Survey of lake trout and arctic char in Walker Lake, Gates of the Arctic National Park and Preserve, 1987-1989
Johnson RR and Troyer KD. 1994. Survey of lake trout and arctic char in Walker Lake, Gates of the Arctic National Park and Preserve, 1987-1989. Alaska Fisheries Technical Report. 25. US Fish and Wildlife Service, Department of the Interior Region 7. Fairbanks, AK
Fish populations were sampled at Walker Lake within the Gates of the Arctic National Park and Preserve during the spring and summer of 1987 and 1988. Populations were sampled using creel surveys to determine effect of sport fishing on lake trout Salvelinus namayusch and Arctic char S. alpinus, and gill nets were deployed in nearshore areas to mark and recapture fish for population estimates, determine abundance in different habitats, and obtain biological samples for age, growth, weight-length, fecundity, maturity, and food habit determination.. Physical and chemical properties of the lake were also recorded. Harvests were determined to be within the levels considered sustainable for arctic and subarctic lakes. Lake trout abundance appeared to increase near stream mouths, while Arctic char abundance decreased over cobble/boulder substrates from early to late season. Weight-length regression coefficients indicated healthy growth, with growth rates of lake trout after age 5 appearing to be greater than other northern and central Alaska populations and Arctic char growth rate appearing to be greater than several other populations in northern Alaska. Lake trout appeared to be primarily piscivorous, while Arctic char were primarily nonpiscivorous. Fecundity was withing the range documented for other populations in northern Alaska for both species. Management options are discussed, although harvest levels were low relative to population size and ther was no evidence of overexploitation.
- Type
- Published Report
- Authors
- Johnson, Richard; Troyer, Kenneth
- Date of Issue
- 1994
- Publisher
- US Fish and Wildlife Service, Department of the Interior Region 7
- Units
- GAAR
- Keywords
- Animal Studies, Aquatic Sciences, Arctic Char, Creel Survey, Fecundity, Fish, Food Habits, Freshwater, Gates of the Arctic National Park and Preserve AK, Habitat, Lake Trout, management options, Population Estimate