Evidence of shifting baseline and Fisher judgment on lane snapper (Lutjanus synagris) management in a Brazilian marine protected area

Abstract

The integration of knowledge from fishers and conventional scientific data is promising as a subsidy for the establishment of proper management procedures for fishing resources. In this context, the potential use of local ecological fisher knowledge from the Marine Extractive Reserve of Corumbau (MERC) in northeastern Brazil was evaluated regarding the shifting baseline of the lane snapper Lutjanus synagris. Semi-structured interviews were carried out with 222 fishers who identified L. synagris as the main fish resource used in MERC. The relationship between the maximum L. synagris weight caught on the best fishing day among fishers of different age categories was not significant (p = 0.306). However, older fishers significantly (p < 0.001) reported a higher time span since their best day catch. In addition, older fishers were significantly more perceptive (p = 0.013) to declining L. synagris abundance over time than younger fishers, who mostly reported that this species abundance is stable or has even increased over time. These results highlight an existing shifting baseline phenomenon for the L. synagris fishery in the region. Only 22.5% of the respondents, mostly younger fishers, expressed a need to establish specific management rules for the species. The proposed strategies for local L. synagris management included establishing a closed period, defining minimum catch sizes and creating new No-Take Zones specifically for this species protection. Trust bonds between fishers and fisheries managers, as well as scientists, require strengthening, and fisher knowledge can serve as a basis for building local targets for species conservation.