Abundance, feeding ecology and growth of 0-group sea bass, Dicentrarchus labrax, within the nursery areas of the Tagus estuary

Abstract

The spatio–temporal abundance pattern of 0-group sea bass, Dicentrarchus labrax, was investigated between April 1995 and November 1996 by beam trawl surveys. The highest densities of D. labrax were recorded in shallow areas. Dicentrarchus labrax density was also significantly related to water temperature and salinity, but the variation pattern was not linear. The 0-group individuals of this species first occurred on the nursery ground in May and the highest densities were recorded in June. Diet of 0-group D. labrax was mainly composed of crustaceans, the most important food items being Decapoda, Mysidacea and Isopoda. Feeding activity increased during summer. Short-term variations were related to the period of the day and tidal cycle. The growth rate determined for 0-group D. labrax was higher than those reported for the UK and northern France, and was similar to those obtained in eastern Mediterranean.