Microplastics found in oysters, clams on Oregon coast, PSU study finds

November 12, 2019

Tiny threads of plastics are showing up in Pacific oysters and razor clams along the Oregon coast -- and the yoga pants, fleece jackets, and sweat-wicking clothing that Pacific Northwesterners love to wear are a source of that pollution, according to a new Portland State University study.

Britta Baechler, a Ph.D. student in PSU's Earth, Environment and Society program, and Elise Granek, a professor of environmental science and management, looked at what variables predict microplastic concentrations in Pacific oysters and razor clams -- organisms that have commercial, recreational and cultural importance in Oregon.

On average, the researchers found 11 microplastic pieces per oyster and nine per clam in the samples, and nearly all were microfibers, which can come from clothing made from synthetic or natural materials as well as derelict fishing gear.

"These microfilaments can be shed from clothing, up to 700,000 per load of laundry," Baechler said. "Those particles then travel out through greywater into wastewater and to the coast."

Microplastics were found in both Pacific oysters and razor clams collected from all 15 sample sites along the Oregon coast during spring and summer 2017. Microplastics were found in all but two of the roughly 300 organisms sampled.

The team also found that spring oysters contained more microplastics than the oysters sampled from the summer. Baechler said seasonal precipitation and the type of clothing typically worn in the spring compared to summer may have been factors.

"Whether it was a fairly urban site or a rural site, estuary or open-coast beach, both species had microplastics," Granek said. "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 microplastics, we're still seeing that human footprint on even our more pristine coastline."

Granek said that because fishing gear can be a source of microfibers, fisheries and oyster growers are often blamed for the problem of microplastics in seafood -- but there is no scientific consensus that this is the case.

"It's not because people aren't managing our fisheries well or are being unclean in their practices," she said. "We're all using plastics on a daily basis. We are all the source of contamination in our seafood. And microplastics are not just in our seafood. We know that they are in our beer, in our salt, in our drinking water."

Baechler and Granek said more research still needs to be done to determine what effect the microplastics have on the organisms themselves and the humans who consume them. Studies have shown that microplastics can have negative physiological impacts such as reproductive and growth impairments on oysters and clams.

"If reproduction or growth is impaired, that could really affect not just individual clams or oysters, but possibly local populations of these organisms as well," Baechler said.

Granek said engineers are coming up with filters that could attach to washing machines, but it's still too early to tell how effective they are at preventing microfibers from discharging into the water and whether they're too costly for the general public.
-end-
The team's research was supported by Oregon Sea Grant, and their findings were published in the journal Limnology and Oceanography Letters. The team also included Matthew Hunter from the Oregon Department of Fish and Wildlife and Kathleen Conn from the U.S. Geological Survey.

Portland State University

Related Plastics Articles from Brightsurf:

Bioplastics no safer than other plastics
Bioplastics contain substances that are as toxic as those in ordinary plastics.

A first-of-its-kind catalyst mimics natural processes to break down plastics
A team of scientists led by the U.S. Department of Energy's Ames Laboratory has developed a first-of-its-kind catalyst that is able to process polyolefin plastics, types of polymers widely used in things like plastic grocery bags, milk jugs, shampoo bottles, toys, and food containers.

Plastics, waste and recycling: It's not just a packaging problem
Discussions of the growing plastic waste problem often focus on reducing the volume of single-use plastic packaging items such as bags, bottles, tubs and films.

'Critical' questions over disease risks from ocean plastics
Key knowledge gaps exist in our understanding of how ocean microplastics transport bacteria and viruses -- and whether this affects the health of humans and animals, researchers say.

Plastics, pathogens and baby formula: What's in your shellfish?
The first landmark study using next-generation technology to comprehensively examine contaminants in oysters in Myanmar reveals alarming findings: the widespread presence of human bacterial pathogens and human-derived microdebris materials, including plastics, kerosene, paint, talc and milk supplement powders.

Chemists make tough plastics recyclable
MIT chemists have developed a way to modify thermoset plastics with a chemical linker that makes it much easier to recycle them, but still allows them to retain their mechanical strength.

The many lifetimes of plastics
Many of us have seen informational posters at parks or aquariums specifying how long plastics bags, bottles, and other products last in the environment.

Recycling plastics together, simple and fast
Scientists successfully blended different types of plastics to be recycled together, providing a solution to the environmental problem of plastic waste and adding economic value to plastic materials.

Water replaces toxins: Green production of plastics
A new way to synthesize polymers, called hydrothermal synthesis, can be used to produce important high-performance materials in a way which is much better for the environment.

Untwisting plastics for charging internet-of-things devices
Scientists are unraveling the properties of electricity-conducting plastics so they can be used in future energy-harvesting devices.

Read More: Plastics News and Plastics Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.