Linking habitat conditions and growth in the European anchovy ( Engraulis encrasicolus)

Age structure and growth parameters for the anchovy fishery, Engraulis encrasicolus, were estimated for the first time in the Strait of Sicily. Environmental factors including sea surface temperature and chlorophyll concentrations were considered in order to explain differences in growth parameters between different areas. The sampling was carried out from May 2000 to October 2001 on board commercial fishing vessels. The age structure of the catches was dominated by the second-year-class (55–63%) and the first-year-class (30–41%), whereas the 0-year-class (1–5%) and the third-year-class (3–5%) represented a small proportion of the catches. The von Bertalanffy growth model and back-calculation analyses were applied to estimate anchovy growth parameters using the FiSAT program. There were not significant differences between males and females, pooled mean parameters were L ∞=18.6 cm, k=0.29 per year and t 0=−1.81 years. The estimated parameter k of the Sicilian anchovy was at the lower end of the range observed for this fish species in different areas, ranging from 0.26 (Algeria) to 2.44 (north Adriatic sea). Average chlorophyll concentrations (from 1997 to 2002), and sea surface temperatures (from 1971 to 2000) derived from satellite images for each area, explained the 88% of the variance observed in the growth of the anchovy between the areas. As fish production results basically from recruitment success and fish growth, we conclude that specifically for each species, relationships between fish growth with habitat conditions (mainly primary productivity and temperature) could be used to assess the potential fishery yields of a region, in addition to considering all factors that potentially could affect recruitment success in that region.