Movements of Walleyes in Claytor Lake and the Upper New River, Virginia, Indicate Distinct Lake and River Populations

Virginia Polytechnic Institute and State University, Блэксбург, Virginia, United States
North American Journal of Fisheries Management (Impact Factor: 1.11). 11/2005; 25(4):1448-1455. DOI: 10.1577/M05-019.1

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.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Walleye (Sander vitreus) are the main contributor to Manitoba's multi-million dollar commercial fishery, with Lake Winnipeg providing the largest and most profitable catch. In some systems, walleye show evidence of returning to the same spawning site each spring (i.e., philopatry), which can lead to the existence of multiple genetically-discrete spawning groups (i.e., stocks) within a lake. This study used nine microsatellite loci (N=932) and one mitochondrial restriction fragment length polymorphism assay (N=123) to investigate possible genetic divergence among walleye from 13 spawning sites in Lake Winnipeg, and compared these with those collected from two hatchery locations and other locations outside of Lake Winnipeg. Microsatellite loci resolved little population structure within Lake Winnipeg, with the exception of two sites (Grand Rapids and the Icelandic River), which showed low but significant levels of genetic divergence with most other sites (F-st=0.0066-0.0457). Slight to moderate genetic divergence was found between Lake Winnipeg walleye and sampling locations outside of Lake Winnipeg (F-st=0.0037-0.1054, P=0.0002). Mitochondrial DNA analysis indicated colonization of Lake Winnipeg by walleye from two glacial refugia (Missourian and Mississippian), but no population structure was detected among sites. The lack of stock structure found in Lake Winnipeg possibly indicates a low degree of natal philopatry, an amount of straying sufficient to obscure genetic structure, or obscured structure as a result of historical and current stocking. Overall genetic variation, using both mitochondrial and microsatellite markers, appeared comparable to that found in other walleye populations.
    Journal of Great Lakes Research 01/2012; 38:47-57. DOI:10.1016/j.jglr.2011.05.005 · 1.77 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Habitat utilization and movements of walleyes in Otsego Lake were studied from April through November 2006 using acoustical tags. Tagged walleye were primarily found in the shallow, weedy areas at the north end of Otsego Lake in less than 20 feet of water. On average males were found closer to shore (mean distance from shore 416 feet) than females (793 feet from shore). Two fish were relatively sedentary following spawning, while two fish were more nomadic. Walleye habitat utilization and movement patterns in Otsego Lake differed from that observed in shallow, warm-water lakes and reservoirs.
  • Source