THE STATUS OF WALLEYE IN LAKE ONTARIO, 1988-2006

• Published in: Technical report (Great Lakes Fishery Commission) Vol. 69; no. 69; pp. 165 - 188
• Main Authors: Bowlby, J N, Hoyle, JA, Lantry, J R, Morrison, B J
• Format: Journal Article
• Language: English
• Published: 01.03.2010
• Subjects: Alosa pseudoharengus; Marine; Neogobius melanostomus; North America, Ontario L
• ISSN: 0072-730X

Following a resurgence that began in the late 1970s and that continued through the early 1990s, the abundance of walleye (Sander vitreus) in eastern Lake Ontario, including the Bay of Quinte, declined sharply. This decline was associated with a 75% drop in the abundance of young-of-the-year walleye that occurred after establishment of dreissenids. Potential hypotheses explaining the decline in walleye abundance include decreased suitable spawning habitat, increased levels of predation and/or competition linked to dreissenid-induced clearing of the water column, or reduced food supply/availability linked to dreissenid-induced increases in macrophytes. Despite the decline in abundance, the walleye population in eastern Lake Ontario retains a broad age structure and supports an angling fishery with harvest rates close to 0.2 fish per angler-hour. Beginning in about 2000, walleye growth increased by about 10% while age at maturity of both male and female walleye declined by about one year. The summer diet of walleye in the Bay of Quinte has shifted from one dominated by alewife (Alosa pseudoharengus) to one, including a greater diversity of fishes, including the round goby (Neogobius melanostomus), a recent invader.