Can oysters filter nitrogen from local waterways? Boston University scientists will head to Stony Brook Harbor to find out

Scientists from Boston University will study the waters of Stony Brook Harbor to test oysters’ ability to filter nitrogen from local waterways in three Northeastern states.

Boston University visiting fellow Andrew Bouchie and Robinson W. Fulweiler, a professor with Boston University’s Departments of Earth & Environment and Biology, will lead the team. The study will run from April until October. Earlier this month, the Smithtown Town Board voted 5-0 to give researchers access to Long Beach Town Park in St. James for the purposes of the study.

Researchers will use a specialized solar-powered van that was converted into a mobile laboratory known as PEARL, short for the Public Engagement and Aquatic Research Laboratory. Team members will use the van to monitor and measure water quality samples at nine sites on Long Island, New Hampshire and Massachusetts to determine how capable oysters are in removing nitrogen from bodies of water, Fulweiler said.

By illustrating the oysters’ role in reducing nitrogen from local waters, the study could play a key role in spotlighting the need to fund oyster restoration efforts as well as aquaculture and aquafarming.

“Once nitrogen gets into the ecosystem, we’re really limited in how we can clean up the water … but oysters are an option,” Fulweiler said in an interview. “It’s about figuring out a way to protect our coastal waters, and we need every tool we can get.”

Fulweiler said oysters can filter water and remove particulates, which contain microscopic solids or liquid droplets. The oyster population has declined sharply on Long Island over the years, according to marine life experts. Across the globe, 85% of oyster habitats have disappeared, according to the National Institutes of Health. Several factors are behind that drop, including overharvesting of oysters, worsening water quality levels, disease and the spread of urban development along coastlines, the NIH said.

Nitrogen in local waterways on Long Island has been a long running issue, particularly in Suffolk County. Many homes in Suffolk use cesspools and are not connected to sewers. Nitrogen from cesspool waste can seep into the groundwater and flow into larger bodies of water, sometimes leading to algal blooms that are harmful to marine life, experts have said.

Chris Gobler, a professor at Stony Brook University’s School of Marine and Atmospheric Sciences, has been leading a research team into oyster populations at Stony Brook Harbor for several years. 

“Too much nitrogen can be a problem, particularly during the summer months,” Gobler said in an interview. “It can lead to harmful algal blooms, which can be damaging in some cases to ecosystems and marine life; and in other cases, they can create toxins harmful to animals and humans.”

Matthew J. Swain, vice president of Southampton-based environmental nonprofit Peconic Land Trust, said island-wide, nitrogen is the “most significant pollutant” in local waterways. Contributing factors include septic systems and fertilizer runoff, he said. The nonprofit has been coordinating with several partners to study nitrogen and other contaminants and conducting research on mitigation measures at Sagg Pond in Bridgehampton and Georgica Pond in East Hampton.

“There’s been a lot of efforts from local governments and environmental groups to reduce nitrogen pollution, and that’s been through initiatives like septic system upgrades, wetland restoration projects and permeable reactive barriers, for example, on the East End in certain areas,” Swain said.

Fulweiler said the team would like to eventually expand the study across the Eastern Seaboard. Widening the scope of the work would give the team “a more holistic picture” of how oysters can remove nitrogen from waterways, Fulweiler said.