Microplastics flushed into the oceans are causing mussels to lose their grip, a new study warned.

The tiny particles of plastic fragments are affecting the ability of mussels to attach themselves to their surroundings and triggering an immune response in the mollusc

The findings poses a threat to the survival of these mollusc which are an important part of the ecosystem and a billion pound industry.

Blue mussels were exposed to non-biodegradable microplastics less than five millimeters over 52 days.

They produced significantly fewer byssal threads, which are thin fibres that help mussels attach themselves to rocks and ropes.

As well as enabling mussels to clinch on when battered by waves and strong tides, these byssal threads also enable them to form extensive reefs that provide important habitats for other marine animals and plants.

The research carried out at the Portaferry Marine Laboratory in Northern Ireland

It also found the overall tenacity or attachment strength of the mussels, calculated by measuring the maximal vertical force required for the mussel to become dislodged from its position, fell by 50 per cent.

Researchers also measured the proteins within the mussel’s circulatory fluid or haemolymph, which performs a similar function to blood, to see what effect the microplastics had on the health of the mussels.

Worringly they found microplastics induced a strong immune response and also affected the mussels’ metabolism.

Dr Dannielle Green, a Senior Lecturer in Biology at Anglia Ruskin University in Cambridge said: “Tenacity is vital for mussels to form and maintain reefs without being dislodged by hydrodynamic forces.

“Our study showed that the presence of non-biodegradable microplastics reduced the number of byssal threads produced by the mussels, which likely accounts for the 50 per cent reduction in their attachment strength.

“Byssal threads help mussels to form aggregations, increasing fertilisation success and making mussels more resistant to predation.

“A reduction in these byssal threads in the wild could lead to cascading impacts on biodiversity as well as reducing yields from aquaculture, as mussels are more likely to be washed away by waves or strong tides.

“Our research also shows that even biodegradable microplastics can affect the health of mussels.

“Both biodegradable and non-biodegradable plastic are used in making single-use packaging, which if it becomes litter can break down into microplastics.

“Better recycling and an overall reduction of these materials can play an important role in helping to safeguard our marine environment.”

The research carried out at the Portaferry Marine Laboratory in Northern Ireland was published in the journal Environmental Pollution.

By Tony Whitfield