Movements of Walleyes in Claytor Lake and the Upper New River, Virginia, Indicate Distinct Lake and River Populations
ABSTRACT Inference that more than one genetic stock of walleyes Sander vitreus was present in Claytor Lake, Virginia, and its main influent, the New River, raised questions concerning the spawning movements, locations of spawning grounds, and home range of resident stocks. We conducted a radiotelemetry study of 52 walleyes in Claytor Lake and the upper New River over a period of 2 years. Our findings support the hypothesis that two populations coexist within the system, exhibiting different home ranges, spawning movements, and spawning grounds, even though there is no physical barrier to movement between the spatially disjunct populations. Walleyes living within Claytor Lake mostly spawn at the first riffle area above the reservoir, whereas those living in the New River mostly spawn at two riffle areas well upstream. Coexistence of distinct populations in the system justifies different management strategies. Management of the walleye population in Claytor Lake should focus on increasing the exploitation of the nonindigenous lake stock. Management of the upper New River walleye population should focus on conservation of the unique river stock through supportive breeding, strict harvest regulations, or both.
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ABSTRACT: A Denil fishway in Dunnville, Ontario was built to provide upstream passage for walleyes (Stizostedion vitreum) from Lake Erie to the Grand River. Few walleyes have been observed to use this fishway. Coded radiotelemetry was used to track 24 adult walleyes (12 male, 12 female) downstream from the fishway to explore reasons for limited use. Activity was monitored by a fixed array of three antennas within the fishway that continuously scanned for signals from all radio-tagged fish, and by mobile tracking. In April and May 1997, 17 attempts to use the fishway by 3 male and 2 female radiotagged walleyes were recorded. During this period, the attraction efficiency of the Dunnville Fishway was approximately 21%. All attempts took place between 1600 and 0600 hours, with most activity near midnight. Walleyes occupied the first resting pool of the fishway for up to 17 h. Subsurface water velocity during the study was approximately 2 m/s. No radio-tagged walleyes passed through the Dunnville Fishway. Behavior modifying hydraulic conditions including turbulence, entrained air, backcurrents and whirlpools in fishway resting areas may delay or prevent successful upstream passage of walleyes. There was also evidence of large-scale movements by walleyes that may have spawned in the Grand River downstream from Dunnville.Journal of Great Lakes Research. 01/2000;
- Fisheries 08/1993; 18:11-21. · 2.88 Impact Factor
- 7 01/1999; John Wiley & Son.