POPULATION-DYNAMICS AND ENERGY BUDGETS OF GREEN-LIPPED MUSSEL PERNA-VIRIDIS (LINNAEUS) IN A POLLUTED HARBOR

The population dynamics of Perna viridis (Linnaeus, 1758) in inner Tolo Harbour, Hong Kong were studied from May 1987 to September 1988. There were two recruitments per year, the first from July to September, the second from November to March. The dry gonosomatic index (DGSI) of a standard animal (70 mm) varied seasonally. The highest value was obtained in January 1988 (0.33), the lowest in September 1987 (0.14). The growth of P. viridis was highly seasonal and major growth was observed from May to November. An annual growth of 49.7 mm was estimated for the first year with a further increase of 24.2 mm in the second year and 9.3 mm in the third year. Mortality was high in summer, especially of large individuals during the post-spawning period. The standing biomass varied from 3.8 MJ.m-2 in July 1988 to 31.3 MJ.m-2 in May 1988. Annual production (May 1987-May 1988) of soma, gonad and shell were 11.67, 6.05 and 14.53 MJ.m-2.year-1, respectively. Respiration accounted for 77% of assimilation.