EFFECT OF STOCKING DENSITY ON GROWTH, PRODUCTION, AND SURVIVAL OF THE GIANT SCALLOP, PLACOPECTEN-MAGELLANICUS, HELD IN INTERMEDIATE SUSPENSION-CULTURE IN PASSAMAQUODDY BAY, NEW-BRUNSWICK

The effect of stocking density on the growth of juvenile giant scallops, Placopecten magellanicus (Gmelin, 1791) (Bivalvia: Pectinidae), was assessed for 1 year in Passamaquoddy Bay, N.B., Canada. Scallop spat (initial shell height=10-15 mm) were held in suspension culture (pearl nets) at six different stocking densities ranging from 136 to 818 spat m-2 (15-90/net). Scallops were sampled initially and at 5, 8, and 12 months in order to measure growth, yield, production, and survival. An inverse relationship was found between growth (shell height, meat weight, and whole weight) and stocking density, with a substantial amount of growth occurring at all densities. A similar relationship occurred between stocking density and production (kJ year-1) and yield (g) per individual. Overall survival was 91% and was not influenced by density. The optimal stocking density for giant scallops is dependent on the overall cultivation strategy and is thus influenced by the desired final market product, market size, type of grow-out technique, and timing of transfer from the pearl nets.