GROWTH AND MORTALITY OF CULTURED BAY SCALLOPS IN THE DAMARISCOTTA RIVER, MAINE (USA)

Growth and mortality of hatchery-reared bay scallops, Argopecten irrad ians, were determined over an 18 month period (July 1994-December 1995 ) at two locations in the Damariscotta River, Maine, north of its natu ral distribution. Growth occurred primarily between May and October wh en mean water temperature exceeded 10 degrees C. Final mean shell heig ht (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 thi s period occurred primarily over the winter months, in conjunction wit h mean water temperatures below 5 degrees C. Although it is possible t o rear bay scallops to commercial size in Maine, the short growing sea son, high winter mortality, and costs associated with overwintering an d fouling will likely deter commercial culture.