A cross-lake comparison of crustacean zooplankton communities in the Laurentian Great Lakes, 1997-2016

摘要: Abstract Spring and summer open-water crustacean zooplankton communities were examined across all five Laurentian Great Lakes from 1997 to 2016. dominated by calanoid (lakes Superior, Huron Michigan) or cyclopoid Erie Ontario) copepods. Volumetric biomass of increased along an assumed trophic gradient (Superior, Huron, Michigan, Ontario; eastern, central western Erie), as did dominance cyclopoids cladocerans. Over the time series study, in lakes Ontario shifted towards greater calanoids similarity with Lake Superior. Trajectories changes different; however, reductions cladocerans accounted for most change Michigan while increases Leptodiaptomus sicilis behind Ontario. Shifts predatory cladoceran community Cercopagis pengoi occasional Bythotrephes longimanus, a species much more vulnerable planktivory, well appearance Daphnia mendotae daphnid previously consisting almost exclusively smaller retrocurva, suggest impacts reduced vertebrate predation. In contrast, strong correlations between chlorophyll point possible importance bottom-up forces those lakes. Large interannual shifts structure eastern basins intense but variable predation pressure. The may be approaching historic represented