Growth of the queen scallop (Aequipecten opercularis) in suspended culture: influence of density and depth

Abstract

The effects of density and depth on the growth of juveniles of Aequipecten opercularis held in suspended culture for 11 months in the Rı́a de Arosa (Galicia, NW Spain) were studied. The densities were 25, 50 and 100 spat per tray (200 to 800 spat m−2), and depths were 2, 7 and 12 m. Density and depth were found to affect growth. Although maximum growth occurred at 25 scallops tray−1, the growth recorded at densities of 50 and 100 scallops tray−1 was only slightly lower. Therefore, on a commercial scale, culture using the higher densities is recommended. There was less growth at 2 m than at 7 and 12 m, due to the surface layers having lower salinities during winter, higher temperatures during summer and lower concentrations of chlorophyll a throughout most of the year. Most growth took place between late autumn and early winter. After 11 months of culture, scallops of initial size 22 mm (shell height) and mean weight of 1.14 g reached a mean size of ≈58 mm and a mean weight of ≈26 g with mortality of less than 5%. The performance of A. opercularis in suspended culture makes it possible to consider this species as a good candidate for aquaculture in the Galician rı́as, NW Spain.