Ingesting prey that is contaminated with microplastics can affect the normal growth of fish larvae, according to research published in Limnology & Oceanography Letters yesterday (January 7).
Microplastics are plastic particles that are under 5mm in size. They are of increasing concern to researchers as more and more evidence is showing that they are frequently ingested by marine organisms.
For the experiment, microplastics were fed directly to the larval fish and then the fish were fed prey that had been fed microplastics. This allowed the researchers to investigate the effects of ingesting microplastics directly and the effects of ingesting microplastic-contaminated prey, a process called trophic transfer.
The researchers found that by consuming prey that contains the non-nutritious microplastics, the growth of the larvae was significantly reduced, they hypothesised that is possibly due to obstruction of the gut.
The researchers have said that reduced growth during the early life of the larvae could increase the amount of time that the fish spend in the larval stage which as a result could prolong the period that they are at risk of attack from other species and could alter the whole food web.
Lead author of the study, Samantha Athey, from the University of Toronto, said: ‘Our findings indicate that trophic transfer may be an important route for microplastic exposure in estuarine food webs and that even short exposure to high levels of microplastics can impair growth of an important prey fish.
‘Because estuaries are incredibly productive habitats that are home to many of our commercial seafood species in the United States, it is important to understand the sources, fate and effects of microplastics and associated pollutants in these systems.’
The researchers concluded that better understanding the impacts that microplastics have on food webs will be important for evaluating sources of marine pollution, establishing policies to mitigate litter and determining the human health risk of microplastics.
In related news, 2,700 water samples collected from the four European sea fronts and the nine major rivers in Europe shows that 100% of the water sources contain microplastics.
Researchers from the Tara Ocean Foundation embarked on a 6-month voyage around Europes water-ways bringing back 2,700 water samples from 45 sites.
The researchers have concluded that the microplastics represent more than 90% of the 5,000 billion pieces of plastic floating on the surface of our oceans.
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