Contact: 

Antoinette Clemetson, NYSG Marine Fisheries Specialist, E: aoc5@cornell.edu, P: (631) 632-8730

NOTE: Please see "More Info" section below for a September 2023 update.

Stony Brook, NY, May 1, 2023 - Mercenaria mercenaria or hard clam is a very important species for the health of the economy and the marine food web. 

Growers along the eastern seaboard experience mortality related loss in their hard clam inventory for several reasons. 

• In northern areas, the pathogen known as Quahog Parasite Unknown or QPX creates problems on shellfish farms from Massachusetts to Virginia. 

• In Florida heat stress during the summer can result in mortalities of larger clams reaching harvest size, these events result in lost revenues for growers. 

Thus, the Sea Grant Hard Clam Selective Breeding Collaborative (Hub) aims to improve the aquaculture industry on the Atlantic coast, by finding and establishing more resilient lines of clams. Researchers have been studying the clam’s genome for the identification of naturally occurring strains that are resistant to these stressors. 

For more about the Hub, visit www.nyseagrant.org/hardclamhub.

Full Video Transcript

00:13
Mercenaria mercenaria or hard clam is a very important species for the health of the economy and the marine food web. Growers along the eastern seaboard experience mortality related loss in their hard clam inventory for several reasons. In northern areas, the pathogen known as Quahog Parasite Unknown or QPX creates problems on shellfish farms from Massachusetts to Virginia. In Florida heat stress during the summer can result in mortalities of larger clams reaching harvest size, these events result in lost revenues for growers. Thus, the Sea Grant Hard Clam Selective Breeding Collaborative (Hub) aims to improve the aquaculture industry on the Atlantic coast, by finding and establishing more resilient lines of clams.  Researchers have been studying the clam’s genome for the identification of naturally occurring strains that are resistant to these stressors. 

01:06
Now, what is a genome? A genome is all the genetic information stored in DNA that describes a living organism and this genome makes us who we are. But why is it so important to study this genome in this project?  The genome controls the characteristics or traits in an organism. The genome is key for allowing scientists to identify parts of the DNA that control responses against QPX disease and heat stress. The method being deployed identifies an exact location also known as a genetic marker on a chromosome that controls specific traits. A trait is the expression of a gene and this can have physical, metabolic or immune characteristics. Seemingly minor variations in these genetic markers can create major differences in traits.  

01:52
A team of researchers has successfully completed the first steps to identify these genetic variations at the DNA level within the clam genome that controls response to QPX disease and heat stress. Scientists have sequenced the hard clam genome and discovered millions of small variations in DNA called Single Nucleotide Polymorphisms, or SNPs. In a few minutes, we will describe how our researchers use SNPs to select the best clams to produce the next generation. Genetic selection is expected to be more precise and efficient than traditional selective breeding. This selective breeding will produce genetic improvements so hard clam growers can reproduce these specific traits in future generations of their crops. When completed, this selective breeding method being developed under this project will be widely applied across the hard clam aquaculture industry. 

02:47
Many areas of the domestic food industry use selective breeding to increase production. For example, this method was introduced on dairy farms to increase the amount of milk produced per cow in the United States since 1999. Recent statistics from the US Department of Agriculture estimate that dairy cows yield 10% more milk each day. Selective breeding is different from genetically modified organisms or GMO. GMO usually involves the introduction of foreign genes that didn't exist previously, whereas selective breeding is based on naturally occurring variations already in the organism. 

03:23
What has the Sea Grant Hard Clam Selective Breeding Collaborative Research accomplished thus far? 

03:29
Accomplishment number one: Decode the Genome. To decode the hard clam genome researchers began with one clam and performed genetic sequencing to identify the DNA composition and protein coding sequences and used these results as reference for future population genetic studies. 

03:48
Accomplishment number two: Identify Population Genetic Diversity. Researchers successfully mapped DNA for nine distinct hard clam populations ranging from Maine through Florida, and compared these results with genetic code from the reference organism to determine differences in their DNA sequence. Doing so a genetic code library was constructed to document all genetic variations that were detected in hard clam populations with a focus on what is called Single Nucleotide Polymorphism or SNP.  SNPs are extremely important since changes in a single position in a genetic code can lead to a change in the amino acid sequence and protein activity.

04:31
Accomplishment number three: Genotyping tool development. Researchers then selected the most informative SNPs to build SNP arrays, which are powerful and cost-effective genotyping tools that are now being used to identify clams that are resistant to various stressors. Doing so scientists can identify genetic fingerprints of clams that resist disease and environmental stress. These genetic fingerprints can then be used to select broodstock for selective breeding using resistant strains. In this phase of the project, researchers are applying these snip array tools to select strains that are tolerant to heat and QPX. 

05:11
While it has taken four years to accomplish these milestones, the results and genotyping tools provide the capability to improve lineage that are being cultivated by the industry. There is still more work to be done, but we hope to soon identify resilient strains that would improve clam farm viability and from this ensure the availability of high-quality seed to growers.


More Info: CCE Suffolk County's Marine Program News Magazine Features Sea Grant's Hard Clam Video



Riverhead, NY, September 18, 2023 - On the Water + In the Field is a news magazine show produced by the Cornell Cooperative Extension Marine Program (CCE Marine Program) that seeks to educate on current projects, issues, and research pertaining to our marine environment. 

In Episode #23, the CCE Marine Program takes you out to Shelter Island for an update on our shellfish and habitat restoration efforts from a grant provided by the Town of Shelter Island, NY's Community Preservation Fund. 

Next, they travel to Tiana Bay Side Facility and introduce you to Tiana Turtle and then, starting at 15:18 and running until 21:06, highlight some technical hard clam research led by New York Sea Grant called the Hard Clam Selective Breeding Collaborative. 

You’ll also get an update on what's been going on with the Back to the Bays initiative, including an introduction to featured artist Scott Bluedorn Fine Art and Illustration. 


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: www.nyseagrant.org has RSS, Facebook, Twitter, Instagram, and YouTube links. NYSG offers a free e-list sign up via www.nyseagrant.org/nycoastlines for its flagship publication, NY Coastlines/Currents, which is published quarterly.