Microplastics are altering the behaviour of periwinkles making them easier prey, a new study has claimed.

The study, published in the journal Biology Letters, says the small shellfish – which play a crucial role in the ocean eco system and are also widely eaten by humans – are losing the ability to detect and hide from crabs.

The researchers experimented by keeping the crabs in water contaminated by microplastics collected from a beach in France.

They found that when microplastics were present, the periwinkles failed to react when crabs approached them. Usually they are able to detect crabs using chemical cues and take action to hide in their shell or underneath a rock. 

The scientists believe that microplastics can interfere with the creatures’ senses.

“The whole set of behaviours are totally inhibited,” Prof Laurent Seuront, from the National Centre for Scientific Research in France said.

“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.” 

In a separate study earlier this month, scientists found microfibres in the faeces of fur seals living on a remote Chilean island.

They found tiny plastic fragments – smaller than one millimetre, in the waste of the seals – who live on Guafo Island, which is uninhabited by humans and used as a seal breeding ground.