ABSTRACT
Lake St. Clair was the early focal point for invasion of zebra mussels (Dreissena polymorpha) in North America in the 1980s (Herbert et al. 1989, Carlton 2008), and dreissenid populations have been present in this lake at varying abundances ever since (Nalepa et al. 1996, Hunter and Simons 2004). Lake St. Clair has historically been an important fall concentration area for waterfowl (Bookhout et al. 1989, Prince et al. 1992), especially diving ducks such as lesser scaup (Aythya affinis), greater scaup (Aythya marila), canvasback (Aythya valisineria), and redhead (Aythya americana). During fall migration, these ducks rest and acquire foods from Lake St. Clair as one of many stopovers in route from breeding to wintering areas (Bellrose 1976).
