Scientia Marina, Vol 72, No 3 (2008)

Comparison of diamond- and square-mesh codends in the hake (Merluccius merluccius L. 1758) trawl fishery of the Adriatic Sea (central Mediterranean)


https://doi.org/10.3989/scimar.2008.72n3451

Alessandro Lucchetti
National Research Council (CNR), Institute of Marine Sciences (ISMAR), Italy

Abstract


A traditional codend (40 mm diamond mesh) and an experimental codend (40 mm square mesh) made of 2.6 mm diameter knotless PA netting were tested on a commercial trawl net on a sandy-muddy bottom (~70 m depth) of the Adriatic sea in order to assess the size selectivity of European hake (Merluccius merluccius) and the reduction of the discards in a demersal multi-species trawl fishery. The catch was sorted as target species and bycatch and the selectivity with respect to European hake was investigated using the covered codend method. The square-mesh codend allowed a reduction of about 37% of the fraction discarded at sea. The mean catch obtained with the experimental codend was lower than that obtained with the traditional codend (about 14 kg per haul) but the short-term economic losses were low (~12%). The square-mesh codend was also more selective than the traditional codend, giving the juveniles of European hake a good chance of escape: the mean selection length (L50) was 7.60 cm in DM and 12.98 cm in SM. Moreover, the mesh configuration did not affect the gear’s performance. Thus, the square-mesh codend could be an easy, inexpensive and useful solution for a more sustainable management of the resources in Adriatic multi-species fishery.

Keywords


discards; square mesh; Merluccius merluccius; Adriatic Sea; fishery management; selectivity; bottom trawl

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