Status of Walleye and Northern Pike Sport Fisheries at Long Lake, Alberta, 2004
Greg Fortier and John Tchir
Increased access in the Red Earth area in northern Alberta has raised concerns about impacts of potential increases in angling pressure on sport fish populations of lakes in the region, including Long Lake. The present study was conducted on Long Lake to generate quantitative data on angler use and catch rates, as well as population structure and growth, of two sport fish species, walleye (Sander vitreus) and northern pike (Esox lucius). The information collected in this survey can be used to assess impacts of increased fishing pressure after increases in access.
An estimated 56 (95% CI = 29 - 92) anglers fished at Long Lake from 29 May to 22 August 2004, resulting in an angling pressure of 0.310 angler-h/ha (95% CI = 0.165 - 0.549). The overall catch rate (expressed as total catch-per-unit-effort) of walleye was 0.47 fish/h. No harvest of walleye was reported. In contrast, the overall catch rate of northern pike was 0.12 fish/h, with a total harvest-per-unit-effort of 0.018 fish/h. The total estimated harvest of northern pike was 0.046 kg/ha (95% CI = 0.0 - 0.101 kg/ha).
Length of walleye caught during test angling ranged from 227 to 563 mm with a mean (± SD) of 433.9 ± 77.0 mm (n = 21), ages ranged from 3 to 15 y with a mean of 7.2 ± 2.8 y (n = 21). In contrast, length of northern pike caught during the test angling ranged from 294 to 775 mm with a mean of 516.6 ± 110.6 mm (n = 87) and ages ranged from 1 to 10 y with a mean of 4.3 ± 2.0 y (n = 82). Based on von Bertalanffy growth estimates, walleye in Long Lake should reach harvestable size (> 50 cm TL) in 12 to 13 years. Northern pike may not reach harvestable size (> 70 cm TL) based on the growth parameters.
Results of our study will aid fisheries managers in formulating management guidelines for walleye and northern pike sport fisheries for priority lakes in the Red Earth area. Although our estimated angling pressures at Long Lake may be considered low, improved access and upgrading of facilities at the lake may result in increased fishing pressure in the future. Our data will serve as the baseline for assessing future impacts.