The significance of various environmental parameters for growth of the Iceland scallop, Chlamys islandica (Pectinidae), in hanging culture

Iceland scallops, Chlamys islandica (O.F. Müller), were grown in hanging culture at 3 different depths (2, 12 and 40 m below the sea surface) in a northern Norwegian fjord. The growth of the soft parts of the body and the shell increment were monitored throughout the growing season (March until September). At the same time, temperature, salinity, water density, current speed, chlorophyll, particulate organic matter (POM) and particulate inorganic matter (PIM) were monitored at each of the experimental depths. Analysis of the environmental data together with the growth data showed that growth differences between the experimental depths were essentially the results of differences in nutritional conditions for the scallops, defined by the relationship between PIM and POM in the water column. The results also showed that growth in Iceland scallops can be increased significantly by suspending the animals in a more favourable nutritional environment than that found on the natural scallop beds.