MICROPLASTIC TOXINS LEAVE SHELLFISH AT MERCY OF PREDATORS
Research has found. microplastic toxins leave shellfish at mercy of predators. The chemical cocktail suppresses periwinkles’ ability to avoid crabs that eat them and disrupts the food chain. According to an article in The Guardian.
The world’s rivers and oceans are full of microplastics, which absorb poisonous chemicals from the water. Previouly it has been shown that mussels are harmed by these toxins when they eat microplastics, however the latest study is the first to show that this disrupts the relationship between predator and prey, which researchers say, could potentially disrupt the whole food chain.
It is known that microplastics are present in seafood, as well as tap water, salt and honey and probably numerous other foods. Humans are known to consume microplastics but the future impact on health is still unknown.
The research, published in the journal Biology Letters, looked at the common periwinkle, which grazes on algae but is eaten by crabs. It plays a central role in the food chain making it a keystone species on beaches. It is also widely eaten by people.
When a crab preys on a periwinkle, chemical cues normally induce the shellfish to take evasive action, such as hiding under rocks or withdrawing into their shells. But, in the lab, where the periwinkles were kept in water with microplastics collected from a beach near Calais in France, they failed to react.
“The whole set of behaviours are totally inhibited,” said Prof Laurent Seuront, at the National Centre for Scientific Research in northern France. “It is worrying news. If the periwinkles are not able to sense and escape from the predator, they are more likely to disappear and then to disturb the whole food chain.”
The microplastic cocentration used in the experiments was similar to that on the beach. Microplastics attract heavy metals and persistent organic pollutants and the researchers believe the release of this chemical cocktail interferes with the periwinkle’s senses. A previous study showed that toxins leached from microplastics led mussel larvae to grow in an abnormal way.
“Saturating our marine environment with microplastics is an enormous gamble,” said Paul Morozzo, of Greenpeace. “We are still only learning what the impact on individual species, like the periwinkle, or indeed us, might be.
“The odds are not good, and we’re dumping an extra truckload of risk into the sea every 60 seconds,” he said. “The best way to reduce the danger is to reduce our use of plastic, quickly and dramatically. That includes a ban on problem and unrecyclable plastic by 2019.”