CCE-Suffolk Confirms Fourth Straight Year of Mass Die-Off of Peconic Bay Scallops

Scientists at Riverhead-based Cornell Cooperative Extension of Suffolk County (CCE Suffolk) have confirmed that a mass die-off of adult Peconic Bay scallops occurred during the months of June and July, the fourth consecutive year of historically low scallop harvests.

Aquaculture experts from the CCE Suffolk Marine Program and Stony Brook University, however, are jointly undertaking two innovative, breeding initiatives that hold forth hope for the recovery of the East End scallop industry.

CCE researchers attribute the mass die-offs to at least three factors: high disease levels exacerbated by higher water temperatures, low levels of dissolved oxygen, and the physiological stress of spawning by adult scallops amid the higher water temperatures.

For many years, Suffolk County has played an instrumental role in sustaining the region’s scallop industry through large-scale restoration programs. For more than a decade, the County has provided funds to CCE Suffolk to create and maintain a large-scale, spawner sanctuary in Orient Harbor that has helped sustain and strengthen the scallop harvest.

“Bay scallops are a historically important fishery in the region dating back to our founders. With this in mind, Suffolk County has supported the work of Cornell Cooperative Extension to restore the scallop populations since 2004,” said Suffolk County Executive Steve Bellone. “While recent harvests have been disappointing, I am confident that CCE Suffolk and their partners will develop the appropriate methods to bring back a sustainable harvest.”

“Cornell Cooperative Extension is proud to be partnering with Suffolk County and Stony Brook University to restore our area’s scallop harvest to its former vibrancy,” said Vanessa Pino Lockel, executive director of Cornell Cooperative Extension of Suffolk. “Our local fisheries play a vital role in the Suffolk County economy, and CCE’s first-class team of marine experts is dedicated to helping these fisheries attain their full potential.”

Thanks to CCE’s restoration efforts, the scallop catch had once seen a thirty-fold increase since the launch of the County-supported program. The surge in scallop harvests generated millions of dollars of income for local baymen, as well as higher revenues for such associated businesses as fish markets and restaurants.

“Without the work of CCE and the financial backing of Suffolk County,” said William Caldwell, president of the Southampton Baymen’s Association, “this resurgence of Peconic Bay scallop populations and fisheries may never have occurred.”

“Scalloping is what baymen love to do. It’s a passion, not a job. Baymen count on the scallop fishery to put food on the table,” said Mike Inzone, a bayman and aquafarmer from Ronkonkoma. “Without Cornell Cooperative Extension’s work to understand why scallops are dying – and without their work to restore them and give us hope – there will be nothing to sustain this passion.”

Aiming to trigger a resurgence in the scallop population, CCE Suffolk is now working on two genetic-driven projects under the leadership of Bassem Allam, a professor of marine sciences at Stony Brook. The projects are evaluating selective breeding as a strategy to mitigate the extensive die-offs.

The first initiative began in April and May when CCE aquaculture specialist Harrison Tobi and shellfish ecologist Stephen Tettelbach spent many days scuba diving in search of adult scallops that had survived the mass die-off of 2021. So far, these selected scallops, known as “broodstock,” have been used by CCE to produce more than 20,000 new scallops for continued genetic work and more than 240,000 for ongoing restoration work supported by Suffolk County.

“I truly believe this approach represents our best hope for the longer-term sustainability of the Peconic Bay scallop population and fisheries,” said Mr. Tettelbach.

The second initiative, spearheaded by Mr. Tobi and the CCE Suffolk shellfish hatchery, plans to spawn adult bay scallops in the fall. Work to date suggests that fall offspring appear to survive the winter better than those born earlier in the year. This new research will examine whether fall-spawned scallops can endure summer conditions and survive to the following fall harvest season.

“There are many baymen from Brookhaven Town that participate in the Peconic Bay scallop fishery in the fall and winter,” said Tom Gariepy, a commercial fisherman from Blue Point. “We all appreciate the continued restoration work of CCE Suffolk and the development of these new genetic lines.”

Despite the mass die-offs of adult scallops, enough are still reproducing to sustain Peconic Bay populations. With mass mortalities occurring during the summer, however, very few adult scallops are able to survive to November, when the harvest season opens. Annual scallop catch in 2020 and 2021 averaged only three percent of those in 2017 and 2018.

Owing to this bleak forecast, the fall harvest season is likely to leave many local baymen without an important source of revenue.

“It’s devastating. In some years, bay scallops represent fifty percent of our income,” said Peter Wenczel, a bayman from Southold. “There are a lot of people who are going to be really hurting.”

The 2022 die-off was confirmed by dive surveys of natural Peconic Bay scallop populations and the monitoring of hatchery-reared scallops held in cages at several locations. The surveys were led by Mr. Tobi and Mr. Tettelbach.

The succession of mass scallop die-offs over the last four years contrasts sharply to those of the prior decade when the large-scale Peconic bay scallop restoration program headed by CCE Suffolk and funded by the Suffolk County Water Quality Protection and Restoration Program brought populations back from historically low levels to the watermark years of 2017 and 2018. Those two years saw the highest abundances since before brown tide algal blooms in the 1980s and 1990s had decimated scallop stocks.

Since 2019, CCE Suffolk scientists have worked closely with researchers at Stony Brook University to better understand the causes of scallop die-offs. They have intensively monitored wild and planted scallops from Flanders Bay at the western end of the Peconic system to Napeague Harbor to the far east. This research has been coupled with the ongoing monitoring of environmental parameters, as well as pathological analyses of a bay scallop parasite recently discovered by Dr. Allam and his team at Stony Brook University.

While the New York State bay scallop sector has been officially declared a disaster and has qualified for federal disaster relief funding, this financial support for baymen has thus far failed to materialize.

For more information about the Cornell Cooperative Extension Scallop Restoration Program, visit www.ccesuffolk.org/marine/aquaculture/scallop-program or www.ccesuffolk.org/marine and on social media at @ccemarineprogram.

Inquiries regarding the CCE Marine Program’s scallop restoration programming can be directed to Harrison Tobi at [email protected] or 802-310-3761.