Zoobenthic Distribution and Biomass in the Turkey Lakes
The composition of the benthic fauna in the four oligotrophic lakes of the Turkey Lakes Watershed was dependent on the absence offish, depth, and hypolimnetic oxygen concentrations, rather than the chemical gradient in the watershed. Biomass in the littoral zone was greatest in the fishless upper lake of the watershed (0.35 g∙m−2), dominated by amphipods and predatory insects, which replaced fish as top predators in the lake. The shallowest lake (Wishart) had the lowest lakewide biomass (199 g∙ha−1) and estimated production of the four lakes, in spite of having the greatest algal and fish production in the watershed. The biomass present below 2 m was greater in the lower two lakes, dominated by the Chironomidae. Little Turkey Lake had the greatest area weighted lakewide biomass (843 g∙ha−1) and estimated production, as a result of a large population of Chironomus spp. in the hypolimnion. Batchawana Lake, the upper lake in the watershed, had the lowest benthic populations due to severe oxygen depletion in the hypolimnion.