Assessing nine devices to reduce bycatch in the pink shrimp Penaeus paulensis fisheries: Lessons from field experiments with fyke nets

Abstract

The adoption of bycatch reduction devices (BRD) has been widely used to reduce bycatch in several fisheries worldwide, especially in trawl nets targeting shrimps. However, the efficiency of these devices has rarely been assessed in passive nets, such as fyke nets using light attraction. This study tested the efficiency of nine BRDs in a passive fyke net fishery performed in southern Brazil, targeting the pink shrimp Penaeus paulensis. The abundance of fishes, swimming crabs and shrimp was compared using the National Oceanic and Atmospheric Administration (NOAA) testing protocol across 1) three different light attraction colours; 2) two fisheye models; 3) two square-mesh models, and; 4) two grid models. A significant reduction in bycatch was recorded when using fisheye and square mesh, however it was also noticed an important reduction in target species. A reduction in total bycatch biomass was also recorded for both grid models (85 % for a grid angle of 50° and 61 % for a grid angle of 32°), with no significant reduction in target species when using grid angle of 32°. The extensive testing performed supports the ecological benefits of BRDs adoption and tools for management in small scale fisheries.