The Iceland scallop, Chlamys islandica (O.F Müller), in Breidafjördur, west Iceland. III. Growth in suspended culture

Abstract

During two years, from September 1989 to September 1991, a study was carried out to evaluate the potential of pearl net cultivation of Iceland scallop, Chlamys islandica (O.F Müller), in Breidafjördur, west Iceland. In September 1989 1-year-old spat (mean height 9.8 mm±2.0 s.d.) were transferred from collectors to pearl nets suspended from flotation at 6–8 m depth. Shell increment, chlorophyll- a, temperature and salinity were monitored each month at the experimental site. During the second year in the pearl net culture, growth of soft parts of the body was also measured. By September 1990 the scallops had an average shell height of 24.6 mm±6.0 s.d. and in September 1991, three years after settlement, a height of 43 mm±8.3 s.d. was reached. Growth rate was related to food availability (measured as chlorophyll- a). During both years of the investigation height-specific growth rate reached a maximum (0.7% day −1 and 0.3% day −1, respectively) in early spring and again in summer, but it gradually decreased as the scallops grew older. The growth season lasted from March to October during both years of investigation. The results showed that the growth of Iceland scallops can be increased markedly by suspending the animals in hanging culture in more favourable environmental conditions than found on the natural scallop beds. The feasibility of cultivating Chlamys islandica in Breidafjördur is discussed.