Onshore nursery rearing of bivalve molluscs in Belgium

From October to April the growth of spat of Ostrea edulis, Crassostrea gigas and Venerupis semidecussata in an onshore nursery was recorded as a function of water temperature and food level. The results of this study indicate that even very eutrophic water, such as that of the Sluice Dock at Ostend, Belgium, does not provide enough microalgae to sustain growth of bivalve spat during winter, irrespective of whether the water is heated or not. It is necessary to supply additional food (cultured live algae). Food shortage for three months at higher temperature induced a stress situation resulting in high mortality rates, even after transferring all the spat into an optimal combination of temperature and food availability