A Bad Year for Algae Blooms has Scientists Wondering: “Where’s The Tipping Point?”

Pictured Above: The Gobler Laboratory and The Nature Conservancy’s overview of trouble spots in Long Island waters last year.

Toxic algal blooms were widespread on Long Island in 2023, and strains of algae and bacteria not seen before here began to make headway in local waters, according to Stony Brook ecologist Dr. Christopher Gobler, who gave his annual State of the Bays address at Stony Brook Southampton April 3.

Researchers had reported earlier in 2023 in the journal “Nature” that they thought this “flesh-eating bacteria” would reach Long Island for five years, as it moved up the warming waters of the East Coast.

“That paper held true for about five months,” said Dr. Gobler, who reported the bacteria was found in two clusters in water bodies studied by his laboratory — on the North Shore and in East Hampton.

“It’s directly a function of more rainfall and water temperatures,” said Dr. Gobler, who pointed out that the bacteria thrives in marine areas that receive a lot of freshwater runoff. 

The waters around Long Island have been warming at three times the global average since 2002, he said, adding that the average rainfall here should be about four inches a month, but “in some extreme single-day events, we’re getting a month of rain all at once.”

“In the summer, if it’s warm and you have an open cut, you shouldn’t go in the water,” is Dr. Gobler’s advice for avoiding Vibrio, which killed three people who came in contact with infected waters in New York and Connecticut last year. “ If you get a cut in seawater, clean it out. It infects open wounds. It can accumulate in shellfish, but oysters for sale in New York are always iced,” which prevents the bacteria from growing.

“No one has died from Vibrio in shellfish in New York,” he added.

Dr. Gobler’s lab conducts weekly water monitoring at locations all over Long Island during the summer, and this year, for the first time, a researcher there found the algae Pseudo-nitzschia, a distinctive skinny, pencil-like diatom that can produce the neurotoxin domoic acid, which can cause a disorder known as amnesic shellfish poisoning, across much of Great South Bay, in all of Moriches Bay, and in western Shinnecock Bay.

He said this algae, more commonly found on the West Coast, is best known as the driver behind the deaths of birds in the Alfred Hitchcock film “The Birds,” and for a 1987 outbreak among humans who had eaten mussels grown in the bays of Prince Edward Island, Canada.

“We had been missing this, and we went back and found it in prior years,” said Dr. Gobler. “Are the levels dangerous, and what triggers these harmful algal blooms? We don’t know yet how it fits into the scheme of things… It was unknown to the East Coast until within the last decade.”

The news from established harmful algae blooms, which have been proven to be fed by the nitrogen in Suffolk County’s hundreds of thousands of aging on-site septic systems, wasn’t pretty either.

Toxic blue-green algae, which is found in freshwater, was widespread in Suffolk County in 2023, with “about a dozen sites on the South Fork that came up last year all at once,” he said, including “the most intense algae bloom of the season” two days after Labor Day in Fort Pond Bay in Montauk.

And the “Red Tide” algae Alexandrium, which produces paralytic shellfish poisoning-causing saxitoxin, “was endemic to waters across Long Island” in the summer of 2023, according to Dr. Gobler, who added that there were shellfish bed closures in seven locations where there had never been shellfish closures before.

“In areas where we can’t monitor the entire coastline, it can be dangerous,” he said. “2023 had more of these events than any year prior.”

The “Rust Tide” algae Cochlodinium, which can kill fish, had the earliest start ever recorded by the lab when it began in Shinecock Bay in mid-July, spreading throughout all of the Peconic Estuary. It was also the longest lasting rust tide bloom since the lab began monitoring, ending in early October. 

One of the worst blooms of 2023 was of Dinophysis, which can be toxic to shellfish, in Little Seatuck Creek in Eastport, where Dr. Gobler said his researchers found a “density of bloom at 100 million cells per liter — the record before was 2 million.”

Dr. Gobler titled his lecture “Where is the Tipping Point?” but that is a question that he said he can’t answer.

“In science, sometimes there’s a point of no return, where something changes so much, you can’t get it back. Often times in science, we don’t know when we’ve reached or passed the tipping point,” he said. “I don’t have the answer. Sometimes, when these things happen, it can change pretty dramatically.”

Is there any good news out there on the bays?

Dr. Gobler reported that the Shinnecock Bay Restoration Program is still proving that humans can bring back an ecosystem by spreading seed clams and restoring eelgrass beds, and that “clammers are now making a living in summer in Shinnecock Bay.”

Pilot programs to grow kelp alongside existing oyster farms have also found that kelp removes a great deal of nitrogen from the bays.

“A one-acre kelp farm can remove 100 to 200 pounds of nitrogen per year, equal to upgrading septic systems on eight to 18 homes,” said Dr, Gobler, who added that kelp also helps neutralize acidity in the water, creating a better growing environment for the oysters.

Kelp is a winter crop, but Dr. Gobler said Michael Doall, the Associate Director for Shellfish Restoration and Aquaculture at Stony Brook’s School of Marine and Atmospheric Sciences (SoMAS), has been working to find summer species of seaweed that could fill the same role.

In addition to numerous commercially available nitrogen reducing septic systems, now required in all new construction in Suffolk County, the Stony Brook Center for Clean Water Technology received Provisional Use Approval in April of 2023 for its Nitrogen Reducing Biofilter, a “very simple technology — a drainfield underlined by sand and wood chops,” said Dr. Gobler. “It needs a little more space [than other systems], but it’s very effective in removing contaminants.”

Dr. Gobler said Stony Brook researchers have found NRBs reduce nitrogen better than commercially available systems, and also remove a host of other chemicals. Residents interested in installing an NRB can call Stony Brook’s Center for Clean Water Technology at 631.216.7417.

“We’re not going to solve climate change with kelp, but kelp, when co-grown with shellfish, can have positive effects on the shellfish,” he said. “But upgrading septic systems is the primary mitigation strategy.”

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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 beth@peconicbathtub.com

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