Fishery and stock assessment of sardine Sardina pilchardus (WALB.) in the Adriatic Sea

Abstract

    Sardine Sardina pilchardus (WALB.) is - together with anchovy Engraulis encrasicolus (L.) - one of the most important commercial fish species in the Mediterranean Sea and, in particular, in the Adriatic Sea. The mean value of the annual catch of sardine in the Adriatic Sea is around 50.000 t, in the period 1975-1996.

    Since 1975, the IRPEM is involved in research on sardine and anchovy abundance in the northern and central Adriatic Sea, by means of population dynamics methods. In this paper, the sardine stock biomass values estimated for the time interval 1975-1996 are discussed. These estimates were obtained using three methods based on different data inputs: Length Cohort Analysis (LCA), Virtual Population Analysis (VPA) and an ad hoc modified version of the DELURY model with recruitment index. A comparison between the biomass estimates derived from these methods was made. Values of biomass, as well as patterns over time, are consistent. In particular, strong fluctuations of biomass are evident. The possible effects of fishing effort on biomass were investigated and the stock-recruitment relationship analysed, in order to gain insight about the mechanisms underlying biomass fluctuations.