Portland State University-led researchers have discovered significant levels of microplastics in six popular Oregon seafood species. The study sheds light on the presence of these harmful particles in the food chain and the urgency of developing technologies to curb plastic pollution.
Tiny plastic particles from clothing, packaging and other products are making their way into the fish that people eat, according to a new study led by Elise Granek, a professor of environmental science and management at Portland State University. This discovery sheds light on the prevalence of microplastic contamination in widely consumed finfish and crustaceans, emphasizing an urgent need for solutions to reduce environmental plastic pollution.
The research team from PSU’s Applied Coastal Ecology Lab focused on commonly eaten seafood species in Oregon.
Summer Traylor, who graduated with a master’s degree in environmental management in 2022 from PSU, spearheaded the project. She was assisted by undergraduate environmental science student Marilyn Duncan who graduated in 2024.
The researchers set out to fill gaps in existing data on microplastic contamination in Oregon’s seafood. They analyzed the edible tissue of six economically or culturally significant species: black rockfish, lingcod, Chinook salmon, Pacific herring, Pacific lamprey and pink shrimp.
The team compared particle concentrations across different trophic levels — which classify an organism’s position in the food chain — and examined contamination variations between samples obtained from research fishing vessels and those from supermarkets and seafood vendors.
In total, the study found 1,806 suspected plastic particles across 180 of 182 individual samples. The most prevalent types of particles were fibers, followed by fragments and films. Pink shrimp, which feed near the water surface, exhibited the highest concentrations of these particles, while Chinook salmon showed the lowest.
“We found that the smaller organisms that we sampled seem to be ingesting more anthropogenic, non-nutritious particles,” Granek said in a news release.
She noted that creatures like shrimp and small fish consume zooplankton, which often gather in areas with high plastic concentrations. These particles may closely resemble zooplankton, leading to their accidental ingestion.
The research, published in the journal Frontiers in Toxicology, also provided an important observation regarding the potential additional contamination from plastic packaging throughout the supply chain.
The researchers discovered that the processing from catch to consumer did not universally introduce extra contaminants, suggesting that rinsing seafood as typically done in home kitchens can mitigate some contamination.
The study’s findings highlight the widespread presence of plastic particles in the edible tissues of marine and freshwater species in Oregon.
“It’s very concerning that microfibers appear to move from the gut into other tissues such as muscle,” added co-author Susanne Brander, an ecotoxicologist and associate professor at Oregon State University. “This has wide implications for other organisms, potentially including humans too.”
Traylor, who is now a NOAA Corps Officer, emphasized the significance of the findings.
“This project established critical baseline data for West Coast fisheries stakeholders and highlighted how much we still do not know about these pervasive microplastic pollutants,” she said in the news release.
The study indicates that microplastics are pervasive across various food sources, not just seafood. Granek maintains that avoiding seafood isn’t a solution since microplastics are found in numerous other consumable products.
“If we are disposing of and utilizing products that release microplastics, those microplastics make their way into the environment and are taken up by things we eat,” Granek added.
Granek’s lab is now focusing on solutions to mitigate this pollution. Granek is leading a $1.9 million NOAA-funded project aimed at developing and testing cost-effective filtration solutions for washing machines, dishwashers and clothes dryers.
Additionally, Granek is part of an Oregon Sea Grant project installing catch basin filters in coastal towns to trap microplastics from road runoff before they enter waterways.
The continued research and development of such technologies are crucial steps toward controlling the spread of microplastics in the environment and ensuring safer food sources in the future.