Progress to Improve NY’s Hard Clam Resiliency
Publications: Success Stories - Extension (2023)

Breeding QPX- and heat stress-tolerant clam strains at the Cornell Cooperative Extension Suffolk County Hatchery, summer 2022. Credit: Jade Wu/Stony Brook University


Antoinette Clemetson, NYSG Marine Fisheries Specialist, E:, P: (631) 632-8730

NYSG partnership is helping hard clam growers who operate under harsh environmental conditions 

Stony Brook, NY, March 23, 2023 - The hard clam, Mercenaria mercenaria, is the second most economically valuable bivalve species being farmed from Massachusetts to Florida. Hatchery production of high-quality seed that tolerate harsh biological and environmental conditions would help to expand and maintain this industry. Problems facing growers along the Atlantic coast include disease pathogens, harmful algae, prolonged heat wave, low salinity, icing, and pests. Collectively, these parameters result in significant mortality and economic loss that reduce growers’ profit. Access to selectively bred hard clam is a possible solution to bring relief to growers.

In 2022, New York Sea Grant (NYSG) continued its leadership under the Sea Grant Hard Clam Selective Breeding Collaborative (Hub) conducting genetic research to identify clam strains tolerant to these problematic conditions. 

Since publishing the clam genome characterizing the species’ genetic diversity in 2021, researchers submitted nine populations ranging from Maine to Florida for genome
re-sequencing. Two strains believed to resist Quahog Parasite Unknown (QPX) disease and heat stress were deployed in Massachusetts and New York field experiments to measure tolerance. Additionally, a student completed 10 weeks of science writing training with NYSG’s Community Engagement Internships (CEI) funding. The intern participated in a field trip at the Cornell Cooperative Extension of Suffolk County Hatchery, designed a public relations brochure and technical glossary, and created the script being used to produce the Hub’s first video.

Sea Grant Hard Clam Selective Breeding Collaborative research is assisting growers whose crop experiences QPX disease and heat stress mortalities.  This effort will ultimately breed clams to tolerate harsh conditions.


• National Sea Grant College Program (NY, NJ, MA, Woods Hole, VA, FL) 
• CCE Suffolk County Hatchery 
• Stony Brook University SoMAS Marine Animal Disease Laboratory 
• Rutgers University Haskell Shellfish Laboratory 
• Virginia Institute of Marine Science, University of Florida 
• Sorbonne University Roscoff Marine Station. 

Funding: National Sea Grant Office

More Info: New York Sea Grant

New York Sea Grant (NYSG), a cooperative program of Cornell University and the State University of New York (SUNY), is one of 34 university-based programs under the National Oceanic and Atmospheric Administration’s National Sea Grant College Program.

Since 1971, NYSG has represented a statewide network of integrated research, education and extension services promoting coastal community economic vitality, environmental sustainability and citizen awareness and understanding about the State’s marine and Great Lakes resources.

Through NYSG’s efforts, the combined talents of university scientists and extension specialists help develop and transfer science-based information to many coastal user groups—businesses and industries, federal, state and local government decision-makers and agency managers, educators, the media and the interested public.

The program maintains Great Lakes offices at Cornell University, SUNY Buffalo, SUNY Oswego and the Wayne County Cooperative Extension office in Newark. In the State's marine waters, NYSG has offices at Stony Brook University in Long Island, Brooklyn College and Cornell Cooperative Extension in NYC and Kingston in the Hudson Valley.

For updates on Sea Grant activities: has RSS, Facebook, Twitter, Instagram, and YouTube links. NYSG offers a free e-list sign up via for its flagship publication, NY Coastlines/Currents, which is published quarterly.

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