Селективность кутков тралов на промысле балтийской сельди.

Abstract

Research was conducted on the selectivity of trawls for Baltic herring in the Baltic and in the Riga Bay during the period from 1971 to 1974. The methods recommended by ICES have been applied. It was found that an increase in the mesh size of the cod-ends from 24 to 36 mm in the Riga Bay and from 32 to 40 mm in the Baltic increases the selectivity of herring trawls significantly. Relations are defined between the proportion of by-catch consisting of small fish, the modal value of the length distribution and the stock of the exploited population. The dependence-relations found can be applied to the calculation of minimum mesh sizes for the cod-ends which will meet the requirements of international fishery regulations.