Balancing conservation and utilization in spawning aggregation fisheries: a trade-off analysis of an overexploited marine fish

June 02, 2020

Although the management of fish spawning aggregations (FSAs) often requires a precautionary approach that initially emphasizes conservation, understanding the dynamics of spawning and interactions with fishing activities can help identify long-term management solutions that balance conservation with utilization. We designed a parsimonious, per-recruit model to evaluate the potential effects of seven time-closure scenarios implemented during the spawning season on egg production per recruit (EPR; a conservation metric) and yield per recruit (YPR; a fisheries metric) of Gulf corvina (Cynoscion othonopterus), a vulnerable marine fish that experiences persistent overfishing at its only known spawning grounds in the Gulf of California, Mexico. Three of the seven scenarios provided small-to-large increases in EPR (8–43%) accompanied by only small decreases in YPR (3–11%) that resulted in a sustainable fishery. Increased mortality of juveniles and small adults through targeted fishing or as bycatch in other fisheries, however, would erode the fisheries and conservation benefits of time closures. Our results demonstrate that information on spawning and fishing activities can be combined with stakeholder input to identify regulations that permit the sustainable harvesting of FSAs. Furthermore, the implementation of brief, temporal fishing effort restrictions can represent a viable, less restrictive alternative to marine protected areas for the management of FSAs.

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