2025 was a bad year for Long Island’s coastal waters, largely due to wastewater and fertilizer runoff, but the poor conditions bring opportunities for innovative water quality improvement techniques — like using mollusks and seaweed to clean up contamination.
Research from Stony Brook University’s Christopher Gobler shows Long Island waterways suffered fishkills, harmful algal blooms, low-oxygen dead zones, and even flesh-eating bacteria, mostly due to nitrogen pollution.
“[There are] dozens and dozens of locations in our estuaries and our harbors and our bays and our lakes and our ponds where the water quality is not meeting state and federal standards,” Gobler said at a news conference on Tuesday ahead of his annual “State of the Bays” Symposium last Friday.
Despite the poor water quality report, Gobler said he’s hopeful that new developments in remediation technologies can remove contaminants from both surface and drinking water.
“We're innovating on a series of new septic systems,” Gobler said. Our first round is called the nitrogen-removing bio filter, and in exciting news, they're performing just as well as any of the commercial I/A [Innovative & Alternative wastewater treatment] systems. Beyond removing nitrogen, they're also removing all sorts of contaminants we don't want in our drinking water: drugs, pharmaceuticals, personal care products.”
Removing nitrogen from Long Island’s bays and lakes is the key to reducing harmful algal blooms and other maladies. Another way to remove pollution is to use bivalves, since their biology means they act as filters, and even seaweed.
“Seaweed and shellfish are absolutely zero input crops,” said Michael Doall, associate director for bivalve restoration at the Stony Brook University School of Marine and Atmospheric Sciences. That means they don’t require fresh water, feed, fertilizer or pesticide to thrive.
“So instead of feeding them, they get their nutrition from the waters around them, and in so doing, they're taking nitrogen out of the water,” Doall said.
Putting seaweed and bivalves to work remediating surface water has more than just an environmental benefit, according to Doall. It also creates jobs for coastal economies.
“Shellfish and seaweed aquaculture is a real win for Suffolk County and for all of Long Island,” he said.
