Voices from the Coast: Artisanal Fishers’ Knowledge of the Lebranche Mullet ( Mugil liza ) in Southern Rio de Janeiro

Local Ecological Knowledge (LEK) of artisanal fishers can provide valuable insights into the ecology of fish species. The lebranche mullet ( Mugil liza ) is a key resource in Brazilian artisanal fisheries, yet gaps remain in scientific knowledge regarding its bioecology. This study integrated the LEK of 198 fishers from 41 Caiçara and Quilombola communities in Sepetiba Bay (SB) and Ilha Grande Bay (IGB), two important fishing territories in southeastern Brazil. We hypothesized that fishers’ knowledge would reveal consistent and interconnected perceptions regarding mullet reproductive timing, migratory behavior, and responses to anthropogenic pressures, converging with while also complementing established biological understanding of the species. Data were collected through semi-structured interviews using the snowball sampling technique. Responses were analyzed quantitatively using proportions and through lexical analyses with the software IRAMUTEQ, complemented by full transcriptions of selected narratives. Most fishers reported that M. liza reproduces in winter, in agreement with the literature; however, many also indicated summer reproduction in SB, suggesting the possible presence of a resident metapopulation. Fishers also reported the emergence of infestations by Cymothoidae parasites in both bays, as well as a decline in species abundance, mainly attributed to industrial pollution and increased fishing pressure associated with the commercial export of M. liza roe. These findings reinforce the importance of integrating fishers’ LEK into fisheries management and conservation strategies, particularly in regions facing multiple anthropogenic pressures.