A study published by West Virginia University in the journal Sustainability found microplastics in every fish tested across seven freshwater streams in North Central Appalachia.
Undergraduate biology student Isabella Tuzzio found microplastics – pieces of plastic less than 5 millimeters – in 55 juvenile northern hogsucker fish in tributaries of the Cheat, Ohio and Monongahela Rivers. The study was conducted to fill a gap in knowledge on microplastics in freshwater ecosystems.
Tuzzio tested northern hogsuckers because they live near the bottom of the stream, making them particularly vulnerable to microplastic pollution. This is because microplastics sink to the bottom where this species feeds. On average, Tuzzio said there were 40 pieces of plastic per individual fish and 2,185 total microplastics.
In addition to sampling fish, Tuzzio and collaborators evaluated land cover and collected E. Coli, bacteria associated with sewage.
“We found the most plastics within the Cheat watershed, and then we linked that to agricultural land use patterns and E. Coli presence,” Tuzzio said. “I pointed to local drivers of human contribution to microplastic pollution in the area.”
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Microplastics can come from a variety of sources: the weathering of larger plastics, microbeads from beauty products, and from clothing.
“Like 98% of the plastics that we found were fibers,” Tuzzio said. “When you wash clothes, [fibers] come off your clothes, and then that goes right into our sewage and right back into our water.”
Tuzzio said other potential sources of contamination include agricultural activity, wastewater and atmospheric deposition, which is when weather like rain or wind move particles across the Earth’s surface.
A 2021 study identified a lack of research on microplastics in freshwater ecosystems compared to their marine environments. Tuzzio said there is also a lack of research in Appalachia specifically.
“This was really important in providing a baseline for the amount of plastics that are in our waterways locally and finding those mechanisms for where it was coming from,” Tuzzio said.
Brent Murry, an assistant professor of aquatic ecology and a contributor to the study, compared Tuzzio’s study to a previous study by a former WVU master’s student, which examined larger, adult fish in a larger river.
“We’re getting similar amounts of plastic in all of them, so it doesn’t seem like ecosystem size is a factor, but we just have so many unanswered questions,” Murry said. “This is really an … emerging pollutant, emerging problem. We’re just beginning to understand.”
Impacts of microplastic pollution
The spread of microplastics in freshwater systems has both ecological and human health implications, according to assistant professor of wildlife and fisheries Caroline Arantes, who also worked on the study. Microplastics can disrupt the food web in ecosystems.
She said microplastics have surfaces that can act as vectors for other pollutants and pathogens, like bacteria, that get attached to those surfaces.
“They can become toxic to aquatic organisms, so they can be ingested by organisms and potentially move up the food chain,” Arantes said.
One particular problem is bioaccumulation, where a smaller fish can have a lower concentration of microplastics, but that concentration increases higher up in the food chain.
For humans, ingesting microplastic is linked to health risks including certain cancers, respiratory disease and inflammatory bowel disease.
There is a compounding effect of those sources of degradation, which in addition to microplastic and other pollutants … can really put our freshwater ecosystems at risk.
In addition to microplastics, freshwater ecosystems face challenges like acid mine drainage, urbanization, climate change, overfishing and deforestation.
“There is a compounding effect of those sources of degradation, which in addition to microplastic and other pollutants … can really put our freshwater ecosystems at risk,” Arantes said.
What’s next?
According to Tuzzio, one thing people can do about microplastics is reduce plastic use and recycle.
“Recycling is going to be the biggest one that you can do at home, and then the basic plastic cleanup efforts that we see. If you see something pick it up, make sure that it’s not in the water,” Tuzzio said.
Murry said no single discipline can come up with a solution to microplastic pollution, and that it requires collaboration across sectors.
“This project started a collaboration between myself, Dr. Arantes – both aquatic ecologists – and then a professor from the fashion design department who was really interested in what types of fabrics shed more, and so … they’re developing new synthetics … to prevent the flaking off of fibers and so we’re trying to work with fashion design,” Murry said.
Following Tuzzio’s study, Murry said he and a group of recent college graduates will study freshwater springs across the state as part of the One Health West Virginia initiative. Another student is also working in the same streams as Tuzzio, looking at 10 species instead of just the northern hogsuckers.
“Isabella’s was the first study,” Murry said. “[It] provides a really awesome foundation, which now we can go in all kinds of different directions. It’s really exciting.”
