New Estimation Method for Global Freshwater Fish Production

New Estimation Method for Global Freshwater Fish Production

Andrew M. Deines, David B. Bunnell, Mark W. Rogers, David H. Bennion, Whitney Woelmer, Colin N. Brooks, Amanda G. Grimm, Zachary Raymer, Michael J. Sachs, Robert A. Schuchman, & T. Douglas Beard

The direct assessment of freshwater fisheries production on the global scale is fundamentally hampered by the numerous and dispersed nature of lakes and the ubiquitous deficit of monitoring resources, even in developed countries. Our goal is to provide an alternative to the direct assessment of fisheries production based on ecological theory, empirical fisheries data sets, and remote sensing. Previous studies reveal a strong relationship between chlorophyll concentration and fisheries production across lakes, which we hypothesize can be used to develop predictive models of freshwater fishery production. By surveying published and gray literature, we compiled a database of over 700 lakes for which estimates of commercial, recreational, artisanal, subsistence, or fisheries-independent production estimates were available from around the world. We then used newly developed techniques in remote sensing of freshwater chlorophyll concentrations to develop predictive models of fisheries production. We used cross validation to demonstrate that the models make robust predictions for fish production in lakes across different types of fisheries, environmental, and climatic regions. These models could be used to supplement and “double-check” the results of direct assessments. Our long-term goal is to use these models to provide a novel assessment of freshwater fisheries production at the global scale using global distributions of remotely sensed chlorophyll data.

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