Peconic Bay scallops have suffered catastrophic die-offs.

Peconic Bay scallops have suffered catastrophic die-offs. Credit: Randee Daddona

The annual Peconic Bay scallop die-offs that have rippled across the East End since 2019 took place again in 2023, scientists said this week, but there’s hope on the horizon from a recent upsurge in nearby Moriches Bay scallops.

There also may be new promise from scallops that are spawned in the fall rather than the more typical summer, when warming waters and a devastating parasite are known to stress the iconic Peconic scallops.

Biologists at Cornell Cooperative Extension’s Marine Program during their August survey of 21 scallop beds from Flanders to Orient Point found a total of only around 30 to 40 adult scallops in the areas, with some showing no scallops at all.

It’s a phenomenon that has continued each year since the recent round of scallop die-offs began in 2019 — one that has rippled through an East End fishing community that long relied on the shellfish for year-end revenue. The Long Island scallop season opened the first Monday in November.


  • The annual Peconic Bay scallop die-offs took place again in 2023, but there’s hope from a recent upsurge of nearby Moriches Bay scallops.
  • Scientists say the Moriches Bay scallops may be more resilient than their Peconic relatives and that they are considering transplanting some to Peconic Bay as a test.
  • There also may be new promise from scallops that are spawned in the fall rather than the summer, when warming waters and a parasite are known to stress the Peconic scallops.

But there’s hope to rebuild and improve the population with the finding that bay scallops in Moriches Bay may be more resilient than their Peconic Bay relatives, said Harrison Tobi, a marine biologist who specializes in bay-scallop aquaculture and restoration.

“They could have a higher survival rate in Moriches Bay due to some genetic trait,” he said, adding that his team was “surprised by the amount of scallops people are catching” in Moriches Bay. “And I know the baymen are pretty surprised and pleased. They are catching them in pretty good numbers.”

Tobi said Cornell wants to seize the opportunity by transplanting those scallops into the Peconic Bay population. The concept, still in the planning stages, would be to use a subpopulation of 60 to 100 adult scallops to spawn a new-year class and transplant them selectively in the Peconic. “We’re working to get them now,” he said.

The plan is desperately needed. Tobi said that while some baymen are having luck catching scallops in select areas of Peconic and Gardiners bays, “It’s nothing compared to what it used to be.”

The value of commercially landed scallops, which reached a recent high of $1.5 million in 2018, dropped to $382,000 in 2022, $61,000 in 2021 and $99,000 in 2020, Tobi said. 

“I can’t even imagine the impact it must be having on baymen and their families,” he said.

Dive surveys this year indicated “very low numbers” of scallops in Cornell’s 21 sample areas. Impacts are not specific to any part of Peconic Bay, suggesting that environmental impacts of any one area are not the cause, he said.

Rather, Cornell and Stony Brook University researchers have isolated a microparasite as the likely cause of the die-offs, an infection likely exacerbated by a “perfect storm” of warming waters tied to climate change and low oxygen levels at a critical time for the scallops — the summer spawning season.

“The parasite does seem to be the ultimate driver, in addition to climate change and spawning stress in these mass die-offs,” Tobi said. “The parasite appears to be the straw that broke the camel’s back.”

Tobi said new research is testing another theory that could prove promising: propagating generations of scallops bred in the fall rather than the summer. Cornell has begun a small-scale project to test the resilience of fall-spawned scallops to see how they survive the summer rigors. Early results show they appear to have a “significantly higher survival rate and a lower parasite level in the fall of the year,” Tobi said.

“I’m very hopeful,” Tobi said of plans to improve scallop survival. “We figured out the cause and now we can start working toward a solution.”

Some seafood shops were surprised to see the prevalence of Moriches Bay scallops.

"Every single bay scallop we sell is coming from Moriches Bay," said Joe D'Ambrosi, a chef and fish cutter from Mill Road Seafood in Westhampton Beach. The shop was well stocked with the scallops Wednesday at a price of $41 a pound. 

“This is probably the most I’ve ever seen from Moriches Bay,” said Nino Locascio, one of the owners of Mastic Seafood in Mastic. He said the amounts had been larger earlier this month, and the scallops were “big and healthy and beautiful.” The numbers have tapered off some, he said, but he continues to have them for sale.

Locascio said local thinking is that the health of Moriches Bay, including small areas with more eel grass and better water quality, may be the reason for the scallop increase. Some fishermen began finding them in higher numbers in March. The season ends in April.

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