engleski

CROATIAN BLUEFIN TUNA CATCHES IN THE ADRIATIC DURING 1999 THROUGH 2001 BY YEAR/MONTH/SIZE STRUCTURE

The weight compositions of bluefin tuna (Thunnus thynnus L.) catches from the Adriatic Sea during the period 1999 through 2001 by Croatian side are presented in this paper. Catch at weight composition was converted into catch at length using length-weight relationship calculated from published data for the Adriatic Sea. In addition, age composition estimates of these catches were done using age-length key obtained by spine reading. The assessment indicates a strong decline of the older ages groups from spring to summer months. Analyses of the catches made on the monthly bases show that majority of older age classes, that represent the most favourable catches, were fished in the month of April; 45% of the fish sized 21-50 kg and 58% of the fish sized 51-100 kg. However, in the months of July and August large quantity of smaller bluefin tuna were caught. These findings put reservations on the effects of existing measures to protect juveniles in the Adriatic Sea in which purse seining is prohibited for the month of May.

Size composition; purse seining; fishery statistics; bluefin tuna; Adriatic Sea

nije evidentirano