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Anchovy (Engraulis encrasicolus, L.) stock assessment in the Adriatic Sea: 1975-2004

Anchovy (Engraulis encrasicolus, L.) is one of the most important commercial species of the Adriatic Sea. Stock of anchovy living in northern and central Adriatic Sea is shared between Italy, Slovenia and Croatia. The present assessment concerns the anchovy stock of northern and central Adriatic Sea (GFCM GSA 17), pooling together data coming from Italy, Slovenia and Croatia. It has been carried out in the ambit of an extension of the AdriaMed-SP research programme. The annual catch of anchovy for the three mentioned countries was obtained for the period 1975-2004. For the same time interval, fishing effort data and length frequency and age-length data were available. These data were combined into fish age classes, so that catch-at-age data were used as basic input of Virtual Population Analysis (VPA), employed for the present stock assessment. Annual values of mid-year stock biomass at sea, annual values of the fishing mortality rate over the age class range 0-3, were obtained. In addition, on the basis of the mentioned fishing mortality rates and natural mortality rate, annual exploitation rates were calculated and compared with a threshold derived from literature and suggested for small pelagics. Stock biomass of anchovy dropped at very low level in 1987. After this collapse a slow, but continuous recovery of biomass took place. The present assessment shows a stronger recovery during last two years. Due to high biomass fluctuations of small pelagics it is recommended to maintain the current level of fishing effort.

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

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