Fresh Water Studies Commons^™

Direct And Indirect Effects Of An Invasive Planktonic Predator On Pelagic Food Webs, Angela L. Strecker, Beatrix E. Beisner, Shelley E. Arnott, Andrew M. Paterson, Jennifer G. Winter, Ora E. Johannsson, Norman D. Yan

Environmental Science and Management Faculty Publications and Presentations

The relative importance of top-down invader effects relative to environmental drivers was determined by sampling crustacean zooplankton, rotifer, and phytoplankton communities in a set of invaded and noninvaded reference lakes. The non-native invertebrate predator Bythotrephes had significant effects on zooplankton community size structure, rotifers, and phytoplankton taxonomic composition, but no significant effects on crustacean zooplankton taxonomic and functional group composition. Part of the variation in phytoplankton communities was explained by the presence of the invader. Because Bythotrephes is generally known to be a carnivore and to not consume phytoplankton, this effect is likely mediated by the zooplankton community’s response to …