What fishers' local ecological knowledge can reveal about the changes in exploited fish catches

This study focuses on a small-scale fishing community which primarily exploits fish in Tijucas Bay (Santa Catarina State, Brazil). The region is near a marine protected area and is also exploited by the industrial fishing fleet and shrimp fishers, however there is a lack of baseline and monitoring data about fisheries. We aimed to understand aspects of the historical dynamics of catches exploited by small-scale fishers and investigate their causes, through local ecological knowledge. We focused on four main target species: Genidens barbus, Micropogonias furnieri, Macrodon ancylodon and Mugil liza, which are the most important species targeted by fishing communities in the study area. We used face-to-face individual interviews with 34 fishers to identify changes in the current and past catches based on fishers perceptions. The current catches were smaller than the best previous catches for all species, suggesting a decline in catches. The perceived causes for the decline in catches were the industrial fishing, the shrimp trawling bycatch, and the overall increase in fishing effort. Fishers' knowledge has proved to be an important complementary tool in the monitoring of catches. Management actions are needed to overcome this trend in declining local fish catches and to ensure the livelihoods of small-scale fishers.