Bycatch is one of the main causes of mortality of marine megafauna over the world. In the coastal waters of southern Brazil, bycatch in gillnet sheries affects threatened species that use this region as a breeding and feeding area. The identi cation of hotspot areas of bycatch is necessary to design and prioritize e cient spatial-temporal closures that protect the largest possible number of threatened species of marine megafauna. In this context, the use of a multispecies approach is an important step towards planning effective sheries management measures. This study has two main objectives: 1) to identify hotspot areas of bycatch in gillnet sheries for the most threatened marine megafauna species on the continental shelf of Rio Grande do Sul (RS); 2) compare single species and multispecies mapping methods for the identi cation of these areas. To meet these objectives, data collected by onboard observers during shing trips in the coastal commercial RS-based gillnet eet, between 2013 and2015 and between 2018 and 2020, were analyzed. For the identi cation of the areas, hierarchical Bayesian spatio-temporal models were implemented, using monospeci c and multispeci c approaches and a weighting system for the conservation status of the species. Both approaches provide similar results, identifying three bycatch hotspots according to the analyzed time frame. Based on our ndings, we propose the creation of speci c no-shing areas in these regions. The suggested spatio-temporal closures would bene t several endangered species, also contributing to the recovery of sh populations.