Seasonality of Predatory Zooplankters Bythotrephes longimanus and Cercopagis pengoi in Lake Ontario

Session: Poster Session

Gabriella Doud, Cornell University, [email protected]
Kristen Holeck , Cornell Biological Field Station , [email protected]
James Watkins, Cornell University, [email protected]
Lars Rudstam, Cornell University Bio Field Station, Dept. of Natural Resources, [email protected]

Abstract

Cercopagis pengoi (fishhook water flea) and Bythotrephes longimanus (spiny water flea) are large, nonnative, predatory cladocerans in Lake Ontario. Originally from the Ponto-Caspian region in Europe, B. longimanus entered the lake in 1982 while C. pengoi came over a decade later in 1998, both via ballast water.  Both species have impacted other zooplankton in the lake and are often inversely related to each other. Lake Ontario is unusual in harboring both species.  Seasonal development of the populations of the two species varies, with Cercopagis typically peaking in summer and Bythotrephes in fall.  Seasonal cycles are evaluated through monthly CSMI (Cooperative Science and Monitoring Initiative) sampling (2008, 20013, and 2018) and US Biomonitoring sampling. This seasonal data for C. pengoi and B. longimanus was then compared to other long term but more time restricted (only August) time series to evaluate consistency in time series interpretations.