Date of this Version
The Prairie Naturalist· 42( 1/2): June 2010, pp 19-23
We compared two zooplankton collection gears, Wisconsin nets and column samplers, to evaluate the effectiveness of each gear in quantifying inshore and offshore zooplankton density and size structure in shallow, homogeneous lakes. Zooplankton densities (within gear) did not differ (P > 0.05) between inshore and offshore sites in either study lake, with the exception of Wisconsin-netted Cyclops sp. in Lake Goldsmith. Wisconsin net samples produced a higher mean zooplankton density than column samplers for Bosmina sp., Cyclops sp., and Daphnia sp. in East Oakwood Lake and for Cyclops sp. (inshore), Daphnia sp., and Diaptomus sp. in Lake Goldsmith. Zooplankton densities had greater variability (coefficients of variation) in 4 of 5 taxa collected with the Wisconsin net in both study lakes. Zooplankton size structure did not differ (P> 0.05) between gears in either study lake, with the exception of Diaptomus sp. in East Oakwood Lake. Our results suggest that column samplers have higher precision than Wisconsin nets when sampling common zooplankton species in shallow, homogeneous lakes.