Alewife (Alosa pseudoharengus) density as a predictor of open water utilization by walleye (Sander vitreus) in Otsego Lake, NY

Walleye (Sander vitreus) are typically associated with shoals, drop offs, or in aquatic vegetation near shore (Foust and Haynes 2007), while in some lakes and reservoirs walleye make more use of pelagic waters (Ager 1976; Festa 1987; Palmer 2005, Byrne et al. 2009). Walleye have been stocked at a target rate of 80,000/year from 2000-2006 and 40,000/year since 2007. Here, walleye occupy rocky shoals, weedy littoral areas and epilimnetic pelagic waters, rarely occurring at depths below 15m (Stich et al. 2008, Byrne et al. 2009, Potter et al. 2010). Alewife (Alosa pseudoharengus) were first documented in Otsego Lake in 1986 (Foster 1990) and were dominant by the early 1990s (Harman et al. 2002). They are efficient epilimnetic planktivores that demonstrate diel patterns in vertical migration and schooling behavior (Appenzeller and Legget 1992; Luecke and Wurtsbaugh 1993). Habitat utilizations during summer stratification indicate spatial overlap between walleye and alewife.