The present invention relates to a fish-sorting system for sorting fish in a dragged fishing net (1), wherein the fish are actively sorted by means of - detection means (2, 3) which detect at least one size of a fish to be sorted； - a processing unit which compares the size detected by the detection means (2, 3) with the desired size； - a sorting device (4) which retains fish in the fishing net (1) of a size greater than the desired size and which releases fish of a size smaller than the desired size from the fishing net (1) on the basis of the comparison between the detected size and the desired size carried out by the processing unit.
