Growth and mortality of cultured bay scallops in the Damariscotta River, Maine (USA)

Growth and mortality of hatchery-reared bay scallops, Argopecten irradians, were determined over an 18 month period (July 1994-December 1995) at two locations in the Damariscotta River, Maine, north of its natural distribution. Growth occurred primarily between May and October when mean water temperature exceeded 10 degrees C. Final mean shell height (56.3 mm) was significantly greater (p less than or equal to 0.0005) at the upriver site than at the downriver site in association with a higher mean water temperature. Cumulative mortality (43-49%) over this period occurred primarily over the winter months, in conjunction with mean water temperatures below 5 degrees C. Although it is possible to rear bay scallops to commercial size in Maine, the short growing season, high winter mortality, and costs associated with overwintering and fouling will likely deter commercial culture.