Cold Spring Harbor experienced “poor” water-quality conditions in June because of the presence of a harmful algae bloom that can cause gastrointestinal illness, but most of the water body remains open to shellfishing.
The recent discovery of the Dinophysis bloom in Cold Spring Harbor was first reported in the Long Island Water Quality Report by Stony Brook University’s Gobler Laboratory.
The bloom reached “unusually high levels and is creating poor conditions,” the lab reported.
The state Department of Environmental Conservation, which has authority over shellfish closures, said Monday it hasn’t yet conducted tests of shellfish in Cold Spring Harbor to determine whether the pathogen is present. But the agency said it would do so if water tests by the Gobler lab indicate an algae-bloom increase.
In an email in response to Newsday questions, the DEC noted that three areas of Cold Spring Harbor already are closed to shellfish harvesting, including two that are seasonally closed from May 1 through Oct. 31. A third, southernmost portion has been off limits to shellfishing for more than a decade. “No one should be eating any shellfish taken from that part of the harbor,” the DEC said.
A release on June 28 by the DEC announced the closures of three water bodies to shellfishing, but Cold Spring Harbor wasn’t included. Among the recent closures were 445 acres in a section of Oyster Bay Harbor.
The agency last week said it had not conducted tests of shellfish in Cold Spring Harbor because that southern section, where the water monitoring occurs “is not certified for shellfish harvest.”
As for the those parts of Cold Spring Harbor open to shellfishing, the agency said it “believes that there is sufficient buffer in the closed area, that does not warrant further action at this time.”
However, DEC said, “If SUNY Marine Sciences reports that the algae bloom numbers this week have increased, DEC will collect a shellfish sample for testing.”
Christopher Gobler, professor at Stony Brook University’s School of Marine and Atmospheric Sciences who heads up the water study, said it’s “not fully clear” if Dinophysis levels detected at Cold Spring Harbor would rise to the level of causing toxicity in humans.
But he noted cell densities found in the harbor “have previously led to the accumulation of diarrhetic shellfish poisoning toxins in shellfish on Long Island.”
Thus far, no anecdotal impacts have been reported to Gobler, who is also co-director of the New York State Center for Clean Water Technology at Stony Brook. Investigation and monitoring of the Cold Spring Harbor algae bloom are ongoing, he said.
Gobler on Friday reported the Cold Spring Harbor algal bloom associated with the Dinophysis finding have since subsided, but said, “Others have since popped up that are toxic to fish but not humans.”
Research suggests blooms tied to Dinophysis are becoming more common.
The Virginia Institute of Marine Science identifies Dinophysis as an “emerging bloom species” in the United States, most often associated with “diarrhetic shellfish poisoning.” Symptoms include diarrhea, nausea, vomiting and abdominal pain. The first U.S. outbreak in 2008 resulted in the closure of a Texas coastal shellfishery, the institute reported.
The DEC said blooms linked to Dinophysis are “not rare in waters closed to shellfishing due to elevated fecal coliform levels.” The agency said it was “not aware of any illnesses linked to Dinophysis” from the harbor.
Earlier this month, the DEC lifted a ban on the gastropod harvest in Northport and Huntington harbors, but the agency’s Temporary Shellfish Information Line still cites a closure for shellfish in those waters. The closures were the result of a separate, unrelated “harmful” bloom tied to saxitoxin. The Stony Brook testing lab last week classified water quality in Northport and Huntington harbors as “poor.”
Grace Kelly-McGovern, a spokeswoman for the Suffolk County Department of Health Services, deferred to the DEC on the issue of shellfish closures.
However, she said, “It is our understanding that the algal bloom in Cold Spring Harbor is currently in an area that has been closed to shellfishing for over a decade.”
She added, “Residents and visitors to Suffolk County should not eat shellfish harvested from areas that are closed to shellfishing.”