Status of Walleye and Northern Pike Sport Fisheries at Gods Lake, Alberta, 2004
Greg Fortier and John Tchir
Improved access to lakes in the Red Earth area in northern Alberta has raised concerns about impacts of potential increases in angling pressure on the relatively unexploited sport fish populations of these lakes. However, very little quantitative data exist on angling pressure and sport fish harvest on most of these lakes, including Gods Lake. To generate such data on Gods Lake, a creel survey was conducted on the lake during the summer of 2004.
An estimated 990 (95% CI = 780 - 1240) anglers fished at Gods Lake from 21 May to 29 August 2004, resulting in an angling pressure of 2.31 angler-h/ha (95% CI = 1.80 - 2.86). The overall catch rate (expressed as total catch-per-unit-effort, TCUE) of walleye (Sander vitreus) was 0.32 fish/h and the total harvest-per-unit-effort (THUE) was 0.07 fish/h. The total estimated walleye harvest was 0.33 kg/ha (95% CI = 0.27 - 0.41 kg/ha). In contrast, the overall TCUE of northern pike (Esox lucius) was 0.91 fish/h, with an estimated THUE of 0.003 fish/h.
Length of walleye harvested by anglers ranged from 492 to 688 mm with a mean (± SD) of 541.8 ± 39.1 mm (n = 41) and ages ranged from 7 to 22 y with a mean of 10.1 ± 3.5 y (n = 41). Length of fish caught during test angling ranged from 413 to 650 mm with a mean of 491.9 ± 47.7 mm (n = 33) and ages ranged from 5 to 21 y with a mean of 8.0 ± 2.8 y (n = 30).
Only one of two northern pike harvested by anglers was sampled by creel clerks. This fish measured 1000 mm at an age of 10 y. Length of northern pike caught during test angling ranged from 312 to 912 mm with a mean of 604.8 ± 95.9 mm (n = 77) and ages ranged from 2 to 12 y with a mean of 5.9 ± 1.4 y (n = 80).
Based on von Bertalanffy growth estimates, walleye in Gods Lake should reach harvestable size (> 50 cm TL) in 7.4 years; limited data precludes similar estimates for northern pike.
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 pressure at Gods 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.