How much plastic is ending up in shellfish?

It’s becoming an increasingly well- known fact that our oceans contain a considerable amount of plastic. So much so that scientists have warned that if we keep going at predicted rates of use, the stuff will outweigh fish in the world’s oceans by 2050. But just how much plastic is ending up in the seafood we eat, and what is the source?

New research by Vancouver Island University’s Sarah Dudas is helping provide answers, NPR reports. In 2016, she and a team of students analyzed thousands of clams and oysters they collected in the Strait of Georgia.

When you eat clams or oysters, you’re consuming plastic as well, the shellfish biologist says. “We’re finding most shellfish have plastic in them,” Dudas told NPR, adding her findings don’t show a difference between farmed versus wild shellfish.

Dudas’ study was funded by B. C.’s shellfish industry and Ottawa. NPR reports the driver was to determine the source of the plastics, and to find out whether or not fish farms were responsible. “Shellfish aquaculture uses a lot of plastic infrastructure,” Dudas said, such as nets and ropes that flake fibres.

So far, her data, as well as that of the Vancouver Aquarium’s Ocean Pollution Research Program, hasn’t identified a precise source. But they suspect many of the synthetic fibres end up in the ocean thanks to clothing; when washed, microfibres shed and slip through the filters in washing machines and water treatment plants into the water supply.

How worried should shellfish lovers be? Dudas’ preliminary results point to an average of eight microplastic particles in each clam or oyster, NPR reports. “I wouldn’t be overly concerned about eating shellfish specifically,” Dudas told NPR. “Microplastics are everywhere.”