Evaluation of Fish Communities Through Assessment of Zooplankton Populations and Measures of Lake Productivity

Abstract

Knowledge of zooplankton size structure and measure of lake productivity can facilitate interpretation of data from fishery surveys. Our findings demonstrate that, for small warm-water lakes containing predominantly centrarchids and percids, the size composition of the zooplankton community and growth and size structure of the fish community are closely correlated. Spatial-temporal differences between lakes suggest the fishery manager can obtain a useful measure of zooplankton size by sampling at deeper, offshore sites in August. Measurement of zooplankton size as an index of predator-prey balance in the fish community offers a simple, yet economical, approach for assessing the status of a fish population and determining management options. Comparisons of Fee's productivity index, zooplankton biomass, and catches of fish in variable-mesh gill nets indicate that lakes with a high productivity index generally support a larger biomass of planktivorous fish. Finally, evaluation of fish communities through assessment of zooplankton populations and measures of lake productivity has sound potential for future investigations and provides a rational basis for developing fish-management strategies.