Fishing from Space: Estimating Fishery Production Using Remote Sensing

The contribution of freshwater fisheries to global harvests is highly uncertain and likely underestimated.  Yet, the relative importance of freshwater fisheries grows as marine captures stagnate.  Based on empirical evidence relating fishery production to primary production at the global scale, we hypothesized that the production of freshwater fisheries in lakes may be estimated indirectly from measurements of chlorophyll.  We compiled a global dataset of in-situ fishery production and derived chlorophyll concentration for these lakes using the European Space Agency’s MEdium Resolution Imaging Spectrometer (MERIS) satellite data.  In-situ chlorophyll measurements for a subset of lakes were used to verify the ability of MERIS satellite data to remotely measure chlorophyll.  Then, we developed models of fisheries production as a function of remote-sensed chlorophyll data as well as watershed land-cover, climate, freshwater biodiversity, and other anthropogenic and socio-economic indicators.  Our modeling results suggest that remote-sensed chlorophyll data and regional climate and environmental variables may be used to estimate fisheries production when direct in-situ measurements are not available.  We expect these models to provide a check on the current estimates of global freshwater fish production.