
Many rural communities around the world depend on fisheries as a key protein source. Sustainable fisheries management requires an understanding of the linkages between deforestation, erosion, sediment and nutrient transport processes that take place on land and flow through rivers but strongly affect coastal and marine environments.
Subsistence fisheries: Subsistence harvesting of ecosystem goods - food, fuel, fiber, and other basic resources - is a critical contributor to livelihoods in much of the developing world as well as in parts of developed nations. These ecosystem goods have been termed the “GDP of the poor,” since they provide employment and livelihoods for so many of the world’s poor while not being monetized as part of traditional national economic accounts. Societal dependence on subsistence fisheries, combined with the recognition that the world’s oceans are in crisis due to overfishing, pollution, and climate change strongly argues the case for more sustainable management of aquatic and marine resources. By mapping societal dependence on subsistence fisheries, we can demonstrate direct linkages between ecosystems and human well-being.

Subsistence fisheries models for Madagascar rely on global spatial datasets for fisheries, population density, and poverty, combined with data on national fisheries use. In Madagascar the species we modeled subsistence use of three species: sky emperor (Lethrinus mahsena), slender emperor (Lethrinus variegatus), and mangrove red snapper (Lutjanus argentimaculatus). Since underlying data are available for all nations, it is feasible to extend coverage of the ARIES subsistence fisheries model to other countries by simply accounting for the degree of dependence on specific fish species for each nation.