore consumer preferences toward wild-sourced (illegal) and farmed (legal) products and potential conservation implications. Combining methods innovatively (including indirect questioning and choice experiments), we conducted a nationwide trade assessment through in-person interviews from September to December 2014. Households were randomly selected using disproportionate stratified sampling, and responses were weighted based on district population size. We approached 597 individuals, of which 37 (6.2%) refused to participate. Although 30% of households had consumed turtle in the previous 12 months, the purchase and consumption of wild products was rare (e.g. 64-742 resident households consumed wild turtle meat [i.e. 0.3-3.5% of households] but represented a large threat to wild turtles in the area due to their reduced populations). Differences among groups of consumers were marked, as identified through choice experiments, and price and source of product played important roles in their decisions. Despite the long-term practice of farming turtles, 13.5% of consumers showed a strong preference for wild products, which demonstrates the limitations of wildlife farming as a single tool for sustainable wildlife trade. By using a combination of indirect questioning, choice experiments, and sales data to investigate demand for wildlife products, we obtained insights about consumer behavior that can be used to develop conservation-demand-focused initiatives. Lack of data from long-term social-ecological assessments hinders the evaluation of and learning from wildlife farming. This information is key to understanding under which conditions different interventions (e.g. bans, wildlife farming, social marketing) are likely to succeed.

A key stage underpinning marine spatial planning (MSP) involves mapping the spatial distribution of ecological processes and biological features as well the social and economic interests of different user groups. One sector, merchant shipping (vessels that transport cargo or passengers), however, is often poorly represented in MSP due to a perceived lack of fine-scale spatially explicit data to support decision-making processes. Here, using the Republic of Congo as an example, we show how publicly accessible satellite-derived automatic identification system (S-AIS) data can address gaps in ocean observation data for shipping at a national scale. We also demonstrate how fine-scale (0.05 km2 resolution) spatial data layers derived from S-AIS (intensity, occupancy) can be used to generate maps of vessel pressure to provide an indication of patterns of impact on the marine environment and potential for conflict with other ocean user-groups. We reveal that passenger vessels, offshore service vessels, bulk carrier and cargo vessels and tankers account for 93.7% of all vessels and vessel traffic annually, and that these sectors operate in a combined area equivalent to 92% of Congo's exclusive economic zone—far exceeding the areas allocated for other user groups (conservation, fisheries and petrochemicals). We also show that the shallow coastal waters and habitats of the continental shelf are subject to more persistent pressure associated with shipping, and that the potential for conflict among user groups is likely to be greater with fisheries, whose zones are subject to the highest vessel pressure scores than with conservation or petrochemical sectors. Synthesis and applications. Shipping dominates ocean use, and so excluding this sector from decision-making could lead to increased conflict among user groups, poor compliance and negative environmental impacts. This study demonstrates how satellite-derived Automatic Identification System data can provide a comprehensive mechanism to fill gaps in ocean observation data and visualise patterns of vessel behaviour and potential threats to better support marine spatial planning at national scales.

Research on the values of fish populations and fisheries has primarily focused on bio-economic aspects; a more nuanced and multidimensional perspective is mostly neglected. Although a range of social aspects is increasingly being considered in fisheries research, there is still no clear understanding as to how to include these additional values within management policies nor is there a cogent appreciation of the major knowledge gaps that should be tackled by future research. This paper results from a workshop held during the 50th anniversary symposium of the Fisheries Society of the British Isles at the University of Exeter, UK, in July 2017. Here, we aim to highlight the current knowledge gaps on the values of fish populations and fisheries thus directing future research. To this end, we present eight questions that are deeply relevant to understanding the values of fish populations and fisheries. These can be applied to all habitats and fisheries, including freshwater, estuarine and marine.

Gabon hosts nesting grounds for several sea turtle species, including the world’s largest rookery for the leatherback turtle (Dermochelys coriacea), Africa’s largest rookery for the olive ridley turtle (Lepidochelys olivacea) and smaller aggregations of the hawksbill turtle (Eretmochelys imbricata) and green turtle (Chelonia mydas). To assess the level of incidental captures of turtles by the Gabonese trawl fishery, an onboard observer program was conducted in the period 2012–2013. A total of 143 turtles were captured by 15 trawlers during 271 fishing days. The olive ridley turtle was the main species captured (80% of bycaught turtles), with mostly adult-sized individuals. The remaining 20% included green turtles, hawksbill turtles, leatherback turtles and undetermined species. Bycatch per unit of effort (BPUE) of olive ridley turtles varied greatly depending on the period of the year (range of means: 0.261–2.270). Dead and comatose turtles were 6.2 and 24.6% respectively (n = 65). By applying the available fishing effort to two BPUE scenarios (excluding or considering a seasonal peak), the total annual number of captures was estimated as ranging between 1026 (CI 95% 746–1343) and 2581 (CI 95% 1641–3788) olive ridley turtles, with a mortality ranging from 63 (CI 95% 13–135) to 794 (CI 95% 415–1282) turtles per year depending on the scenario and on the fate of comatose turtles. Such a potential mortality may be reason for concern for the local breeding population of olive ridley turtles and recommendations in terms of possible conservation measures and further research are given.

Ascension Island in the South Atlantic Ocean is renowned for its globally-important nesting population of green turtles (Chelonia mydas) that has been the subject of long-term research. By comparison, very little is known about the apparently small population of hawksbill turtles (Eretmochelys imbricata) that have been recorded in its waters, thousands of kilometres from known nesting beaches. Here, we collate 10 years of in-water tagging data, opportunistic public sighting records and underwater observations to provide a baseline for future research, and present preliminary data on habitat use derived from two individuals fitted with GPS transmitters. Although public sightings were inevitably biased towards popular recreation areas, the resulting distribution suggests that hawksbill turtles occur year round in Ascension Island's waters along the entire 65 km of coastline. Hawksbills were observed feeding on benthic algae and encrusting sponges, and were frequently seen scavenging on fish discards around the Island's pier at night aided by anthropogenic lighting. Between 2003 and 2013, 35 turtles were captured, measured, tagged and then released. Curved carapace lengths ranged from 33.5 to 85 cm (mean = 48.8 cm) indicating that most (if not all) individuals encountered around Ascension are post-pelagic juveniles. Four individuals were recaptured at least once giving a mean minimum residence time of 4.2 yr (range: 2.8-7.3 yr) and a mean growth rate of 2.8 cm yr-1. Turtles fitted with Fastloc™ GPS devices remained at Ascension Island for the duration of the study (>90 days) and occupied restricted home ranges with an average area of 2.5 km2 and an average 'core use area' (50% utilization distribution) of 0.05 km2. Together, these results suggest that Ascension Island serves as a mid-Atlantic developmental habitat for benthic-feeding, juvenile hawksbill turtles on extended oceanic migrations before recruiting to their adult foraging grounds, likely to be located in Brazil or tropical West Africa.

Over 90% of those employed in commercial capture fisheries work in the small-scale fisheries (SSF) sector and an estimated 97% of small scale fishers are found in least developed countries. However, the capacity for monitoring SSF globally is low and there is a paucity of data, in particular for remote areas within developing nations. The methods presented here demonstrate a low cost participatory approach for gathering data on small-scale fisheries, in particular for those that take place across remote areas. Community-based data collectors were trained to record biological and socioeconomic data on the traditional (non-motorised) shark fishery in the Toliara region of Madagascar over a six year period (2007–2012). An estimated 20 species of shark were recorded, of which 31% (n = 3505) were Sphyrna lewini (scalloped hammerhead), a species listed by the IUCN as Endangered (IUCN, 2016). Although the number of sharks landed annually has not decreased during our survey period, there was a significant decrease in the average size of sharks caught. Despite multiple anecdotal reports of shark population declines, interviews and focus groups highlight the possibility that shark landings appear to have been maintained through changes in gear and increases in effort (eg. number of fishers, time spent fishing), which may mask a decline in shark populations. The numbers of sharks taken by the traditional fishery in our study region was estimated to be between 65,000 and 104,000 year−1, whilst estimates using national export and import of dried shark fin from Madagascar, and shark length data in this study, put total landings between 78,000 and 471,851 year−1. Reliable data on the total volume of sharks landed in Madagascar's waters is scarce, in particular from foreign industrial boats both directly targeting shark species and as bycatch in fisheries targeting other species. There is currently no legislation in place to protect sharks from overexploitation in Madagascar and an urgent need to address the lack of shark fishery management across the traditional, artisanal and industrial fisheries.

Global climate change is expected to have major impacts on biodiversity. Sea turtles have temperature-dependent sex determination, and many populations produce highly femalebiased offspring sex ratios, a skew likely to increase further with global warming. We estimated the primary sex ratio at one of the world's largest green turtle Chelonia mydas rookeries in Guinea-Bissau, West Africa, and explored its resilience to climate change. In 2013 and 2014, we deployed data loggers recording nest (n = 101) and sand (n = 30) temperatures, and identified hatchling sex by histological examination of gonads. A logistic curve was fitted to the data to allow predictions of sex ratio across habitats and through the nesting season. The population-specific pivotal temperature was 29.4°C, with both sexes produced within incubation temperatures from 27.6 to 31.4°C: the transitional range of temperatures (TRT). Primary sex ratio changed from maleto female-biased across relatively small temporal and spatial scales. Overall it was marginally female-biased, but we estimated an exceptionally high male hatchling production of 47.7% (95% CI: 36.7-58.3%) and 44.5% (95% CI: 33.8-55.4%) in 2013 and 2014, respectively. Both the temporal and spatial variation in incubation conditions and the wide range of the TRT suggest resilience and potential for adaptation to climate change if the present nesting habitat remains unchanged. These findings underline the importance of assessing site-specific parameters to understand populations' responses to climate change, particularly with regard to identifying rookeries with high male hatchling production that may be key for the future conservation of sea turtles under projected global warming scenarios.

Conservation regulations aimed at restricting resource use are commonly used to manage and protect natural resources but their implementation depends on the compliance of resource users. The design of effective regulations should be informed by an understanding of the factors that affect compliance, considering contextual socio-economic information. Changes have been implemented in the national legislation protecting marine turtles in the Cape Verde archipelago, where historical and recent records indicate heavy human predation pressure on nesting and foraging marine turtles. We present an assessment of levels of illegal harvesting and consumption of marine turtle products on two of the islands, Boa Vista and Santiago, and an analysis of their potential drivers. Key stakeholders were interviewed to investigate the perceived impact of the main interventions employed in Cape Verde to reduce illegal harvesting, trade and consumption of marine turtles. Despite an apparent decrease in harvesting and consumption, our results suggest there has been a shift from subsistence harvesting to trade in Boa Vista. The existence of laws to protect marine turtles was perceived as a deterrent to harvesting, and awareness campaigns and a lack of availability were perceived as reasons for the decrease in consumption in Boa Vista and Santiago, respectively. Aiming to inform ongoing discussions, we recommend a multi-targeted approach focusing on both suppliers and consumers to magnify conservation effectiveness. Regular impact evaluation focusing on harvest and consumption is needed to improve the design of regulations and inform policy decision making.

Madagascar is an important foraging ground for marine turtles in the Western Indian Ocean, yet the status of the country's nesting aggregations remains poorly documented. We assess the current status and trend in nesting throughout Madagascar, including data recorded by a community-based monitoring project in the Barren Isles (western Madagascar). We contextualize the findings in comparison with data from Madagascar's closest neighbouring states. Reports indicate that nesting levels have declined at many coastal sites, with no known recordings since 2000 at > 40 nesting sites. We estimate there are a minimum of 1,200 nests per year in Madagascar, with the largest recorded nesting aggregation (< 1,000 nests per year) found on islands off the west and northern coasts. The majority of nesting aggregations, including those recorded by the community-based monitoring project in the Barren Isles, are relatively small, in the order of < 50 nests per year, yet they are potentially important sources of regional genetic diversity. Nesting on many of the islands (e.g. Tromelin, Europa) around Madagascar has increased over the last 20 years, despite the fact that thousands of turtles probably originating from these sites are taken by fishers in the waters of Madagascar annually. We discuss the importance of protecting small nesting populations, and how community-based monitoring could be an important tool for conserving remote and vulnerable populations and building capacity for natural resource management.

We present the first record of the Ascension Frigatebird (Fregata aquila) for the Americas by retrieving coordinates from an individual equipped with a satellite transmitting device. As part of a wider study on the spatial and behavioral ecology of this species, we tracked a single juvenile frigatebird that entered into Brazilian waters as defined in the guidelines set forth by the Brazilian Ornithological Records Committee and the South American Checklist Committee. In total, this individual traveled ∼45,000 km over a 3.5-month period before transmissions ceased close to the exclusive economic zone of Sierra Leone. Based on the potential for this species to wander, the Ascension Frigatebird should be considered when attempting to identify any frigatebird in the Atlantic Ocean. Importantly, this record demonstrates the great potential for satellite telemetry to inform national ornithological and conservation organizations on the presence of pelagic seabirds that may otherwise be overlooked by visual surveys.

Predators exploiting tropical pelagic waters characterised by low fluctuations in seasonal temperature and salinity may require different foraging strategies than predators that can rely on persistently productive marine features. Consistent individual differences in foraging strategies have been found in temperate seabirds, but it is unclear whether such foraging special-isation would be beneficial in unpredictable tropical pelagic waters. We examined whether foraging trip characteristics of a tropical seabird were consistent between seasons and within individuals and explored whether seasonal changes could be explained by environmental variables. Ascension frigatebird Fregata aquila trips lasted up to 18 d and covered a total travel distance of up to 7047 km, but adult frigatebirds stayed within a radius of 1150 km of Ascension Island. We found that the 50% utilisation distribution of the population expanded southwestward in the cool season due to individuals performing more and longer trips in a southerly and westerly direction during the cool compared to the hot season. Individual repeatability was low (R < 0.25) for all trip characteristics, and we were unable to explain seasonal changes in time spent at sea using oceanographic or atmospheric variables. Instead, frigatebird usage per area was almost exclusively determined by distance from the colony, and although individuals spent more time in distant portions of their foraging trips, the amount of time spent per unit area decreased exponentially with increasing distance from the colony. This study indicates that, in a relatively featureless environment, high individual consistency may not be a beneficial trait for pelagic predators.

Shelf-seas are highly dynamic and oceanographically complex environments, which likely influences the spatio-temporal distributions of marine megafauna such as marine mammals. As such, understanding natural patterns in habitat use by these animals is essential when attempting to ascertain and assess the impacts of anthropogenically induced disturbances, such as those associated with marine renewable energy installations (MREIs). This study uses a five year (2009–2013) passive acoustics (C-POD) dataset to examine the use of an oceanographically dynamic marine renewable energy test site by small cetaceans, dolphins (unspecified delphinids) and harbour porpoises Phocoena phocoena, in the southern Celtic Sea. To examine how temporal patterns in habitat use across the site related to oceanographic changes occurring over broad seasonal scales as well as those driven by fine scale (bi-weekly) localised processes (that may be masked by seasonal trends), separate analyses were conducted using (1) all daily animal detection rates spanning the entire five year dataset and (2) daily animal detection rates taken only during the summer months (defined as mid-June to mid-October) of 2010 (when continuous monitoring was carried out at multiple discrete locations across the site). In both instances, generalised additive mixed effects models (GAMMs) were used to link detection rates to a suite of environmental variables representative of the oceanography of the region. We show that increased harbour porpoise detection rates in the late winter/early spring (January–March) are associated with low sea surface temperatures (SST), whilst peaks in dolphin detection rates in the summer (July–September) coincide with increased SSTs and the presence of a tidal-mixing front. Moreover, across the summer months of 2010, dolphin detection rates were found to respond to small scale changes in SST and position in the spring-neap cycle, possibly reflective of a preference for the stratified waters immediately offshore of the front. Together, these findings suggest that habitat use by small cetaceans within shelf-seas is temporally variable, species specific and likely driven by complex bottom-up processes. As such, the effective conservation management of shelf-seas requires that we understand the dynamic complexities of these systems and the species that inhabit them. In particular, we emphasise the need for a good understanding of the natural drivers of habitat use by marine megafauna before the potential impacts of anthropogenically induced disturbances, such as those associated with the construction, maintenance and operation of MREIs, can be assessed.

© 2016 the Authors. Conservation Letters published by Wiley Periodicals, Inc. Small-scale fisheries provide an essential source of food and employment for coastal communities, yet the availability of detailed information on the spatiotemporal distribution of fishing effort to support resource management at a country level is scarce. Here, using a national-scale study in the Republic of Congo, we engaged with fishers from 23 of 28 small-scale fisheries landing sites along the coast to demonstrate how combining community engagement and relatively low cost Global Positioning System (GPS) trackers can rapidly provide fine-scale information on: (1) the behavioral dynamics of the fishers and fleets that operate within this sector; and (2) the location, size and attributes of important fishing grounds upon which communities are dependent. This multidisciplinary approach should be considered within a global context where uncertainty over the behavior of marine and terrestrial resource-users can lead to management decisions that potentially compromise local livelihoods, conservation, and resource sustainability goals.

Human activities have fundamentally altered the marine environment, creating a need for effective management in one of Earth's most challenging habitats. Remote camera imagery has emerged as an essential tool for monitoring at all scales, from individuals to populations and communities up to entire marine ecosystems. Here we review the use of remote cameras to monitor the marine environment in relation to human activity, and consider emerging and potential future applications. Rapid technological advances in equipment and analytical tools influence where, why, and how remote camera imagery can be applied. We encourage the inclusion of cameras within multi-method and multi-sensor approaches to improve our understanding of ecosystems and help manage human activities and minimize impacts.

The wave energy industry is an emerging sector and a new user of maritime space that has potential to contribute significantly to the EU renewable energy goals. International and national regulatory frameworks necessitate Environmental Impact Assessments (EIA) that provide important data to inform development consent decisions. Here we have evaluated experience related to the assessment programmes at EU wave energy test centres combined with knowledge gained from EIA produced for other similar renewable energy developments. From this we have identified key receptors of concern, as well as the type and magnitude of impacts which may be expected. The key environmental receptors of concern for wave energy EIA include the physical environment (e.g. morphology, waves and current) and flora and fauna1 as represented by marine mammals, seabirds, benthos, fish and shellfish. From a review of the EIAs performed at wave energy test centres, we identified several lessons regarding the wave energy EIA process. There is clear evidence that the receptors of primary interest are dependent on factors such as the local environmental characteristics, the presence/absence of protected species and the regulatory authority under which the EIA is performed. Furthermore, it is recommended that concerns relating to cumulative impacts, from an expanding level of wave energy development taking place in a background of growing utilisation of the marine environment, which are largely unknown at this early stage of the industry may be comprehensively addressed at the national level as part of a Strategic Environmental Assessment (EIA) and/or in Maritime Spatial Planning (MSP) and that it should be regularly reassessed.

© 2014, Springer-Verlag Berlin Heidelberg.For effective management of species of conservation concern, knowledge of life history parameters is essential. Here, we present the results of one of the longest ongoing capture-mark-recapture studies of juvenile green turtles (Chelonia mydas) worldwide. From 1988 to 2013, 1,279 individual turtles were tagged in Fernando de Noronha, Brazil (3°51′S, 32°25′W). The size distribution at first capture varied between 27 and 87 cm (mean ± SD 47.9 ± 11.3 cm) curved carapace length (CCL). Median residence time was 2.4 year (with long-term residence of up to 11.2 year), with individuals exhibiting some site fidelity within the Archipelago. Turtles at this site are slow growing (mean 2.6 ± 1.6 cm year−1; range −0.9 to 7.9 cm year−1; n = 1,022), with a non-monotonic expected growth rate function and a peak in growth rates occurring at 50–60 cm CCL. At these rates, turtles in Fernando de Noronha would need to spend ca. 22 years to grow from 30 to 87 cm CCL and even longer to reach minimum adult breeding size. A Cormack–Jolly–Seber model was used to estimate the apparent survival of the residents and recapture probabilities (2001–2012). The estimated annual abundance ranged from 420 to 1,148 individuals. Confidence around abundance estimates was low, and there was no significant trend over the period, despite steep recent increases at the major source rookery. Slow growth and stable stocking numbers may be suggestive of density-dependent regulation having taken place following initial population recovery that occurred prior to the current study.

© 2016 John Wiley & Sons Ltd. Aims: Effective conservation of threatened or endangered species requires a robust understanding of their spatio-temporal distribution. Although a huge amount is known about the movements of Atlantic adult sea turtles, much less is known about juvenile turtles, and much of the life history model is therefore inferred. We set out to describe the spatio-temporal distribution of juvenile loggerheads turtles found around the Canary Islands. Location: Eastern North Atlantic Ocean. Methods: Between 1999 and 2012, we satellite-tracked 24 healthy large juvenile loggerhead turtles (mean straight carapace length = 47.4 cm, range = 34.6-54.5 cm) captured in the waters around the Canary Islands. We describe their regional distribution, identify high-use areas and create a model for habitat suitability using minimum convex polygons, density rasters and ensemble ecological niche modelling, integrated with physical and biological environmental data. Results: Turtles used a huge oceanic area (2.5 million km2) with particularly high usage around the Canary Islands, Spain, Portugal, Morocco and Western Sahara. In spring and summer, turtles generally moved further north towards the Iberian Peninsula. Ecological niche modelling identified sea surface temperature as the most important contributory variable to the habitat models. We also recorded three juvenile turtles making westward migrations away from the eastern Atlantic Ocean, presumably back towards their original natal beaches near sexual maturity. Main conclusions: the results of the present study provide insight into a significant knowledge gap on the spatio-temporal distribution of large juvenile loggerhead turtles in the eastern Atlantic Ocean. The data highlight that turtles occupy a vast open oceanic area, which hampers the ability of static conservation approaches to afford effective protection. However, ensemble ecological niche modelling highlights key suitable habitat for juvenile loggerhead turtles, which could be used in dynamic conservation protection.

Outbreaks of fibropapillomatosis (FP), a neoplastic infectious disease of marine turtles, have occurred worldwide since the 1980s. Its most likely aetiological agent is a virus, but disease expression depends on external factors, typically associated with altered environments. The scarcity of robust long-term data on disease prevalence has limited interpretations on the impacts of FP on turtle populations. Here we model the dynamics of FP at 2 green turtle foraging aggregations in Puerto Rico, through 18 yr of capture-mark-recapture data (1997-2014). We observed spatiotemporal variation in FP prevalence, potentially modulated via individual site-fidelity. FP ex pression was residency dependent, and FP-free individuals developed tumours after 1.8 ± 0.8 yr (mean ± SD) in the infected area. Recovery from the disease was likely, with complete tumour regression occurring in 2.7 ± 0.7 yr (mean ± SD). FP does not currently seem to be a major threat to marine turtle populations; however, disease prevalence is yet unknown in many areas. Systematic monitoring is highly advisable as human-induced stressors can lead to deviations in host- pathogen relationships and disease virulence. Finally, data collection should be standardized for a global assessment of FP dynamics and impacts.

As species of conservation concern, sea turtles have historically been difficult to study because of their elusive nature and extensive ranges, but improvements in telemetry have facilitated insights into life histories and behaviours which can potentially inform conservation policies. To date, there have been few assessments of the impact of satellite tracking data on species conservation, and it is difficult to clearly gauge whether the dividends justify the costs. Through an extensive review of the literature (369 papers, 1982-2014) and a questionnaire-based survey of 171 sea turtle tracking researchers, we evaluate the conservation dividends gained thus far from tracking and highlight conservation successes. We discuss who is tracking and where, where biases in effort exist, and evaluate the impact of tracking data on conservation. Conservation issues are increasingly being considered. Where research recommends policy change, the quality of advice varies and the level of uptake is still uncertain, with few clearly described examples of tracking-data actually influencing policy. The means to increase the conservation impact are discussed, including: disseminating findings more widely; communicating and collaborating with colleagues and stakeholders for more effective data sharing; community liaison, and endeavouring to close the gaps between researchers and conservation practitioners.

Seismic surveys are widely used in marine geophysical oil and gas exploration, employing airguns to produce sound-waves capable of penetrating the sea floor. In recent years, concerns have been raised over the biological impacts of this activity, particularly for marine mammals. While exploration occurs in the waters of at least fifty countries where marine turtles are present, the degree of threat posed by seismic surveys is almost entirely unknown. To investigate this issue, a mixed-methods approach involving a systematic review, policy comparison and stakeholder analysis was employed and recommendations for future research were identified. This study found that turtles have been largely neglected both in terms of research and their inclusion in mitigation policies. Few studies have investigated the potential for seismic surveys to cause behavioural changes or physical damage, indicating a crucial knowledge gap. Possible ramifications for turtles include exclusion from critical habitats, damage to hearing and entanglement in seismic survey equipment. Despite this, the policy comparison revealed that only three countries worldwide currently include turtles in their seismic mitigation guidelines and very few of the measures they specify are based on scientific evidence or proven effectiveness. Opinions obtained from stakeholder groups further highlight the urgent need for directed, in-depth empirical research to better inform and develop appropriate mitigation strategies. As seismic surveying is becoming increasingly widespread and frequent, it is important and timely that we evaluate the extent to which marine turtles, a taxon of global conservation concern, may be affected.

Aim: it is difficult to mitigate threats to marine vertebrates until their habitat use is understood. We report on a decade of satellite tracking loggerhead turtles (Caretta caretta) from an important nesting site to determine priority habitats for their protection in a region where they are known to be heavily impacted by fisheries. Location: Cyprus, Eastern Mediterranean. Method: We tracked 27 adult female loggerheads between 2001 and 2012 from North Cyprus nesting beaches. To eliminate potential biases, we included females nesting on all coasts of our study area, at different periods of the nesting season and from a range of size classes. Results: Foraging sites were distributed over the continental shelf of Cyprus, the Levant and North Africa, up to a maximum distance of 2100 km from nesting sites. Foraging sites were clustered in (1) near-shore waters of Cyprus and Syria, (2) offshore waters of Egypt and (3) offshore and near-shore regions of Libya and Tunisia. The North Cyprus and west Egypt/east Libyan coasts are important areas for loggerhead turtles during migration. Movement patterns within foraging sites strongly suggest benthic feeding in discrete areas. Early nesters visited other rookeries in Turkey, Syria and Israel where they likely laid further clutches. Tracking suggests minimum annual mortality of 11%, comparable to other fishery-impacted loggerhead populations. Main conclusions: This work further highlights the importance of neritic habitats of Libya and Tunisia as areas likely used by loggerhead turtles from many of the Mediterranean rookeries and where the threat of fisheries bycatch is high. Our tracking data also suggest that anthropogenic mortalities may have occurred in North Cyprus, Syria and Egypt; all within near-shore marine areas where small-scale fisheries operate. Protection of this species across many geopolitical units is a major challenge and documenting their distribution is an important first step.

The development of appropriate wildlife survey techniques is essential to promote effective and efficient monitoring of species of conservation concern. Here, we demonstrate the utility of two rapid-assessment, non-invasive methods to detect the presence of elusive, small, arboreal animals. We use the hazel dormouse, Muscardinus avellanarius, a rodent of conservation concern, as our focal species. Prevailing hazel dormouse survey methods are prolonged (often taking months to years to detect dormice), dependent on season and habitat, and/or have low detection rates. Alternatives would be of great use to ecologists who undertake dormouse surveys, especially those assessing the need for mitigation measures, as legally required for building development projects. Camera traps and footprint tracking are well-established tools for monitoring elusive large terrestrial mammals, but are rarely used for small species such as rodents, or in arboreal habitats. In trials of these adapted methods, hazel dormice visited bait stations and were successfully detected by both camera traps and tracking equipment at each of two woodland study sites, within days to weeks of installation. Camera trap images and footprints were of adequate quality to allow discrimination between two sympatric small mammal species (hazel dormouse and wood mouse, Apodemus sylvaticus). We discuss the relative merits of these methods with respect to research aims, funds, time available and habitat.

Marine turtles are considered keystone consumers in tropical coastal ecosystems and their decline through overexploitation has been implicated in the deterioration of reefs and seagrass pastures in the Caribbean. In the present study, we analysed stomach contents of green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) harvested in the legal turtle fishery of the Turks and Caicos Islands (Caribbean) during 2008–2010. Small juveniles to adult-sized turtles were sampled. Together with data from habitat surveys, we assessed diet composition and the taxonomic distinctness (and other species diversity measures) in the diets of these sympatric marine turtle species. The diet of green turtles (n�=�92) consisted of a total of 47 taxa: including three species of seagrass (present in 99% of individuals), 29 species of algae and eight sponge species. Hawksbill turtles (n�=�45) consumed 73 taxa and were largely spongivorous (16 species; sponges present in 100% of individuals) but also foraged on 50 species of algae (present in 73% of individuals) and three species of seagrass. Plastics were found in trace amounts in 4% of green turtle and 9% of hawksbill turtle stomach samples. We expected to find changes in diet that might reflect ontogenetic shifts from small (oceanic-pelagic) turtles to larger (coastal-benthic) turtles. Dietary composition (abundance and biomass), however, did not change significantly with turtle size, although average taxonomic distinctness was lower in larger green turtles. There was little overlap in prey between the two turtle species, suggesting niche separation. Taxonomic distinctness routines indicated that green turtles had the most selective diet, whereas hawksbill turtles were less selective than expected when compared with the relative frequency and biomass of diet items. We discuss these findings in relation to the likely important trophic roles that these sympatric turtle species play in reef and seagrass habitats.

AbstractUnderwater noise from human activities appears to be rising, with ramifications for acoustically sensitive marine organisms and the functioning of marine ecosystems. Policymakers are beginning to address the risk of ecological impact, but are constrained by a lack of data on current and historic noise levels. Here, we present the first nationally coordinated effort to quantify underwater noise levels, in support of UK policy objectives under the EU Marine Strategy Framework Directive (MSFD). Field measurements were made during 2013–2014 at twelve sites around the UK. Median noise levels ranged from 81.5–95.5 dB re 1 μPa for one-third octave bands from 63–500 Hz. Noise exposure varied considerably, with little anthropogenic influence at the Celtic Sea site, to several North Sea sites with persistent vessel noise. Comparison of acoustic metrics found that the RMS level (conventionally used to represent the mean) was highly skewed by outliers, exceeding the 97th percentile at some frequencies. We conclude that environmental indicators of anthropogenic noise should instead use percentiles, to ensure statistical robustness. Power analysis indicated that at least three decades of continuous monitoring would be required to detect trends of similar magnitude to historic rises in noise levels observed in the Northeast Pacific.

The beaches of Jaragua National Park in the Dominican Republic are the country's last known major nesting site for the leatherback marine turtle Dermochelys coriacea. This nesting aggregation is threatened by widespread illegal egg take, and clutch relocation and artificial incubation have been carried out as protection measures since 1974. We assess the efficacy of such efforts and investigate how artificial incubation may be influencing the success and sex ratios of clutches. We compare hatching success, incubation duration and embryo mortality in in-situ clutches (n = 43) with those incubated artificially at sites in the east and west of the Park (n = 35 and n = 31, respectively). Our results show that in the west, artificial incubation significantly decreases hatching success in clutches. In the east the duration of incubation is increased, which we predict would result in an increase in the number of males from these clutches. Clutch relocation is currently the only viable conservation option for clutches on eastern beaches because of illegal egg take but action is needed to ensure that the natural sex ratio is not distorted. However, on the western beaches in situ clutch incubation seems possible through beach protection. Further community engagement and enforcement are required to improve conservation measures at eastern beaches if long-term, less sustainable intervention is to be avoided.

The decline of many marine megafauna species is of global concern; but many of these species, in particular marine mammals, have been afforded international and national protection and are the focus of conservation programmes. The existing national and international legislation are reviewed through which marine megavertebrates are afforded protection in Malagasy waters. The decline and protection of marine megafauna has followed a familiar pattern in Madagascar, with two main exceptions: marine turtles and elasmobranchs remain heavily exploited by national and international fishing fleets. The status of legislation governing both taxa is unclear and unknown by many working within the fisheries and marine sector. In Madagascar, marine turtles are fully protected from exploitation by national regulations in conjunction with a number of multilateral agreements. The numerous pieces of legislation that protect marine turtles are not coherent, regularly misunderstood and rarely enforced. Madagascar is taking steps to improve protection of marine turtles through the development of a national strategy, but it is recommended that the opportunity is also taken to improve understanding of current legislation and work more closely with local communities that consider turtle fishing a customary practice. Elasmobranchs however, receive minimal legal protection and only those listed under multilateral agreements are bound by any potential future management. Where legislation does exist to help manage elasmobranchs (eg. bycatch stipulations for foreign fishing vessels) it is incomplete and difficult to enforce. It is also recommended that Madagascar puts in place national elasmobranch legislation to help prevent their continued overfishing, especially in the face of increasing numbers of elasmobranch species on CITES and CMS. As such, both groups of species are rendered effectively unprotected and are in danger of overexploitation. With the growth and proliferation of locally managed marine areas (LMMAs) in Madagascar the potential for local communities to increase protection and management of these species should be considered, especially with the limited capacity available to monitor and enforce legislation along such a vast coastline.

Understanding spatial and temporal habitat-use patterns to protect both foraging and breeding grounds of species of concern is crucial for successful conservation. Saona Island in Del Este National Park (DENP), south-eastern Dominican Republic (DR), hosts the only major hawksbill (Eretmochelys imbricata) nesting area in the DR (100 nests yr-1, SD = 8.4, range = 93-111), with the population having been critically reduced through hunting. We satellite tracked 9 female hawksbill turtles, and present analyses of their core-use areas with respect to Marine Protected Areas (MPAs) in both their internesting and foraging areas. Kernel utilization distributions indicated that during the internesting period all turtles remained close to their nesting beaches in small home ranges in the territorial waters of the DR, mostly over the continental shelf (

The “landscape of fear” model has been proposed as a unifying concept in ecology, describing, in part, how animals behave and move about in their environment. The basic model predicts that as an animal's landscape changes from low to high risk of predation, prey species will alter their behavior to risk avoidance. However, studies investigating and evaluating the landscape of fear model across large spatial scales (tens to hundreds of thousands of square kilometers) in dynamic, open, aquatic systems involving apex predators and highly mobile prey are lacking. To address this knowledge gap, we investigated predator–prey relationships between tiger sharks (Galeocerdo cuvier) and loggerhead turtles (Caretta caretta) in the North Atlantic Ocean. This included the use of satellite tracking to examine shark and turtle distributions as well as their surfacing behaviors under varying levels of home range overlap. Our findings revealed patterns that deviated from our a priori predictions based on the landscape of fear model. Specifically, turtles did not alter their surfacing behaviors to risk avoidance when overlap in shark–turtle core home range was high. However, in areas of high overlap with turtles, sharks exhibited modified surfacing behaviors that may enhance predation opportunity. We suggest that turtles may be an important factor in determining shark distribution, whereas for turtles, other life history trade‐offs may play a larger role in defining their habitat use. We propose that these findings are a result of both biotic and physically driven factors that independently or synergistically affect predator–prey interactions in this system. These results have implications for evolutionary biology, community ecology, and wildlife conservation. Further, given the difficulty in studying highly migratory marine species, our approach and conclusions may be applied to the study of other predator–prey systems.

The management of widely dispersed marine vertebrates can be facilitated by better understanding their distribution, density, population trends and threats. Unfortunately, for some populations of sea turtle spatial and temporal data are often lacking, particularly along the Atlantic coast of Africa, a region which is considered globally important. Here we combined spatially limited monitoring data from four nesting beaches over seven seasons with an extensive ground-based coastal survey that covered 585. km of Gabon's Atlantic coast, to provide the first population assessment for the olive ridley turtle Lepidochelys olivacea. This species is currently classified as data deficient by the IUCN in the eastern Atlantic and so is considered a regional conservation priority. Whilst the logistics required to undertake such a comprehensive ground-based census were complicated, the method proved extremely effective in providing population estimates for a widely dispersed marine vertebrate and demonstrates the importance of focusing beyond intensively monitored beaches. In particular, our findings reveal that the presence of nesting activity spans almost the entirety of Gabon's coast, the density of which subsequently reveals that Gabon hosts one of the most important olive ridley rookeries in the Atlantic (2370-9814 clutches, approximating to 948-5452 breeding females per annum and a total estimate of 1422-8178 breeding females), with a significant proportion, 81. ±. 3.5% (mean. ±. 1 S.D.) of total nesting effort occurring within protected areas. These findings thus complement our existing knowledge base and further emphasise the regional and global importance of Gabon's nesting sea turtle populations.

Aim: Levels of sea turtle bycatch in the Mediterranean are thought to be unsustainable. We provide a comprehensive overview of adult green turtle (Chelonia mydas) distribution during nesting, migration and foraging phases, highlighting transitory as well as residential areas of high use to facilitate adequate protection for this long-lived, migratory species. Location: Mediterranean Sea. Methods: Thirty-four females were satellite tracked from breeding grounds in the four countries with major nesting (Cyprus, Turkey, Israel and Syria) for a total of 8521 (mean: 251) tracking days in a collaborative effort to summarize the most comprehensive set of distribution data thus far assembled for this species in the Mediterranean. Results: Ten foraging grounds are identified, with two major hotspots in Libya accounting for >50% of turtles tracked to conclusive endpoints. The coastlines of Egypt and Libya contain high densities of migrating turtles following the nesting season, particularly July-September, and likely also pre-nesting (April-June). A high-use seasonal pelagic corridor running south-west from Turkey and Cyprus to Egypt is also evident, used by >50% of all tracked turtles. Main conclusions: Bycatch levels and mortality rates for the key foraging areas and high-density seasonal pathways identified here are largely unknown and should be investigated as a priority. We recommend that the Gulf of Sirte in Libya be explored as a potential biodiversity hotspot and considered for proposal as a marine protected area (MPA). Green turtle fidelity to nesting beaches, foraging areas and migratory pathways renders them vulnerable to localized threats but enables targeted mitigation measures and protection.

Levels of sea turtle bycatch in the Mediterranean are thought to be unsustainable. We provide a comprehensive overview of adult green turtle (Chelonia mydas) distribution during nesting, migration and foraging phases, highlighting transitory as well as residential areas of high use to facilitate adequate protection for this long-lived, migratory species. Location: Mediterranean Sea. Methods: Thirty-four females were satellite tracked from breeding grounds in the four countries with major nesting (Cyprus, Turkey, Israel and Syria) for a total of 8521 (mean: 251) tracking days in a collaborative effort to summarize the most comprehensive set of distribution data thus far assembled for this species in the Mediterranean. Results: Ten foraging grounds are identified, with two major hotspots in Libya accounting for >50% of turtles tracked to conclusive endpoints. The coastlines of Egypt and Libya contain high densities of migrating turtles following the nesting season, particularly July-September, and likely also pre-nesting (April-June). A high-use seasonal pelagic corridor running south-west from Turkey and Cyprus to Egypt is also evident, used by >50% of all tracked turtles. Main conclusions: Bycatch levels and mortality rates for the key foraging areas and high-density seasonal pathways identified here are largely unknown and should be investigated as a priority. We recommend that the Gulf of Sirte in Libya be explored as a potential biodiversity hotspot and considered for proposal as a marine protected area (MPA). Green turtle fidelity to nesting beaches, foraging areas and migratory pathways renders them vulnerable to localized threats but enables targeted mitigation measures and protection.

The integration of satellite telemetry, remotely sensed environmental data, and habitat/environmental modelling has provided for a growing understanding of spatial and temporal ecology of species of conservation concern. The Republic of Cape Verde comprises the only substantial rookery for the loggerhead turtle Caretta caretta in the eastern Atlantic. A size related dichotomy in adult foraging patterns has previously been revealed for adult sea turtles from this population with a proportion of adults foraging neritically, whilst the majority forage oceanically. Here we describe observed habitat use and employ ecological niche modelling to identify suitable foraging habitats for animals utilising these two distinct behavioural strategies. We also investigate how these predicted habitat niches may alter under the influence of climate change induced oceanic temperature rises. We further contextualise our niche models with fisheries catch data and knowledge of fisheries 'hotspots' to infer threat from fisheries interaction to this population, for animals employing both strategies. Our analysis revealed repeated use of coincident oceanic habitat, over multiple seasons, by all smaller loggerhead turtles, whilst larger neritic foraging turtles occupied continental shelf waters. Modelled habitat niches were spatially distinct, and under the influence of predicted sea surface temperature rises, there was further spatial divergence of suitable habitats. Analysis of fisheries catch data highlighted that the observed and modelled habitats for oceanic and neritic loggerhead turtles could extensively interact with intensive fisheries activity within oceanic and continental shelf waters of northwest Africa. We suggest that the development and enforcement of sustainable management strategies, specifically multi-national fisheries policy, may begin to address some of these issues; however, these must be flexible and adaptive to accommodate potential range shift for this species.

To further describe movement patterns and distribution of East Pacific green turtles (Chelonia mydas agassizii) and to determine threat levels for this species within the Eastern Pacific. In order to do this we combined published data from existing flipper tagging and early satellite tracking studies with data from an additional 12 satellite tracked green turtles (1996-2006). Three of these were tracked from their foraging grounds in the Gulf of California along the east coast of the Baja California peninsula to their breeding grounds in Michoacán (1337-2928 km). In addition, three post-nesting females were satellite tracked from Colola beach, Michoacán to their foraging grounds in southern Mexico and Central America (941.3-3020 km). A further six turtles were tracked in the Gulf of California within their foraging grounds giving insights into the scale of ranging behaviour. Turtles undertaking long-distance migrations showed a tendency to follow the coastline. Turtles tracked within foraging grounds showed that foraging individuals typically ranged up to 691.6 km (maximum) from release site location. Additionally, we carried out threat analysis (using the cumulative global human impact in the Eastern Pacific) clustering pre-existing satellite tracking studies from Galapagos, Costa Rica, and data obtained from this study; this indicated that turtles foraging and nesting in Central American waters are subject to the highest anthropogenic impact. Considering that turtles from all three rookeries were found to migrate towards Central America, it is highly important to implement conservation plans in Central American coastal areas to ensure the survival of the remaining green turtles in the Eastern Pacific. Finally, by combining satellite tracking data from this and previous studies, and data of tag returns we created the best available distributional patterns for this particular sea turtle species, which emphasized that conservation measures in key areas may have positive consequences on a regional scale.

Oceanographic fronts are physical interfaces between water masses that differ in properties such as temperature, salinity, turbidity and chlorophyll a enrichment. Bio-physical coupling along fronts can lead to the development of pelagic biodiversity hotspots. A diverse range of marine vertebrates have been shown to associate with fronts, using them as foraging and migration habitats. Elucidation of the ecological significance of fronts generates a better understanding of marine ecosystem functioning, conferring opportunities to improve management of anthropogenic activities in the oceans. This study presents novel insights into the oceanographic drivers of habitat use in a population of marine turtles characterised by an oceanic-neritic foraging dichotomy. Using satellite tracking data from adult female loggerhead turtles Caretta caretta nesting at Cape Verde (n = 12), we tested the hypothesis that oceanic-foraging loggerheads associate with mesocale (10s to 100s of km) thermal fronts. We used high-resolution (1 km) composite front mapping to characterise frontal activity in the Canary Current Large Marine Ecosystem over 2 temporal scales: (1) seasonal front frequency and (2) 7 d front metrics. Our use-availability analysis indicated that oceanic loggerheads show a preference for the highly productive upwelling region between Cape Verde and mainland Africa, an area of intense frontal activity. Within the upwelling region, turtles appear to forage epipelagically around mesoscale thermal fronts, exploiting profitable foraging opportunities resulting from physical aggregation of prey.

To refine our understanding of the spatial structure of the green turtle (Chelonia mydas) populations in the South West Indian Ocean (SWIO), we analysed patterns of mitochondrial DNA (396 base pairs control region fragment) variation among 171 samples collected at five distinct locations (Kenya, Northern Mozambique, and three locations in the Republic of Seychelles: the Granitic, Amirantes, and Farquhar groups) and compared them to genetic data (n = 288), previously collected from 10 southern locations in the SWIO. We also analysed post-nesting satellite tracks (n = 4) from green turtles nesting in the Amirantes group. Pairwise comparisons of haplotype frequencies showed significant genetic differentiation amongst rookeries and suggest that the SWIO hosts two main genetic stocks of nesting green turtles that could themselves be divided in two sub-stocks that still need to be confirmed: A. the Southern Mozambique Channel, that could be composed of two sub-stocks (a1) Europa and (a2) Juan de Nova, and B. the Northern SWIO (N-SWIO) comprising two sub-stocks (b1) the Seychelles archipelago stock—SEY; and (b2) the remaining Northern SWIO rookeries. The newly revealed differentiation of the Seychelles population is supported by restricted migration of females tracked from the Amirantes group suggesting relatively limited links with other regional stocks. We hypothesize that this differentiation could be due to local and regional current patterns and to the role of the Indo-Pacific Barrier as a genetic break, enhanced during periods of sea level decrease associated with a rare but continuous flow of hatchlings and young juveniles from Western Australia.

To refine our understanding of the spatial structure of the green turtle (Chelonia mydas) populations in the South West Indian Ocean (SWIO), we analysed patterns of mitochondrial DNA (396 base pairs control region fragment) variation among 171 samples collected at five distinct locations (Kenya, Northern Mozambique, and three locations in the Republic of Seychelles: the Granitic, Amirantes, and Farquhar groups) and compared them to genetic data (n = 288), previously collected from 10 southern locations in the SWIO. We also analysed post-nesting satellite tracks (n = 4) from green turtles nesting in the Amirantes group. Pairwise comparisons of haplotype frequencies showed significant genetic differentiation amongst rookeries and suggest that the SWIO hosts two main genetic stocks of nesting green turtles that could themselves be divided in two sub-stocks that still need to be confirmed: A. the Southern Mozambique Channel, that could be composed of two sub-stocks (a1) Europa and (a2) Juan de Nova, and B. the Northern SWIO (N-SWIO) comprising two sub-stocks (b1) the Seychelles archipelago stock—SEY; and (b2) the remaining Northern SWIO rookeries. The newly revealed differentiation of the Seychelles population is supported by restricted migration of females tracked from the Amirantes group suggesting relatively limited links with other regional stocks. We hypothesize that this differentiation could be due to local and regional current patterns and to the role of the Indo-Pacific Barrier as a genetic break, enhanced during periods of sea level decrease associated with a rare but continuous flow of hatchlings and young juveniles from Western Australia.

One of the major gaps in the knowledge of sea turtle population dynamics is survival probability, in particular of juveniles, which represent the bulk of the population and whose survival has the greatest effect on population growth. One of the major global threats to sea turtles is incidental bycatch, although not all animals die in the process. This is particularly acute for the loggerhead sea turtle (Caretta caretta). Here fisheries-dependent monitoring is used to seek insights into patterns of survival at multiple Mediterranean foraging areas: north and south Adriatic, north Ionian, and the Tunisian shelf. Annual survival probability was estimated using the catch curve method. Size data of 2191 loggerhead turtles ranging from 19 to 92cm curved carapace length were converted to age according to eight age-size curves available from the Mediterranean Sea. The mean annual survival probabilities for the four areas were heterogeneous and ranged between 0.710 and 0.862. Results suggest that the survival probabilities for Mediterranean loggerheads, especially in some areas, are lower than would be expected from a healthy population. This is of particular concern for the Greek rookeries, which appear most affected by anthropogenic mortality occurring in the study areas. This supports the implementation in those areas of measures mitigating the main threats, notably bycatch. © 2014 John Wiley & Sons, Ltd.

The beaches of Jaragua National Park in the Dominican Republic are the country's last known major nesting site for the leatherback marine turtle Dermochelys coriacea. This nesting aggregation is threatened by widespread illegal egg take, and clutch relocation and artificial incubation have been carried out as protection measures since 1974. We assess the efficacy of such efforts and investigate how artificial incubation may be influencing the success and sex ratios of clutches. We compare hatching success, incubation duration and embryo mortality in in-situ clutches (n = 43) with those incubated artificially at sites in the east and west of the Park (n = 35 and n = 31, respectively). Our results show that in the west, artificial incubation significantly decreases hatching success in clutches. In the east the duration of incubation is increased, which we predict would result in an increase in the number of males from these clutches. Clutch relocation is currently the only viable conservation option for clutches on eastern beaches because of illegal egg take but action is needed to ensure that the natural sex ratio is not distorted. However, on the western beaches in situ clutch incubation seems possible through beach protection. Further community engagement and enforcement are required to improve conservation measures at eastern beaches if long-term, less sustainable intervention is to be avoided. Copyright © Fauna & Flora International 2014.

Shark take, driven by vast demand for meat and fins, is increasing. We set out to gain insights into the impact of small-scale longline fisheries in Peru. Onboard observers were used to document catch from 145 longline fishing trips (1668 fishing days) originating from Ilo, southern Peru. Fishing effort is divided into two seasons: targeting dolphinfish (Coryphaena hippurus; December to February) and sharks (March to November). A total of 16,610 sharks were observed caught, with 11,166 identified to species level. of these, 70.6% were blue sharks (Prionace glauca), 28.4% short-fin mako sharks (Isurus oxyrinchus), and 1% were other species (including thresher (Alopias vulpinus), hammerhead (Sphyrna zygaena), porbeagle (Lamnus nasus), and other Carcharhinidae species (Carcharhinus brachyurus, Carcharhinus falciformis, Galeorhinus galeus). Mean ± SD catch per unit effort of 33.6 ± 10.9 sharks per 1000 hooks was calculated for the shark season and 1.9 ± 3.1 sharks per 1000 hooks were caught in the dolphinfish season. An average of 83.7% of sharks caught (74.7% blue sharks; 93.3% mako sharks) were deemed sexually immature and under the legal minimum landing size, which for species exhibiting k-selected life history traits can result in susceptibility to over exploitation. As these growing fisheries operate along the entire Peruvian coast and may catch millions of sharks per annum, we conclude that their continued expansion, along with ineffective legislative approaches resulting in removal of immature individuals, has the potential to threaten the sustainability of the fishery, its target species, and ecosystem. There is a need for additional monitoring and research to inform novel management strategies for sharks while maintaining fisher livelihoods. © 2014 the Authors.

Concern has been expressed over future biogeographical expansion and habitat capitalization by species of the phylum Cnidaria, as this may have negative implications on human activities and ecosystems. There is, however, a paucity of knowledge and understanding of jellyfish ecology, in particular species distribution and seasonality. Recent studies in the UK have principally focused on the Celtic, Irish and North Seas, but all in isolation. In this study we analyse data from a publicly-driven sightings scheme across UK coastal waters (2003-2011; 9 years), with the aim of increasing knowledge on spatial and temporal patterns and trends. We describe inter-annual variability, seasonality and patterns of spatial distribution, and compare these with existing historic literature. Although incidentally-collected data lack quantification of effort, we suggest that with appropriate data management and interpretation, publicly-driven, citizen-science-based, recording schemes can provide for large-scale (spatial and temporal) coverage that would otherwise be logistically and financially unattainable. These schemes may also contribute to baseline data from which future changes in patterns or trends might be identified. We further suggest that findings from such schemes may be strengthened by the inclusion of some element of effort-corrected data collection.

The use of electronic tagging (e.g. acoustic, archival and satellite telemetry) to study the behavior and ecology of aquatic animals has increased dramatically over the past decade. As scientists continue to use these tools, it is inevitable that other researchers and the public at-large will encounter animals carrying such tags with increasing frequency. If the animals appear burdened or injured by the tag (e.g. showing signs of trauma), or if the tag is functionally impaired (e.g. cracked or severely biofouled), these encounters have the potential to generate conflict with various wildlife stakeholders (e.g. tourists/operators, divers, fishers, hunters) that can negatively affect research efforts and undermine conservation work. Yet, these encounters also present an unparalleled opportunity to advance the field of biotelemetry by improving animal welfare, tagging technology and practices, while also gaining the trust and support of wildlife stakeholders. Therefore, as scientists, it is important to consider the fate of our electronic tags. Here we consider tagged animals as encountered by different user groups and discuss the potential steps and recommendations that scientists can take to improve tagging techniques and animal welfare as a result. We also discuss interactions with stakeholders and the manifold benefits if such interactions are taken into account and embraced. We examine the situation where a researcher encounters, and is able and trained to handle a previously tagged animal equipped with a functionally impaired tag and/or the animal is exhibiting signs of burden due to the tag. We generate a decision tree for scientists faced with such a scenario and discuss the best course of action, whereas such a situation was relatively unlikely in the past, but is now a reality in all aquatic animal tagging studies. The framework in which these issues are discussed is novel and failure to address them can significantly impede advances in the development and use of biotelemetry and even one's ability to conduct research. It is our hope that our essay stimulates further discourse, debate, technological improvements and consideration of the fate of electronic tagging.

Population monitoring is an essential part of evaluating the effectiveness of management interventions for conservation. Coastal breeding aggregations of marine vertebrate species that come ashore to pup or nest provide an opportunistic window of observation into otherwise widely dispersed populations. Green turtle (Chelonia mydas) nesting on the north and west coasts of northern Cyprus has been monitored consistently and exhaustively since 1993, with an intensive saturation tagging programme running at one key site for the same duration. This historically depleted nesting population is showing signs of recovery, possibly in response to nest protection approaching two decades, with increasing nest numbers and rising levels of recruitment. Strong correlation between year-to-year magnitude of nesting and the proportion of new breeders in the nesting cohort implies that recruitment of new individuals to the breeding population is an important driver of this recovery trend. Recent changes in fishing activities may be impacting the local juvenile neritic stage, however, which may hinder this potential recovery. Individuals returning to breed after two years laid fewer clutches than those returning after three or four years, demonstrating a trade-off between remigration interval and breeding output. Average clutch frequencies have remained stable around a median of three clutches a year per female despite the demographic shift towards new nesters, which typically lay fewer clutches in their first season. We show that where local fecundity has been adequately assessed, the use of average clutch frequencies can be a reliable method for deriving nester abundance from nest counts. Index sites where individual-based monitoring is possible will be important in monitoring long-term climate driven changes in reproductive rates.

Management of species of conservation concern requires knowledge of demographic parameters, such as rates of recruitment, survival, and growth. In the Caribbean, hawksbill turtles (Eretmochelys imbricata) have been historically exploited in huge numbers to satisfy trade in their shells and meat. In the present study, we estimated growth rate of juvenile hawksbill turtles around Anegada, British Virgin Islands, using capture-mark-recapture of 59 turtles over periods of up to 649 days. Turtles were recaptured up to six times, having moved up to 5.9 km from the release location. Across all sizes, turtles grew at an average rate of 9.3 cm year-1 (range 2.3-20.3 cm year-1), and gained mass at an average of 3.9 kg year-1 (range 850 g-16.1 kg year-1). Carapace length was a significant predictor of growth rate and mass gain, but there was no relationship between either variable and sea surface temperature. These are among the fastest rates of growth reported for this species, with seven turtles growing at a rate that would increase their body size by more than half per year (51-69% increase in body length). This study also demonstrates the importance of shallow water reef systems for the developmental habitat for juvenile hawksbill turtles. Although growth rates for posthatching turtles in the pelagic, and turtles larger than 61 cm, are not known for this population, the implications of this study are that Caribbean hawksbill turtles in some areas may reach body sizes suggesting sexual maturity in less time than previously considered. In the present study, we estimated growth rate of juvenile hawksbill turtles around Anegada, British Virgin Islands, using capture-mark-recapture of 59 turtles over periods of up to 649 days. Across all sizes, turtles grew at an average rate of 9.3 cm per year (range 2.3-20.3 cm year-1), and gained mass at an average of 3.9 kg year-1 (range 850 g-16.1 kg year-1). These are among the fastest rates of growth reported for this species, with seven turtles growing at a rate that would increase their body size by more than half per year (51-69% increase in body length). © 2014 the Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Genetic markers have been widely used in marine turtles to assess population structuring and origin of individuals in common feeding grounds, which are key elements for understanding their ecology and for developing conservation strategies. However, these analyses are very sensitive to missing information, especially from abundant nesting sites. Kyparissia Bay (western Greece) hosts the second largest Mediterranean nesting aggregation of the loggerhead turtle (Caretta caretta), but the genetic profile of this nesting site has not, as yet, been described using the extended version of the historically used mitochondrial DNA (mtDNA) marker. This marker was genotyped for 36 individuals nesting at Kyparissia Bay and haplotype frequencies obtained were compared with published data from other Mediterranean nesting sites. The results confirmed the connection between Kyparissia and other western Greek nesting sites and the isolation of this western Greek group from other Mediterranean nesting areas. As a consequence of this isolation, this abundant group of nesting aggregations (almost 30% of the Mediterranean stock) is not likely to significantly contribute to the recovery of other declining Mediterranean units. © 2014 CSIC.

Long-distance dispersal and ontogenetic shifts in habitat use are characteristic of numerous marine species and have important ecological, evolutionary, and management implications. These processes, however, are often challenging to study due to the vast areas involved. We used genetic markers and simulations of physical transport within an ocean circulation model to gain understanding into the origin of juvenile hawksbill sea turtles (. Eretmochelys imbricata) found at Ascension Island, a foraging ground that is thousands of kilometers from known nesting beaches. Regional origin of genetic markers suggests that turtles are from Western Atlantic (86%) and Eastern Atlantic (14%) rookeries. In contrast, numerical simulations of transport by ocean currents suggest that passive dispersal from the western sources would be negligible and instead would primarily be from the East, involving rookeries along Western Africa (i.e. Principe Island) and, potentially, from as far as the Indian Ocean (e.g. Mayotte and the Seychelles). Given that genetic analysis identified the presence of a haplotype endemic to Brazilian hawksbill rookeries at Ascension, we examined the possible role of swimming behavior by juvenile hawksbills from NE Brazil on their current-borne transport to Ascension Island by performing numerical experiments in which swimming behavior was simulated for virtual particles (simulated turtles). We found that oriented swimming substantially influenced the distribution of particles, greatly altering the proportion of particles dispersing into the North Atlantic and South Atlantic. Assigning location-dependent orientation behavior to particles allowed them to reach Ascension Island, remain in favorable temperatures, encounter productive foraging areas, and return to the vicinity of their natal site. The age at first arrival to Ascension (4.5-5.5. years) of these particles corresponded well to estimates of hawksbill age based on their size. Our findings suggest that ocean currents and swimming behavior play an important role in the oceanic ecology of sea turtles and other marine animals. © 2013 Elsevier B.V.

Large oceanic migrants play important roles in ecosystems, yet many species are of conservation concern as a result of anthropogenic threats, of which incidental capture by fisheries is frequently identified. The last large populations of the leatherback turtle, Dermochelys coriacea, occur in the Atlantic Ocean, but interactions with industrial fisheries could jeopardize recent positive population trends, making bycatch mitigation a priority. Here, we perform the first pan-Atlantic analysis of spatio-temporal distribution of the leatherback turtle and ascertain overlap with longline fishing effort. Data suggest that the Atlantic probably consists of two regional management units: northern and southern (the latter including turtles breeding in South Africa). Although turtles and fisheries show highly diverse distributions, we highlight nine areas of high susceptibility to potential bycatch (four in the northern Atlantic and five in the southern/equatorial Atlantic) that are worthy of further targeted investigation and mitigation. These are reinforced by reports of leatherback bycatch at eight of these sites. International collaborative efforts are needed, especially from nations hosting regions where susceptibility to bycatch is likely to be high within their exclusive economic zone (northern Atlantic: Cape Verde, Gambia, Guinea Bissau, Mauritania, Senegal, Spain, USA and Western Sahara; southern Atlantic: Angola, Brazil, Namibia and UK) and from nations fishing in these high-susceptibility areas, including those located in international waters.

Aim: We provide a global assessment of the current legal direct take of marine turtles, including the scale and species breakdown at country level, and investigate the significance of legal take to marine turtle populations within the wider context of global threats. Location: World-wide. Methods: We undertook a comprehensive review of the literature (>500 publications) and contacted over 150 in-country experts to collate data for countries that permit the legal take of marine turtles (as of 1 January 2013). Current annual take for each country and species was estimated, and estimates were generated for the 1980s, 1990s and 2000s. Results: Currently, 42 countries and territories permit direct take of turtles and collectively take in excess of 42,000turtles per year, the majority of which (>80%) are green turtles Chelonia mydas (Linnaeus 1758). Ten countries account for more than 90% of legal take each year with Papua New Guinea (36.1%) and Nicaragua (22.3%) accounting for more than half of the total global take. Since 1980, we estimate that more than 2million turtles have been legally taken in these countries, with current levels

Temperature can have a profound effect on the phenotype of reptilian offspring, yet the bulk of current research considers the effects of constant incubation temperatures on offspring morphology, with few studies examining the natural thermal variance that occurs in the wild. Over two consecutive nesting seasons, we placed temperature data loggers in 57 naturally incubating clutches of loggerhead sea turtles Caretta caretta and found that greater diel thermal variance during incubation significantly reduced offspring mass, potentially reducing survival of hatchlings during their journey from the nest to offshore waters and beyond. With predicted scenarios of climate change, behavioral plasticity in nest site selection may be key for the survival of ectothermic species, particularly those with temperature-dependent sex determination.

Protected areas are considered essential elements for global biodiversity conservation. They may not necessarily result in an effective conservation of resources in developing countries due to lack of funding for management and enforcement. In addition, poor governance aligned with conflicts of economic interests related to their use can further threaten their integrity and persistence. In the Dominican Republic, the western beaches of the Jaragua National Park (JNP), a protected area which is also part of a UNESCO Biosphere Reserve, have been proposed for development using a mass-tourism model. One of the most charismatic species found in this area is the leatherback turtle (Dermochelys coriacea). In the present study, we assess hatching success, and factors affecting it, to determine the reproductive value across the area for the leatherback turtle. The main factors found driving hatching success at the study beaches are beach sector, incubation duration, date of lay and clutch size. Our results show that clutches in La Cueva (located in the buffer zone of the park) and Bahía de las Águilas (located inside the limits of the park) have an unusually high hatching success (~75 %) for this species, highlighting the importance of increasing protection efforts at these sites. We strongly recommend including La Cueva inside the limits of the JNP. © 2014 Springer Science+Business Media Dordrecht.

The temperate waters of the North-Eastern Atlantic have a long history of maritime resource richness and, as a result, the European Union is endeavouring to maintain regional productivity and biodiversity. At the intersection of these aims lies potential conflict, signalling the need for integrated, cross-border management approaches. This paper focuses on the marine megafauna of the region. This guild of consumers was formerly abundant, but is now depleted and protected under various national and international legislative structures. We present a meta-analysis of available megafauna datasets using presence-only distribution models to characterise suitable habitat and identify spatially-important regions within the English Channel and southern bight of the North Sea. The integration of studies from dedicated and opportunistic observer programmes in the United Kingdom and France provide a valuable perspective on the spatial and seasonal distribution of various taxonomic groups, including large pelagic fishes and sharks, marine mammals, seabirds and marine turtles. The Western English Channel emerged as a hotspot of biodiversity for megafauna, while species richness was low in the Eastern English Channel. Spatial conservation planning is complicated by the highly mobile nature of marine megafauna, however they are important components of the marine environment and understanding their distribution is a first crucial step toward their inclusion into marine ecosystem management.

Nesting by three species of marine turtles persists in the Dominican Republic, despite historic threats and long-term population decline. We conducted a genetic survey of marine turtles in the Dominican Republic in order to link them with other rookeries around the Caribbean. We sequenced a 740bp fragment of the control region of the mitochondrial DNA of 92 samples from three marine turtle species [hawksbill (n = 48), green (n = 2) and leatherback (n = 42)], and incorporated published data from other nesting populations and foraging grounds. The leatherback turtle (Dermochelys coriacea) in the Dominican Republic appeared to be isolated from Awala-Yalimapo, Cayenne, Trinidad and St. Croix but connected with other Caribbean populations. Two distinct nesting populations of hawksbill turtles (Eremochelys imbricata) were detected in the Dominican Republic and exhibited interesting patterns of connectivity with other nesting sites and juvenile and adult male foraging aggregations. The green sea turtle (Chelonia mydas) has almost been extirpated from the Dominican Republic and limited inference could be made from our samples. Finally, results were compared with Lagrangian drifting buoys and published Lagrangian virtual particles that travelled through the Dominican Republic and Caribbean waters. Conservation implications of sink-source effects or genetic isolation derived from these complex inter-connections are discussed for each species and population. © 2013 Carreras et al.

Much is still to be learned about the spatial ecology of foraging marine turtles, especially for juveniles and adult males which have received comparatively little attention. Additionally, there is a paucity of ecological information on growth rates, size and age at maturity, and sex ratios at different life stages; data vital for successful population modelling. Here, we present results of a long-term (2002-2011) study on the movements, residency, growth and sex ratio of loggerhead turtles (Caretta caretta) in Amvrakikos Gulf (39°0′N 21°0′E), Greece, using satellite telemetry (N = 8) and ongoing capture-mark-recapture (CMR; N = 300 individuals). Individuals encountered at sea ranged from large juvenile to adult (46. 2-91. 5 cm straight carapace length) and demonstrated growth rates within published norms (44 % of captures above 65 cm straight carapace length), compared to region-wide female-biased hatchling production, indicating sex-biased survival or possible behavioural drivers for likelihood of capture in the region. Satellite tracking confirmed that some turtles establish discrete, protracted periods of residency spanning more than 1 year, whilst others migrated away from the site. These findings are underlined by CMR results with individual capture histories spanning up to 7 years, and only 18 % of individuals being recaptured. © 2012 Springer-Verlag Berlin Heidelberg.

Evolutionary theory predicts that male and female offspring should be produced at a 1:1 ratio, but this may rarely be the case for species in which sex is determined during incubation by temperature, such as marine turtles. Estimates of primary sex ratio suggest that marine turtle sex ratios are highly skewed, with up to 9 females per male. We captured juvenile hawksbill turtles Eretmochelys imbricata in waters around Anegada, British Virgin Islands, a regionally important foraging aggregation, and analysed concentrations of plasma testosterone and oestradiol- 17β from 62 turtles to estimate sex ratio. There were 2.4 to 7.7 times more females than males. Testosterone concentrations correlated with sampling date and sea surface temperature (SST), with higher con centrations in the late summer when SST was highest, suggesting that assigning sex through threshold values of sex hormones must be carried out cautiously. The sex ratio in the juvenile foraging aggregation around Anegada is more male biased than at other locations, suggesting that turtles at Anegada have resilience against feminising effects of climate change. Future work should (1) integrate the relative contributions of different genetic stocks to foraging aggregations and (2) investigate the annual and seasonal cycles of sex hormones, and differences among individuals and life history stages. © Inter-Research 2013.

From 1998 to 2008, 68 adult female loggerhead sea turtles (Caretta caretta) were instrumented with platform transmitter terminals at nesting beaches in Georgia, North Carolina (NC) and South Carolina (SC) on the East Coast of the United States of America (30°48′N, 81°28′W to 33°51′N, 77°59′W). The majority of post-nesting loggerheads (N = 42, 62 %) migrated to foraging habitats in the Mid-Atlantic Bight during May-October, with a subsequent migration occurring during November-March to foraging habitats south of Cape Hatteras, NC. Nine (13 %) loggerheads initially foraged in the near-shore, coastal areas of the South Atlantic Bight, but moved to offshore habitats-closer to the Gulf Stream-during November-March, while fourteen (21 %) loggerheads remained in foraging areas along the mid-continental shelf off of the eastern coast of Florida and/or continued southward to Florida Bay and the Bahamas. The present study delineates important, post-nesting foraging habitats and migration corridors where loggerheads may interact with commercial fisheries-providing managers opportunities to develop and implement optimally effective conservation actions for the recovery of this threatened species. © 2013 Springer-Verlag Berlin Heidelberg.

There is a paucity of information on the presence and nesting of green turtles, Chelonia mydas, in Kuwait, and known nesting habitats have been altered in recent years. Through beach monitoring and satellite telemetry, we determined that green turtle nesting is now limited to Qaru Island with 1-5 turtles nesting annually and that foraging habitats occur along the northern shore of Failaka Island (n=2 turtles) and coastal region of central Saudi Arabia (n=1 turtle). Foraging habitat in Kuwait overlaps with a coastal trap-fishery, raising concerns for the conservation of this depleted population. © 2013 Chelonian Research Foundation.

Many important issues in conservation biology are more clearly visible on islands than on continental mainlands. This chapter summarizes a few of the key topics that concern island managers worldwide, with exemplary habitat case studies from the islands. The chapter considers primarily the land-breeding vertebrate faunas of islands, but only because there are fewer consistent and comparable databases available on plants and invertebrates. Insular species are ecologically naive to exotic competitors, predators and parasites, or imperilled by the loss of native pollinators, seed dispersers and other mutualists. In order to conserve the marvellous diversity and the natural characters of island biota, the challenge is to manage fragile, insular assemblages successfully. That means attempting to minimize intense habitat destruction and alteration, such as logging, agricultural conversion and urbanization, and reducing the threat from ecologically novel, exotic species while maintaining or replacing natural, ecological conditions that shaped the evolution of island life. © 2013 John Wiley & Sons, Ltd.

Species with temperature-dependent sex determination (TSD) are likely to be impacted by climate change. There is a paucity of data on the contemporary sex ratios of offspring produced by regional marine turtle populations. The lack of such information inhibits the ability of researchers to accurately predict how future meteorological and climate-driven changes may affect turtle populations. Moreover, these data are integral for the development of regional and global recovery plans for declining turtle populations. We estimate offspring sex ratios for the loggerhead turtle Caretta caretta at a range of beaches on the Mediterranean island of Cyprus over a 10 yr period (1997 to 2006; 40 beaches, 628 clutches, 29402 hatchlings). Based on hatchling sex determination, we found the pivotal incubation temperature (the temperature at which a 50:50 sex ratio occurs) to be 28.9°C, and the pivotal incubation duration to be 56.3 d. From the incubation durations of over 628 in situ clutches laid on different beaches, we estimate that 89% of the offspring produced from these clutches were female. There was, however, both inter-annual (74 to 95% female) and inter-beach (58-98% female) variability in mean offspring sex ratios. These findings highlight the need for wide-scale, long-term monitoring of primary sex ratios in order to accurately predict the likely impacts of climate change. Despite spatial and temporal variation in offspring sex ratios produced, male hatchlings are certainly in the minority in Cyprus. It is therefore highly likely that beaches producing males will become increasingly critical habitats for successful clutch incubation in the face of predicted rising temperatures. © Inter-Research 2013.

Hazel dormice, Muscardinus avellanarius (Rodentia: Gliridae) are vulnerable to habitat loss and fragmentation, and thus protected by European Directives. We isolated hazel dormouse microsatellite sequences from enriched genomic libraries to facilitate conservation-focussed research, such as population genetics, regarding this threatened species. Fifty-three primer sets were designed from 51 newly isolated loci. Additionally, we redesigned and tested nine primer sets from previously-published hazel dormouse microsatellite sequences. These 62 marker sets were initially tested in eight unrelated individuals. Thirty-nine loci, which were polymorphic and amplified in >88 % of these samples (extracted from hair), were then genotyped and characterised in 22-26 individuals. of these, 26 autosomal loci (18 new and eight published) adhered to Hardy-Weinberg equilibrium (p ≤ 0.05) and displayed an estimated null allele frequency of

Leatherback turtles migrate across the jurisdictions of multiple sovereign states and present complex challenges to those responsible for their conservation. Concern for marine turtles has led to their protection under range state legislation and protective listing under a suite of multilateral environmental agreements. Evidence suggests that a distinct, reproductive sub-population of leatherback turtles is shared amongst a number of northern Caribbean range states, including the UK overseas territories (UKOTs) of Anguilla and the British Virgin Islands (BVI). The post-nesting movements of three female leatherbacks were tracked after they nested in Anguilla (n=1, tracked for 228 days) and the BVI (n=2, tracked for 12 and 13 days, respectively). These turtles used territories of multiple range states, with the leatherback tracked from Anguilla also migrating through high seas to foraging grounds in Canadian waters. In addition, a review of regional leatherback flipper tag return records helps define the range of this northern Caribbean nesting population (NCNP), which appears to be in recovery in some range states. While national legislation and conservation efforts appear to have contributed to these population recoveries, most relevant MEAs appear to have played little or no role. However, opportunities for constructive dialogue between NCNP range states exist under the Cartagena Convention the United Nations Convention on the Law of the Sea and the International Commission for the Conservation of Atlantic Tuna (ICCAT). UKOT conservation managers would, therefore, be justified in prioritising unilateral leatherback conservation action, and multilateral efforts through the Cartagena convention and regional fishery management mechanisms, over potentially costly accessions to additional MEAs.

Small-scale fisheries (SSF) account for around half of the world's marine and inland fisheries, but their impact on the marine environment is usually under-estimated owing to difficulties in monitoring and regulation. Successful management of mixed SSF requires holistic approaches that sustainably exploit target species, consider non-target species and maintain fisher livelihoods. For two years, we studied the marine turtle fishery in the Turks and Caicos Islands (TCI) in the Wider Caribbean Region, where the main export fisheries are queen conch (Strombus gigas) and the spiny lobster (Panulirus argus); with fin-fish, green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) taken for domestic consumption. We evaluate the turtle harvest in relation to the other fisheries and recommend legislation and management alternatives. We demonstrate the connectivity between multi-species fisheries and artisanal turtle capture: with increasing lobster catch-per-unit-effort (CPUE), hawksbill catch increased whilst green turtle catch decreased. With increasing conch CPUE, hawksbill catch declined and there was no demonstrable effect on green turtle catch. We estimate 176-324 green and 114-277 hawksbill turtles are harvested annually in TCI: the largest documented legal hawksbill fishery in the western Atlantic. of particular concern is the capture of adult turtles. Current legislation focuses take on larger individuals that are key to population maintenance. Considering these data we recommend the introduction of maximum size limits for both species and a closed season on hawksbill take during the lobster fishing season. Our results highlight the need to manage turtles as part of a broader approach to SSF management. © 2013 Elsevier Ltd.

Multiple paternity is extremely common in natural populations of almost all reptiles studied to date, suggesting that pay-offs from polyandrous mating systems are important in these taxonomic groups. However, strong evidence in support of direct or indirect benefits to females is scarce. We examined the relationship between polyandry and components of female reproductive success and offspring fitness in the promiscuous green turtle (Chelonia mydas), a species that exhibits highly variable levels of multiple paternity. We did not detect any clear fitness benefits to polyandrous females in this study, and we discuss the potential of sexual conflict to influence female mating patterns in marine turtles. We show that polyandrous females produce significantly smaller clutches than monandrous females, highlighting a potential cost to polyandry in green turtles. Furthermore, multiple paternity was more common in returning females (recorded breeding in a previous season) than in females nesting for the first time at our study site, possibly reflecting increased encounter rates with males or sperm storage across breeding seasons. Our results reveal potentially complex influences of female traits, environment, and mating strategy on components of reproductive success, and we discuss the challenges associated with unraveling the costs and benefits of multiple mating in natural populations. © 2013 the Author. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.

Aim: Knowledge and understanding of marine vertebrate spatial ecology are required to identify sources of threat and highlight areas for conservation. Olive ridley sea turtles Lepidochelys olivacea are in decline in some regions, and data for the Eastern Atlantic are sparse. Here, we seek to describe observed, and potential, post-nesting habitats for this species in the southeast Atlantic. We contextualize these with fisheries catch data to identify areas of potential threat from fisheries interaction for this species. Location: West coast of Africa, southeast Atlantic. Methods: We tracked 21 female olive ridley turtles, from two nesting sites, between 2007 and 2010. We used ensemble ecological niche modelling, integrated with knowledge on the physical and biological oceanographic environment, to identify regions where environmental variables exist that may be critical in defining post-nesting habitats for this species. We further integrate fisheries catch data to contextualize potential threat from fisheries. Results: We describe key areas of observed, and potential, olive ridley turtle occurrence at sea, and reveal that there was considerable overlap of these conspecifics, from two distinct nesting regions, within the Angolan exclusive economic zone (EEZ). With the inclusion of fisheries catch data for the region, we highlight areas that have the potential for conflict with fishing activities known to result in bycatch. Main conclusions: This study demonstrates that it is imperative that marine conservation policy recognizes the spatial extent of highly migratory species with expansive ranges. It also highlights that deficiencies exist in current knowledge of bycatch, both in gear specificity and in catch per unit effort. With integration of vessel monitoring system (VMS) data and those on fisheries catch, knowledge and understanding of bycatch may be improved, and this will ultimately facilitate development of appropriate management strategies and long-term sustainability of fisheries and their supporting ecosystems. © 2013 John Wiley & Sons Ltd.

Satellite transmitters were deployed on ten green turtles (Chelonia mydas) nesting in Rekawa Sanctuary (RS-80.851°E 6.045°N), Sri Lanka, during 2006 and 2007 to determine inter-nesting and migratory behaviours and foraging habitats. Nine turtles subsequently nested at RS and demonstrated two inter-nesting strategies linked to the location of their residence sites. Three turtles used local shallow coastal sites within 60 km of RS during some or all of their inter-nesting periods and then returned to and settled at these sites on completion of their breeding seasons. In contrast, five individuals spent inter-nesting periods proximate to RS and then migrated to and settled at distant (>350 km) shallow coastal residence sites. Another turtle also spent inter-nesting periods proximate to RS and then migrated to a distant oceanic atoll and made forays into oceanic waters for 42 days before transmissions ceased. This behavioural plasticity informs conservation management beyond protection at the nesting beach. © 2013 Springer-Verlag Berlin Heidelberg.

In recent years, information about the movements and timing of migration by male sea turtles has begun to be unraveled. Here, we present the first satellite tracking of male loggerhead sea turtles (Caretta caretta) in the eastern Atlantic. Satellite linked transmitters were attached to five adult males, captured in the near shore waters off Boavista, Republic of Cape Verde. This archipelago hosts the single most important breeding site of loggerhead turtles in the eastern Atlantic. Animals were tracked for periods ranging between 48 and 537. days, including a probable annual remigration to the vicinity of the nesting ground for one turtle. Males showed a variety of movement patterns both during and after the breeding season. of three males that transmitted for 85, 329 and 537. days, two (the smallest) migrated east and remained in oceanic waters for the tracking period and another (larger turtle) migrated 810. km northeast, to neritic waters off the coast of Mauritania, Western Africa. Results suggest males may show the same size-linked dichotomy in migratory strategies, as has been shown for females from this population. © 2013 Elsevier B.V.

It has become widely recognized that a large gap exists in the global knowledge of fisheries due to the continued oversight of the small-scale sector. For populations of marine turtles restricted to the eastern Mediterranean, bycatch in small-scale fisheries is a concern. By using North Cyprus as a case study for the region, we used anthropological methods to estimate the magnitude of marine turtle bycatch, while presenting novel information on the marine turtle life stages using the coast and profiling the fishery itself. Our analyses suggest that as many as 1000 turtles may be caught annually by this fishery with an estimated mortality rate of 60%. Trammel nets were the main cause of marine turtle bycatch. Strandings coincided with setting of trammel nets that target siganids (Siganus luridus and Siganus rivulatus) and the majority of bycatch registered by fishers were caught in these gear types. We demonstrate a relatively simple approach to evaluating marine turtle bycatch, providing information that will allow local authorities and conservation groups to direct further research and possible mitigation measures. © 2013 Chelonian Research Foundation.

Accurate estimates of abundance are fundamental to the conservation of threatened species, but are often difficult to obtain directly. Population size assessments of marine turtles are often based on counts of nests, which are then related to abundance using the mean number of clutches laid by individuals within a season. Due to low re-encounter probabilities, clutch frequency has proven difficult to estimate reliably, particularly for large populations that make a major contribution to global stock assessments. We use a combination of VHF radio-telemetry and Argos-linked Fastloc™ GPS devices to improve clutch frequency estimates for one of the world's largest green turtle rookeries at Ascension Island. Females fitted with VHF tags at the start of the season (. n=. 40) were re-encountered with a probability of 85% and laid a minimum average of 5.8 clutches. Three of these turtles were fitted with VHF and GPS devices and using the data collected by the latter, were found to lay an average of 6.3 clutches. GPS-telemetry detected emergences observed using radio-telemetry, and confirmed that some radio-tagged turtles laid again after their last observed emergence. Correcting for missed nesting events yielded a mean clutch frequency of 6.3, more than doubling the previous estimate of 3.0 for this population. Applying this revised assessment to annual nest counts reduces the estimated size of this population by 52%. Conventional tagging approaches may considerably underestimate annual fecundity of turtles, resulting in inflated population size estimates. We call for urgent reassessment of baseline abundance values for regionally important populations. © 2013 Elsevier Ltd.

There is growing awareness that small-scale fisheries may have large impacts on threatened marine fauna. Bycatch of small cetaceans by the Peruvian small-scale driftnet fleet results in the deaths of thousands of animals annually. We sought to assess the effectiveness of acoustic alarms (pingers) for reducing the incidental capture of dolphins and porpoises by this fleet. Forty-three experimental trips (156 fishing sets) and 47 control trips (195 fishing sets) out of Salaverry Port, northern Peru, were observed from April 2009 to August 2011. Twenty-two percent of control sets captured small cetaceans (67 individuals) and 16% of experimental sets had captures of small cetaceans (33 individuals). The bycatch rate of experimental sets was 0.50 individuals km-2h-1, whereas for control sets the rate was 0.80 individuals km-2h-1. This 37% reduction in bycatch rate suggests that pingers may be effective in reducing the bycatch of small cetaceans in this fishery. Catch rates of the fishery's target shark and ray species were unchanged. Given the vast size of this fishery and its current levels of bycatch of small cetaceans (>Â 10,000 individuals annually), even the modest declines in bycatch we observed could result in reductions in mortality of hundreds or thousands of small cetaceans per annum. Challenges, including increased costs, to large-scale utilization of pingers have yet to be overcome. The harpooning of dolphins for use as bait will also need to be addressed for further reductions in dolphin and porpoise bycatch and mortality to be achievable. © 2013 Fauna & Flora International.

We describe a new species of chameleon, Trioceros kinangopensis sp. nov. from Kinangop Peak in the Aberdare mountains, central highlands of Kenya. The proposed new species is morphologically and genetically distinct from other member of the bitaeniatus-group. It is morphologically most similar to T. schubotzi but differs in the lack of sexual size dimorphism, smaller-sized females, smoother, less angular canthus rostrales, smaller scales on the temporal region and a bright orange gular crest in males. Mitochondrial DNA indicates that the proposed new taxon is a distinct lineage that is closely related to T. nyirit and T. schubotzi. The distribution of T. kinangopensis sp. nov. appears to be restricted to the afroalpine zone in vicintiy of Kinangop Peak and fires may pose a serious threat to the long-term survival of this species. Copyright © 2012 · Magnolia Press.

Seabirds are well monitored and protected at their breeding grounds but spend most of their life at sea, where they are less well monitored and afforded little protection. In an attempt to address this dichotomy, attention has been directed toward establishing a network of marine reserves for seabirds, based largely on information from at-sea surveys and/or biotelemetry studies. Nevertheless, these approaches are costly, are typically only available for a limited number of locations, and not suitable for species that have either poor at-sea detectability or are unable to carry tracking devices. Here we develop a technique to identify important areas for breeding seabirds based on at-sea projections from colonies. Synthesising data from colony surveys with detailed information on population dynamics, foraging ecology and near-colony behaviour, we project colony-specific foraging distributions of the Northern gannet (Morus bassanus) at colonies in the UK, Ireland and France. We test the ability of our models to identify at-sea hotspots through comparison with existing data from biotelemetry studies and at-sea visual surveys. These models show a positive spatial correlation with one of the most intensive at-sea seabird survey datasets. While there are limitations to estimating at-sea distributions of seabirds, implemented appropriately, we propose they could prove useful in identifying potential Marine Protected Areas for seabirds. Moreover, these models could be developed to suit a range of species or whole communities and provide a theoretical framework for the study of factors such as colony size regulation. © 2012 Elsevier Ltd. All rights reserved.

Seabirds are well monitored and protected at their breeding grounds but spend most of their life at sea, where they are less well monitored and afforded little protection. In an attempt to address this dichotomy, attention has been directed toward establishing a network of marine reserves for seabirds, based largely on information from at-sea surveys and/or biotelemetry studies. Nevertheless, these approaches are costly, are typically only available for a limited number of locations, and not suitable for species that have either poor at-sea detectability or are unable to carry tracking devices. Here we develop a technique to identify important areas for breeding seabirds based on at-sea projections from colonies. Synthesising data from colony surveys with detailed information on population dynamics, foraging ecology and near-colony behaviour, we project colony-specific foraging distributions of the Northern gannet (. Morus bassanus) at colonies in the UK, Ireland and France. We test the ability of our models to identify at-sea hotspots through comparison with existing data from biotelemetry studies and at-sea visual surveys. These models show a positive spatial correlation with one of the most intensive at-sea seabird survey datasets. While there are limitations to estimating at-sea distributions of seabirds, implemented appropriately, we propose they could prove useful in identifying potential Marine Protected Areas for seabirds. Moreover, these models could be developed to suit a range of species or whole communities and provide a theoretical framework for the study of factors such as colony size regulation. © 2012 Elsevier Ltd.

The main nesting area for loggerhead turtles in the eastern Atlantic is in the Cape Verde Islands, largely restricted to the island of Boa Vista. Extensive monitoring demonstrated a globally significant population for the species despite a sustained high level of anthropogenic take of nesting females for local consumption. Through an extensive stratified monitoring program across the island in the seasons 2007-2009, we estimated a total of 13955, 12028 and 19950 clutches in the 3 years, respectively. These values indicate that the mean number of nesting females averaged 3700. Considering that a female breed, on average, every 2.4 years, we estimate that the overall number of adult females in the population during these three seasons was 8900. These levels are much higher than those suggested in previous studies which were more constrained in spatial coverage. Our findings indicate that Cape Verde hosts the third largest nesting aggregation for this species in the world after the south-eastern US and Oman, with some sites having a particularly high density of nests, facilitating targeted monitoring and conservation. Consumption of sea turtle meat is a traditional practice in Cape Verde that continues despite national sea turtle protection laws. We estimated that 36, 18 and 5% of nesting females were harvested in the 3 years of the study, respectively. Increasing beach protection and monitoring, ongoing educational programs and cooperative projects with local communities are urgently needed to further safeguard the only major loggerhead nesting aggregation in the eastern Atlantic. © 2012 the Zoological Society of London.