When blue mussels were exposed to non-biodegradable microplastics over 52 days, they lost half their power to stick to surfaces. (Credit: Alamy Stock Photo)
According to an article on Theguardian.com, mussels start to lose their grip when exposed to microplastics, research has found, in the latest example of the damaging effects of plastic pollution on marine life.
When blue mussels were exposed to doses of non-biodegradable microplastics over 52 days, they lost about half their power to stick to surfaces. The weakening of their attachment appears to be the result of producing many fewer byssal threads, the thin fibres produced by mussels that enable them to attach to rocks, ropes and other undersea environments.
The research, carried out at the Portaferry Marine Laboratory in Northern Ireland, and reported in the journal Environmental Pollution, is among the first to study the effects of microplastics on marine organisms.
Microplastics have been found across the world in a wide variety of environments, from tapwater and seawater to flying insects and are probably even in the air we breathe. Last year, a study found microplastics in human faeces for the first time.
Some are microplastics that have been deliberately manufactured, for instance as microbeads in cosmetics, but most are the result of the breakdown of bigger pieces of plastic debris. There are vast numbers of sources of microplastics – for instance, synthetic clothing can shed tiny fibres when washed – making it difficult to remove them from use.
If mussels are losing their grip in the wild as well as under study conditions, the effects will be felt beyond the mollusc population. Mussels cling together and form reefs, which help them to breed, and shelter myriad other marine animals and plants, playing an important role in the marine ecosystem.
Dannielle Green, senior lecturer in biology at Anglia Ruskin University, who led the research, said: “Tenacity is vital for mussels to form and maintain reefs without being dislodged by hydrodynamic forces. A reduction in 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.”
Microplastics also appear to induce a strong immune response in mussels, and affect their metabolism, the researchers found. They measured the vertical force needed to dislodge a mussel from its attached position, and found that in those exposed to non-biodegradable microplastics over a period of 52 days, the force required was only half that required in a control sample without such exposure. There were also effects from exposure to biodegradable plastics, but these were less marked.
