DISTRICT LINE
Micro Waves Bridget Reed Morawski
Local scientists and researchers are trying to figure out how microplastics are impacting the Potomac and Anacostia watersheds.
One of the discs Jesse Meiller and J. Adam Frederick retrieved at National Harbor By Bridget Reed Morawski It was a gloomy Tuesday at National Harbor, with enough rainfall to soak your socks and render your eyeglasses useless. Save for a few rollicking ducks, few bothered to venture to the water’s edge on such a dreary day. Except for Jesse Meiller and J. Adam Frederick, that is. They crouched over a dock at the casino and convention hub, marveling at the marine life that had accumulated on aluminum discs they had submerged into this notch of the Potomac River. In the two weeks since the researchers last examined the discs and sunk them into the waterway, a miniscule menagerie of puffy sponges and gelatinous, mossy creatures known as bryozoans had formed. But while biodiversity is an essential component of their project, the work that Meiller and Frederick are conducting with the discs has evolved since it began: Now, they also want to investigate the presence of microplastics that may stick to the organisms. Mei l le r a n d F r e de r i c k , w h o wo r k
respectively for American University and Maryland Sea Grant, are among the small cadre of local researchers, educators, and advocates seeking to further the area’s collective knowledge about just how pervasive microplastics are in D.C.'s waterways. As the name implies, microplastics are tiny bits of plastic either intentionally created that way or bits of larger plastic products that have broken apart. The mere existence of microplastics in D.C.’s waterways is no singular circumstance. Microplastics have been found in waterways across the country, from shellfish on an Alaskan island to 10,000 feet above sea level in Colorado’s Rocky Mountain National Park. Closer to home, microplastics have been found in more than 50 Pennsylvanian waterways. However, urban areas like D.C. tend to have higher concentrations of microplastics in their watersheds than the waterways of less p o pu lated a rea s , accord i n g to Mat t Robinson, an environmental protection specialist with the District’s Department of Energy & Environment. But even though microplastics have been
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found in waterways and other ecosystems around the country, they’re an understudied topic and it’s currently unclear just how many have accumulated in the Anacostia and Potomac rivers. D.C. doesn’t have a continuous monitoring program in place for microplastics, says Robinson. “The one thing we have been doing for the past 10 years is we’ve been monitoring the macroplastics [and] the trash in the Anacostia and Potomac [rivers] and Rock Creek,” Robinson says. Because the Anacostia River is one of the most polluted rivers in the country, the federal government has put the city on a “pollution diet” known as a total maximum daily load. Complying with the TMDL essentially means that a jurisdiction must make sure a waterway identified as needing help meeting water quality standards cannot exceed a predetermined amount of pollutants. To adhere to the TMDL and minimize the amount of plastics that end up in its waterways, Robinson says the District has installed trash traps along the Anacostia, in addition to street sweeping programs, illegal dumping
enforcement, and litter clean-ups. But much of the trash in the waterways isn’t necessarily coming from the District, he says, particularly since the city instated the plastic bag fee in 2010. “If we can highlight the ecological impacts, the human health impacts, and even the economic impacts from plastic pollution, specifically microplastic pollution, then we can potentially get other jurisdictions to do more, and help us with reducing plastic pollution in our waterways and waterways downstream,” he says. In D.C., “We’re heavily impacted by upstream sources of pollution, yet we’re less than 17 percent of the Anacostia watershed.” “One reason we’re pushing microplastics research now is that a lot of the TMDL implementation is inspired by aesthetic impacts from trash pollution: We don’t want to see our waterways full of trash,” he adds. “However, there’s been very, very little work done on the ecological impacts of plastic pollution,” especially microplastics, he says, characterizing already published research on our waterways as “very disturbing.” Still, certain educated assumptions can be made, since we have a sizable volume of visible trash and larger plastics in these waterways, and because microplastics are often shed from such litter, Meiller says. But scientists prefer concrete research over mere assumptions, which is why, to identify whether or not fish in different parts of the Potomac River’s food chain consume different amounts of microplastics, a team composed of consulting firm Tetra Tech and the University of Maryland researchers will begin dissecting around 200 fish—blue catfish, mummichogs, largemouth bass, and striped bass—from across the Potomac River’s food chain this week. The fish, euthanized before being wrapped in aluminum foil, were collected this past spring, summer, and fall and stored at a Baltimore area lab, in a walk-in cooler large enough for Tetra Tech fisheries ecologist Bob Murphy to lay down in. (Not that Murphy has—it’s much too cold, he says, joking). The dissection project was created after Robinson and Murphy gave presentations at a 2019 workshop that highlighted that “we still have little idea of the magnitude and distribution of microplastics within the watershed, much less the potential impact microplastic pollution may be having on living resources,” according to a report summarizing the workshop’s findings. The workshop was convened by a committee that advises the Chesapeake Bay Program, a partnership of regional governments that have made various agreements to reduce sources of pollution in the watershed and revitalize the ecosystem. One of the recommendations that came out of that workshop was to “collaborate on utilizing the existing bay and watershed monitoring networks to monitor for microplastic pollution,” which led to federal and regional funding of the dissection project and other related projects. These projects aren’t the only local efforts,
