**ABSTRACT NOT FOR CITATION WITHOUT AUTHOR PERMISSION. The title, authors, and abstract for this completion report are provided below. For a copy of the full completion report, please contact the author via e-mail at warren.currie@dfo-mpo.gc.ca. Questions? Contact the GLFC via email at frp@glfc.org or via telephone at 734-662-3209.**

FATE OF VELIGER PRODUCTION AND TROPHIC LINKAGES WITHIN LAKE ONTARIO

Warren Currie¹, John Berges⁴, Kelly Bowen², and Marten Koops³

¹ Fisheries and Oceans Canada, 867 Lakeshore Rd, Burlington, L7S 1A1, 905-336-4823, warren.currie@dfo-mpo.gc.ca

² Fisheries and Oceans Canada, kelly.bowen@dfo-mpo.gc.ca

³ Fisheries and Oceans Canada, marten.koops@dfo-mpo.gc.ca

⁴ University of Wisconsin-Milwaukee, 3209 N. Maryland Ave., Milwaukee, WI 53211. 414-229-3258, berges@uwm.edu

September 2018

ABSTRACT:

The veligers of Dreissena (Zebra and Quagga Mussels) are now often the most numerous plankton group collected during the early summer to late fall in the Great Lakes, but the fate of this production is unknown. A pilot project was undertaken to determine if Dreissena veligers could be detected in the guts of zooplankton predators using polyclonal antibodies. Background zooplankton composition was collected from a range of sites around Lake Ontario in 2017 to compare with gut detections. Key zooplankton predator species were selected which are important to the fisheries food web: Bythotrephes longimanus, Mysis diluviana and Limnocalanus macrurus to be assayed. Veligers were detected in the guts of all three of these species using polyclonal antibody assays. This indicates that veligers are being incorporated into the pelagic food web. Highly desirable prey items (Daphnia galeata mendotae) had higher % gut detections for both Mysis and Bythotrephes even though they were at lower densities than veligers in the water column. This illustrates that polyclonal antibodies are useful for the investigation and future modeling of food web linkages in the Great Lakes.