Effects Of Eutrophication On The Fish Communities Of Florida Lakes

From an analysis of the trophic status and fish populations of 22 Florida lakes, total fish biomass is low in oligotrophic lakes, increases to a maximum in mesotrophic-eutrophic lakes, and fluctuates around the maximum value in hypereutrophic lakes. Total fish density likewise is low in oligotrophic lakes and increases to a maximum in mesotrophic-eutrophic lakes; but unlike biomass, fish density declines as lakes become hypereutrophic and gizzard shad becomes the dominant species of fish. Sport fishes reach maximum biomass and optimum densities in mesotrophic-eutrophic lakes with a total nitrogen concentration of 1.2 mgll and a chlorophyll a concentration of 11.0 ugll, but suffer adverse effects with further enrichment.