Two Southold creeks close shellfish harvesting due to biotoxin

Shellfish harvesting is temporarily closed in Town and Jockey Creeks in the town of Southold effective April 16. This is due to the detection of saxitoxin, a marine biotoxin that causes paralytic shellfish poisoning (PSP), in mussels from the creeks. 

While uncommon, these closures are not unheard of this time of year. 

“When water temperatures warm, marine biotoxin-producing plankton may accumulate in such numbers so as to cause a harmful algae bloom (HAB). This closure was enacted when regular monitoring and testing as part of the Marine Biotoxin Monitoring Program determined that saxitoxin exceeded levels that required a closure,” said Matt Richards, a marine biologist with the DEC, in an email.

 A similar closure was enacted in April 2023 when mussels collected from a monitoring site in Jockey Creek also tested positive for saxitoxin. 

The issue was discovered during routine monitoring for HABs that produce marine biotoxins. New York State, Suffolk County and SUNY Stony Brook’s Gobler Lab have a network of HAB monitoring stations at key locations around Long Island, particularly within Suffolk County. These monitor for HABs that can produce marine biotoxins, Mr. Richards said.

This closure will not affect the fishing season for striped bass, which opened in marine waters April 15.

“Filter-feeding shellfish — clams, oysters, mussels, and scallops — can accumulate marine biotoxins, which can cause illness in shellfish consumers,” said Mr. Richards. “Carnivorous gastropods — whelks, conchs, moon snails — feed on shellfish and can accumulate biotoxins at levels that are hazardous to human health.” 

The DEC will re-open these areas as soon as possible, based on the results of laboratory analyses that will be conducted over the next few weeks. A recorded message advising harvesters of the status of temporarily closed shellfishing areas may be heard by calling 631-444-0480.

Maps of the affected areas and information about these temporary closures are available at Temporary Shellfish Closures. Information about marine biotoxins and paralytic shellfish poisoning is also available at HABs and Marine Biotoxins.