Bycatch reduction in shrimp trawl fisheries using a modified net design

This study tested the efficacy of a modified trawl net in the brown shrimp (P. californiensis) fishery in northern Peru. The modified net was designed to improve selectivity by incorporating 60 mm, 50 mm, and 36 mm mesh sizes, modifications to the net mouth were made to achieve a more pronounced catenary curvature, and the net was constructed primarily from polyethylene in various sections to reduce its overall weight. To further enhance selectivity, an additional footrope was incorporated to facilitate the exclusion of certain benthic species, such as soles, starfish, and other bottom-dwelling organisms. A square mesh window was added 60 cm from the bottom center of the net mouth to allow the escape of snails and crabs. The modified net reduced bycatch by 35% and discards by 50%, while the catch of target species remained unchanged. The reduction in bycatch was not significantly different for species of fish, although catch of this species group was reduced by 24%.