Current Articles | Categories | Search

Newsletter February 2015

Fish overboard! Mapping discards in Belgian fisheries serves to evaluate the effects of mitigation measures.

Before discard reduction measures can be evaluated, a detailed baseline study on current discarding practices must come first. ILVO has composed a "discard atlas" based on the available long-term data on discards of fish on commercial vessels. These data on the variations in discarding form the basis for evaluating the policy-making processes aimed at preventing waste in fisheries.

discard atlasIn commercial fisheries, a portion of the catch is returned to the sea. Discarded fish are either too small to sell legally, they belong to a species for which the fisher has no quota, or because of certain catch composition rules. Discarding can also happen because the fish has little economic value such as non-commercial fish, damaged fish or small (but above the legal minimum size) commercial fish. Society perceives discarding as wasteful and the societal and legal pressure is increasing. The European Commission has recently approved a “landing obligation” or “discard ban” aimed to reduce the number of discards. Starting in 2016, this landing obligation will be introduced gradually for the Belgian fleet. To address the issue of discards in fisheries, discard practices should first be evaluated to identify the specific problems. ILVO has therefore documented the current knowledge about discards in the Belgian fleet. A number of strategies were then proposed to reduce discards.

The documentation of discards was based on the long-term data on discards in the Flemish commercial fleet gathered by ILVO observers at sea. These observers analyse the landings and discards of the commercial fleet. They collect data on the catch composition, vessel and gear, mesh size, selectivity adjustments, fishing grounds and climate. Based on these data, discard estimates are made for commercial species based on age, sex, region, quarter and fishing method. The discard ratio is calculated for each of those categories as the proportion of the catch: discard ratio = discards / (discards + landings).

The results show that discards are fairly low for a number of species such as sole, turbot and brill. For some other species (e.g. plaice, dab and whiting) discards are quite high in certain areas. However, there appears to be a wide variation in discards between different years and different fishing grounds. The discard atlas documents this variation and may form the basis for strategies to reduce discards and to achieve more sustainable fisheries.

Funding: EFF (European Fisheries Fund)
Term: 2014 - 2015
Contact: Bart Vanelslander