LAUSR

Assessing fish stocks harvested by small-scale fisheries is challenging. The lack of official fisheries data constrains the proper management of such fisheries. Thus, alternative sources of information are crucial to enrich data-poor fisheries. Here, we evaluated different sources of data for the mullet (Mugil liza) fishery, one of the most important but overexploited fisheries in Brazil. We gathered three alternative sources of catch data by artisanal fisheries: 14 years of self-reported catches by artisanal fishers across 24 municipalities; 16 years of catches by traditional beach seines mined from news outlets; and 13 years from a single community monitoring their beach seine catches. We tested whether alternative data sources follow the same trends of landing reports from systematic, official monitoring of the industrial fleet. We fitted Bayesian time-series models to test if environmental changes and stock abundance can predict these data. We found that only self-reported catches matched the official reporting trends, thereby improving our understanding of changes in the mullet stock. These findings reveal that self-reported catches by fishers provide reliable additional data useful for management. Self-reporting data are cost-effective, deals with the complexity of small-scale fisheries, and welcomes fishers as key stakeholders in management practices.