Co-Principal Investigators: Edward Rutherford (CILER) and Radka Pichlová (U of M), and Henry A. Vanderploeg (NOAA/GLERL)

The main objective of this research is to clarify the feeding biology and role of a new invader of Lake Michigan, Cercopagis pengoi, in a plankton food web. Cercopagis shares many traits in common with Bythotrephes, another nonindigenous predatory cladoceran that invaded the Great Lakes basin earlier and caused serious changes. Therefore, the competitive and/or predatory relations between Cercopagis and Bythotrephes are investigated as well. To answer these questions a range of predation experiments were done, including videotaping and the results are being combined with the analysis of field observations on population dynamics of Cercopagis, Bythotrephes, and their prey.