Turtles have been dying in significant numbers near some of the creeks leading into Peconic Bay, amounting to an “unprecedented” die-off, according to environmental advocates and state conservation authorities.
The likely culprit? A marine biotoxin caused by a red tide algae bloom, according to the findings of a state pathology lab investigating the die-off. With fish also reportedly dying by the thousands, the state and county have closed several East End creeks and bays after finding evidence of the toxins.
On Saturday, Flanders Bay and western Shinnecock Bay were added to the list of local water bodies where the harvesting of shellfish is temporarily prohibited, the New York Department of Environmental Conservation announced.
Three North Fork creeks — Meetinghouse and Terry creeks in Aquebogue and James Creek in Mattituck — were also shut down by the state in the last two weeks.
The notice bans fishermen from harvesting shellfish or carnivorous gastropods — like whelks, conchs and moon snails — from the creeks and bays.
According to the DEC, elevated levels of saxitoxin were found in mussel samples. Saxitoxin can be harmful to humans and animals if consumed, according to the DEC.
Contact with water in and around the areas currently closed to shellfishing isn’t expected to cause any problems, DEC officials said, but residents are urged to avoid water that appears discolored. If contact does occur, the water should immediately be rinsed off with clean water, they said.
According to the DEC, symptoms of saxitoxin poisoning depend on the amount ingested and can progress “from tingling of the lips and tongue, to numbness of the face, neck and limbs, loss of muscular control, followed by difficulty breathing,” according to a press release. Officials said full quantitative results from affected water bodies will be available later this week.
Saxitoxin is produced by the algae responsible for red and brown tides.
“It’s a microscopic organism that grows in the water and this is the time of year we usually see it,” said Christopher Gobler, associate dean of research at Stony Brook University’s School of Marine and Atmospheric Sciences. Mr. Gobler’s team handled the May 15 research that led to the closure of Flanders and Shinnecock bays.
“It’s most common in areas that have high levels of nitrogen in the water and slow flushing rates,” he said.
In addition to the latest closures, the DEC said it has discovered many dead diamondback terrapin turtles throughout Flanders Bay that are thought to have died after eating contaminated mollusks.
Mr. Gobler said Stony Brook University students counted at least 50 dead turtles alone at Iron Point Park in Flanders on Friday. Other groups, including Turtle Rescue of the Hamptons, reported that dozens more dead turtles have been recovered since late April. Figures for exactly how many weren’t immediately available.
Mr. Gobler said several thousand bunker and bluefish in the Peconic River also died recently, possibly due to low oxygen levels.
“It’s disconcerting,” he said. “In one week we have toxic shellfish, dying turtles and dying fish, all in the same general region.”
Mr. Gobler said he can’t recall a time when so many turtles were found dead.
“I’ve never heard of anything like this,” he said.
Although findings from turtle necropsies were “nonspecific” — meaning their deaths could not be directly tied to the presence of saxitoxin — testing on the contents of the animals’ intestines, while inconclusive, did reveal that saxitoxin may have been present, according to the DEC.
“Circumstantial evidence is consistent with the terrapins being poisoned with saxitoxin,” said state spokesperson Lori Severino. “If additional terrapin carcasses are found, [the] DEC will test them as well in an effort to confirm the cause of deaths in this terrapin die-off.”
Turtle Rescue of the Hamptons Executive Director Karen Testa said the group had been finding dead diamondback terrapin turtles — an aquatic species that prefers the brackish waters of creeks and small bays — as far north as Cutchogue.
Ms. Testa called the species the “puppy dog” of turtles, noting their personalities and how they will beg for food like a domesticated animal.
The turtles they’ve found have shown no signs of trauma.
“This has never, ever happened around here,” she said.