Abstract

Trawling operations for shrimp in the inter-tropical zone have associated the largest bycatch (BC) of fish and other species. In eastern Venezuela during 2006 artisanal landings of shrimp were estimated in 800 t and 2200 t BC, whereas industrial landings were estimated as 780 t shrimp, 5 000 t other species and 14 000 t BC. In order to reduce BC, structural modifications to the artisanal and industrial trawl nets were tested: escape panel with square mesh (SM), fish eye (FE) and double lower rope (DLR). In industrial trawls, the SM allowed a significant reduction of BC between 4 and 34%, with a decrease in the catch of shrimp of 57% and 19% in that of other species with commercial interest. The FE reduced BC by 62%, but also led to losses of 44% shrimp and 63% of other species. The DLR allowed a reduction of BC by 30%, while the catch of shrimp and other species were not affected or increased by 10 to 20%. With the artisanal system, the FE allowed reductions of BC between 50% and 89%, without affecting the shrimp catch. With the DLR, reduction of BC could reach between 70 and 90%, but shrimp catch was lowered up to 50%. It is recommended that the DLR be used in the industrial trawl and the FE in the artisanal one, in order to promote the reduction of bycatch and the sustainability of the shrimp and bottom fish fisheries.

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