Joining data-limited stock assessment and local ecological knowledge to inform tropical mullet management

Small-scale fisheries (SSF) constitute more than half of global fisheries. SSF fishers can offer vital insights into the life history characteristics of target species. Upholding the principles of good governance, the combination of conventional scientific knowledge (CSK) with local ecological knowledge (LEK) is pivotal to ensure the success of SSF management. In this study, we employed CSK and LEK to holistically assess the stocks of three commercially important mullet species in three estuaries in the Tropical Southwestern Atlantic, examining how both information sources can contribute to conservation and management efforts. For CSK, we employed a Bayesian size-based model to conduct a stock assessment grounded in prior information on life history parameters. For LEK, we conducted interviews with fishers, aiming to understand how they perceive stock status, and which factors affect these resources. The size-based model indicated significant fishing pressure, suggesting that two of the stocks are overexploited while one is operating at its maximum sustainable yield. LEK and CSK largely agree on mullet stock status but not on the causes of declines. CSK attributes the declines to high fishing pressure, while most fishers point out to environmental problems such as pollution. This underscores the importance of LEK to provide complementary information to fisheries management. By highlighting how LEK could complement SSF management, we argue that horizontal collaboration is essential in artisanal fisheries, allowing fishers, managers, and scientists an active voice in decision-making. We also identified strengths, weaknesses, opportunities, and potential threats to the mullet stocks in the region, allowing enhanced governance through collaboration among stakeholders and the scientific community.