Fish production correlated with primary productivity, not the morphoedaphic index

Estimates of the biological production of entire lake fish communities were collected from the published literature on lakes covering a wide range of geographic areas and tropic status. Fish production is uncorrelated with the morphoedaphic index but closely correlated with annual phytoplankton production (r² = 0.79), mean total P concentration (r² = 0.67), and annual average fish standing stock (r² = 0.67). Conversion of phytoplankton into fish production is 100 times more efficient in oligotrophic lakes than hyper-eutrophic ones, but a much lower fraction of fish production can be channeled to sustainable yield in oligotrophic lakes. Sustained yields were frequently as little as 10% of the annual community fish production. -from Authors