The offshore US Atlantic surfclam (Spisula solidissima solidissima) fishery is an economically important industry for coastal communities from Virginia to Massachusetts, generating $20 to $30 million of revenue yearly for the harvest of adults, however juvenile surfclams have recently gained popularity as an aquaculture target. Marketed as “New England Butter Clams,” juveniles can reach harvest size in one year or less. An important factor to consider is the selection of broodstock that are capable of producing seed suited for growth in near-shore aquaculture sites. Two partially sympatric but genetically-distinct populations of the Atlantic surfclam have been identified in New York and Massachusetts waters which may be growing differently, even when occupying the same habitat.
To understand the differences in these subpopulations, a larval experiment was designed to test the survival, growth, and settlement of each population and a hybrid cross. Larvae were reared in five different pH treatments to see differences in response to the varying ocean acidification conditions they may experience in coastal New England waters. Additionally, seed from both populations were grown in a reciprocal transplant experiment at two sites in Massachusetts, and their growth and condition measured throughout a year. Growth data from fertilization to settlement and then juvenile out planting will be presented. By understanding the range of environmental conditions suitable to existing surfclam populations, we aim to help “butter clam” farmers identify the best populations of broodstock for their businesses.