DYNAMICS OF JUVENILE SEA SCALLOP (PLACOPECTEN-MAGELLANICUS) AND THEIRPREDATORS IN BOTTOM SEEDING TRIALS IN LUNENBURG BAY, NOVA-SCOTIA

Thousands of juvenile sea scallop (Placopecten magellanicus) were rele ased on the sea bed in summer and winter at two sites (a topographical ly open and an enclosed site) along the southwestern coast of Nova Sco tia, Canada. Seeded and wild scallops and their predators (sea stars A sterias vulgaris and A. forbesi and rack crab Cancer irroratus) were m onitored by video and diver surveys over 17 mo. Following release, the density of seeded scallops rapidly decreased, and stabilized after 1- 8 wk; variation in final densities was greater between sites than betw een seasons of seeding. Seasonal temperature affected the rate at whic h the final densities were attained. Seeding effectively doubled scall op density at each site. Survivorship was similar to 10% due to loss f rom crab predation and dispersion of seeded scallops at the open site and similar to 1% due to mainly crab predation at the enclosed site. T emporal variation in abundance and spatial distribution of predators w as not correlated with that of seeded scallops, suggesting that predat ory mortality of seeded scallops was due to a functional response, rat her than an aggregative response of predators. Growth of seeded scallo ps was similar at both sites. The dynamics of the seeded scallop popul ations reflected the interaction of predation, dispersion, and growth.