Tracking interactions: Shifting baseline and fisheries networks in the largest Southwestern Atlantic reef system

Abstract

Abstract Increasing evidence has revealed that different fisheries have collapsed around the world. This is generally more evident in countries that can maintain long‐term research and fisheries monitoring. When monitoring data are not available, alternative approaches to assess fisheries trends can be used, such as the local ecological knowledge of fishers. To investigate decadal changes in fisheries the local ecological knowledge of small‐scale fishers' was evaluated at four sites in Brazil: Porto Seguro, Prado, Alcobaça, and Caravelas. A fisher–fish network weighted by interaction strength was built to indicate the most relevant resources among fishers. The results suggest the occurrence of the shifting baseline syndrome among generations of fishers regarding commercially important fishes such as groupers and snappers. Handline fishers indicated a decline in catch per unit effort over 5 decades. Fisher–fish networks from Caravelas showed greater stability with stronger interaction strength, while Porto Seguro and Alcobaça networks were more fragile, and Prado network showed intermediate characteristics. Overfishing has affected high trophic level species that act as module hubs across the majority of sites. The fisher–fish network approach can be applied in data limited cases, improving the assessments of fisheries' dynamics (in space and time) and declining species.