PORTLAND, Ore. — Pacific shellfish found off the coast of Oregon are an integral part of the state’s economy, not to mention its appeal to tourists and overall culture. Unfortunately, a new set of research performed at Portland State University finds that pollutants known as microplastics are being detected in oysters and razor clams along the Oregon coast.
Plastic pollution within the Earth’s oceans is being caused by a much larger problem regarding careless waste disposal. That being said, researchers claim that yoga pants, fleece jackets, and other sweat-absorbing clothes frequently worn by Pacific Northwesterners are significantly contributing to this local plastic problem.
The study’s authors found roughly 11 microplastic pieces in each collected oyster, and nine microplastics per clam. Nearly all of these plastics were microfibers, typically found in clothing made from both synthetic and natural materials, as well as fishing equipment that hasn’t been properly maintained.
“These microfilaments can be shed from clothing, up to 700,000 per load of laundry,” explains PSU Ph.D. student Britta Baechler, one of the study’s main authors, in a media release. “Those particles then travel out through greywater into wastewater and to the coast.”
Pacific oysters and clams were collected from 15 different locations along Oregon’s coast during the spring and summer of 2017. Of the roughly 300 mollusks collected, only two contained absolutely no plastic.
Researchers noted that oysters collected during spring months tended to contain more plastic than those picked up over the summer. Differences in seasonal precipitation, as well as different seasonal fashion choices, were listed by Baechler as possible reasons for this observation.
“Whether it was a fairly urban site or a rural site, estuary or open-coast beach, both species had micro-plastics,” explains study co-author Elise Granek, a professor of environmental science and management at PSU. “Although we think of the Oregon coast as a much more pristine coastline compared to California, Puget Sound or the Eastern Seaboard, when we are talking about micro-plastics, we’re still seeing that human footprint on even our more pristine coastline.”
While it is certainly true that fishing gear can produce microfibers, this study’s authors caution that there is no scientific consensus that fishing equipment is contributing to the problem of microfibers being found in seafood.
“We’re all using plastics on a daily basis. We are all the source of contamination in our seafood,” Granek elaborates. “And microplastics are not just in our seafood. We know that they are in our beer, in our salt, in our drinking water.”
More research is still needed to fully explore the impact micro-plastics are having on sea life, and the humans who end up consuming affected seafood. So far, studies have found that micro-plastics can cause reproductive and growth problems among oysters and clams.
According to Granek, engineers are already working on plastic filters for washing machines, but it is still too early to say how effective these devices may be at stopping microfibers from making their way into water supplies. Cost is another barrier, as the first wave of these filters may be too expensive for many Americans.
The study is published in the scientific journal Limnology and Oceanography Letters.