Marine microplastics have a detrimental impact on the reproduction and health of invertebrates, such as oysters, worms and copepods. Image courtesy of Ceri Lewis.

Marine microplastics: Not just a drop in the ocean

The University of Exeter’s Professor Tamara Galloway and Dr Ceri Lewis have published a new commentary in the journal PNAS this week, highlighting the importance of a recent study on microplastics and their impact on the survival and reproduction of marine invertebrates.

Microplastics are small plastic particles (less than 1 mm) which have become ubiquitous marine contaminants, found from deep ocean sediments to the polar icecaps. Yet awareness of the biological damage of microplastics is still in its infancy, says Tamara Galloway, an ecotoxicologist at Exeter’s Streatham campus.

New research, carried out by scientists at France's national marine research agency (Ifremer) in Plouzané, found that polystyrene microparticles when consumed by Pacific oysters reduced the health and number of offspring they produced (Sussarellu et al., 2016). Lewis and Galloway’s research focuses on the impact environmental contaminants have on marine invertebrates, and they have emphasized how these results support an emerging paradigm that microplastics can reduce reproductive output and fitness in marine species.

Ceri Lewis says that the French study is "extremely important" as exposure not only reduced fecundity and sperm swimming speeds in the oysters but there was a clear carry over effect to the next generation with a reduced growth in the larval offspring observed for the first time. "This just adds to the long list of other stressors that are negatively impacting marine invertebrate’s ability to reproduce, such as climate change and ocean acidification", she says.

In their commentary, Lewis and Galloway also point out that a disturbance to a keystone species such as the oysters, which are of high ecological and economic importance, is of major concern. This oyster study has reinforced the need to act on the problem of marine litter. Galloway says that “anthropogenic litter is something we can do something about quite quickly if we want to by using less plastic and being more careful about waste disposal”.

Marine microplastics spell big problems for future generations by Tamara Galloway and Ceri Lewis.

Article written by Aoife Parsons, Biosciences Press Gang.

Date: 23 February 2016

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