Inferring ecosystem impacts of a small-scale snapper fishery through citizen science data, productivity and susceptibility analysis, and ecosystem modelling

Abstract

The small-scale fishery targeting snappers in the Mexican Atlantic is data-limited since the best scientific information is insufficient to determine its status. Governmental (at regional level) and citizen science data (at a local scale) were used for fishery characterisation, emphasising the red snapper (Lutjanus campechanus). The characterisation, along with productivity and susceptibility analysis (PSA) and ecosystem modelling (Ecopath with Ecosim), were used to infer fishery impacts on the coastal ecosystem of Campeche and Tabasco, southern Gulf of Mexico (GOM). Red snapper official annual landings indicated relative stability after 2000 in all the Mexican states, with the highest average landings in Tabasco. Citizen science data showed that the fishery is highly selective for snappers (three species accounted for 83.4%) due to the use of species-specific gears in areas far from the shore (> 50 km). Although bycatch (n = 20 species) included five species with an IUCN risk category (VU, EN, and CR) and two sharks in CITES Appendix II, they represented a low catch percentage (< 2%) of the citizen science records. PSA suggests the red snapper had a moderate and three elasmobranchs high overexploitation risk. The ecosystem had a simple trophic structure and high resilience, with a strong energy flow exchange between three food web compartments. The overall results suggest that the small-scale fishery has a relatively low ecosystem impact in Tabasco and Campeche. However, systematic fishery monitoring to understand catch composition variations and collect more information on trophic web interactions is needed for future assessments.