engleski

Sardine (Sardina pilchardus, Walb.) stock assessment in the Adriatic Sea: 1975-2004

Sardine (Sardina pilchardus, Walb.) is an important commercial species of the Adriatic Sea. Stock of sardine living in northern and central Adriatic is shared between Italy, Slovenia and Croatia. The present assessment concerns the sardine stock of northern and central Adriatic Sea (GFCM GSA 17), pooling together data coming from Italy, Croatia and Slovenia. It has been carried out in the ambit of an extension of the AdriaMed-SP research programme. The annual catch of sardine for the three mentioned countries was obtained for the period 1975-2004. Also length frequency and age-length data and catch and effort data were available. Data were combined into fish age classes, so that catch-at-age data were obtained. That represented the basic input data of Virtual Population Analysis (VPA), employed for the present stock assessment. Annual values of mid-year stock biomass at sea, annual values of fishing mortality rate over the age class range 0-5, were obtained. Moreover, annual exploitation rates were calculated and compared with a threshold derived from literature and suggested for small pelagics. A continuous decline of stock biomass has been observed after the peak in the first half of 1980s. The present assessment shows a slight increase of the biomass and the exploitation rate is around the threshold. Therefore, it is recommended not to allow the fishing effort to rise. Furthermore, difficulties in obtaining economically satisfactory catches by fishermen were perceived in Italy.

Sardine; Adriatic Sea; Shared stocks; Catches; Stock assessment; Population dynamics methods; Virtual Population Analysis (VPA)

U tisku