Tropical Fishery Nutrient Production Depends on Biomass-based Management

This is a graphic titled fishing for nutrition. It reads across the top, "Ending overfishing is the best way to secure increased nutrient production from small-scale fisheries in the Western Indian Ocean." The bottom section under two pictures, one displaying one boat with lots of fish in the ocean and the second with several boats and not many fish in the ocean. The text reads, "Restored biomass provides significant increases in nutrient production. Functional traits influence nutrient density, but variation is small relative to human dietary needs."
This graphic shows how overfishing is detrimental to food security and how ending overfishing is the best way to secure increased nutrient production from small-scale fisheries.

Authors: Bryan P. Galligan and Timothy R. McClanahan


The need to enhance nutrient production from tropical ecosystems to feed the poor could potentially create a new framework for fisheries science and management. Early recommendations have included targeting small fishes and increasing the species richness of fish catches, which could represent a departure from more traditional approaches such as biomass-based management. To test these recommendations, we compared the outcomes of biomass-based management with hypothesized factors influencing nutrient density in nearshore artisanal fish catches in the Western Indian Ocean. We found that enhancing nutrient production depends primarily on achieving biomass-based targets. Catches dominated by low- and mid-trophic level species with smaller body sizes and faster turnover were associated with modest increases in nutrient densities, but the variability in nutrient density was small relative to human nutritional requirements. Therefore, tropical fishery management should focus on restoring biomass to achieve maximum yields and sustainability, particularly for herbivorous fishes.

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Published March 21, 2024