State of the Bays: Turning the Nitrogen Tide

Pictured Above: Dr. Christopher Gobler at his 2019 State of the Bays address.

One of Long Island’s bays has seen some signs of hope this year of a comeback from rampant algal blooms, said Stony Brook University Professor Christopher Gobler at his annual State of the Bays address April 5.

But there is still much more work to be done, he said, pointing out a steady stream of toxic blue-green algae blooms in freshwater bodies in Suffolk County.

Dr. Gobler gives his annual address each spring at Stony Brook Southampton, outlining the work being done in his lab and by environmental groups to monitor and work to improve the quality of our waters here.

April 3, 11:10 a.m., Shinnecock Bay from Montauk Highway
Shinnecock Bay from Montauk Highway

This past year, 2018, was the first in 12 years that there was not a brown tide in Shinnecock Bay — a “reversal of a decadal trend” that Dr. Gobler attributes to the success of the Shinnecock Bay Restoration Program (SHiRP), which has been working to reseed the bay with shellfish.

Dr. Gobler said a long-term problem facing Shinnecock Bay was the density of clams there, which had been less than one clam per square meter, making it difficult for spawning clams to be fertilized.

SHiRP, along with researchers from Stony Brook, whose marine station is on Shinnecock Bay, created ‘spawner sanctuaries’ throughout the bay, seeding the areas with clams at a density designed to encourage spawning in the wild.

“There was a great expansion of the population,” said Dr. Gobler, who added that the lab had drafted a chart of where they expected the offspring to end up due to the currents in the bay.

“That’s exactly where we’re seeing them show up,” he said. “Shinnecock bay is one-tenth the size of the Great South Bay, but at present there are about the same amount of hard clams being harvested out of both.”

Seeding a bay with clams reinforces the health of the bay — not only does it lead to more successful spawning, but the clams, which are filter feeders, also filter algae out of the water, making it easier for eelgrass beds to recover from harmful algae blooms, which block the sunlight from reaching the essential eelgrass habitat.

Dr. Gobler said researchers have seen a gain of almost 100 acres of seagrass in western Shinnecock Bay.

The largest contributor to harmful algae blooms in the East End’s bays has been found to be effluent from the roughly 360,000 individual septic systems in Suffolk County. Nitrogen from the urine in those septic septic systems has been fueling the growth of algae blooms for decades, and researchers are just beginning to find innovative ways to counteract this input.

Dr. Gobler serves as the director of the New York State Center for Clean Water Technology at Stony Brook, which has been working since 2015 to study new technology to filter nitrogen out of septic systems.

He said the center’s goal has been to get systems approved by the Suffolk County Department of Health Services that reduce nitrogen below 10 mg/L, cost less than $10,000 and last 30 years.

The center has had some success getting systems to reduce nitrogen below 10 mg/L, he said, but the cost part of the goal has been a challenge.

Dr. Gobler said the systems currently cost somewhere between $20,000 and $25,000 to install. Suffolk County is offering grants of up to $10,000 for the systems, as are each of the South Fork towns.

Currently the Center for Clean Water Technology is testing three systems known as “nitrogen reducing biofilters,” said Dr. Gobler, which use wood chips buried in a drain field to filter the water.

In the next phase, they are working on three more systems that “use existing infrastructure to get the costs even lower,” he said.

A blue-green algae bloom in Southampton's Lake Agawam in September of 2018.
A blue-green algae bloom in Southampton’s Lake Agawam in September of 2018.

On the blue-green algae front, Dr. Gobler said the statistics are not looking good.

“There are more blue-green algae blooms in Suffolk County than anywhere in the state,” said Dr. Gobler of the algae blooms, adding that Lake Agawam in Southampton has the worst blue-green algae blooms in the state, with Mill Pond in Water Mill taking third place.

“This is not surprising. It happens every year,” said Dr. Gobler.

Blue-green algae contains the neurotoxin microcystin, which Dr. Gobler said is not only toxic, but also carcinogenic, and “can be airborne and travel more than a mile from a water body.”

“It’s shown up deep in human lungs,” he said.

Dr. Gobler said his lab works closely with New York State to monitor blue-green algae blooms here and provide details to the public so that people avoid swimming or letting their kids or pets near the toxic water.

“Thankfully, we live in the state that’s the most progressive in the nation for monitoring blue-green algae,” he said. “It’s a serous health threat, and the state takes it very seriously.”

Beth Young

Beth Young built her first boat out of driftwood tied together with phragmites behind her family’s apartment above the old Mill Creek Inn in Southold. Nowadays, she spends most of her time kayaking, learning about shellfish, writing newspaper stories, trying to sail a Sunfish, and watching the way the bay changes from day to day. You can send her a message at

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