A Sport Fish Stock Assessment of Long Lake, Alberta, 2004
Greg Fortier and John Tchir
In recent years, improved access to lakes that support populations of walleye (Sander vitreus) and northern pike (Esox lucius) has raised concerns about increased angling pressure on relatively unexploited fish populations. Strategies to maintain or recover northern pike and walleye populations, implemented by Alberta Sustainable Resource Development include changes in angling regulations to reduce fish mortality and increase recruitment. Regular evaluations of the abundance and structure of sport fish populations are necessary to evaluate the effectiveness of management strategies.
We completed a stock assessment to quantify the size, age structure and growth of walleye, northern pike, lake whitefish (Coregonus clupeaformis) and yellow perch (Perca flavescens) in Long Lake, Alberta. Walleye accounted for 18.3% of the total catch. The total catch per unit effort (TCUE) of walleye was 6.65 fish/100 m2/24 hrs. Of all walleye sampled where sex could be determined, 43.7% were female. Fork lengths (FL) of walleye ranged from 214 to 529 mm (mean = 430.8 mm, n = 12) and age ranged from 3 to 18 years (mean = 9.6, n = 107). In contrast, northern pike accounted for 32.7% of the total catch with a TCUE of 11.81 fish/100 m2/24 hrs. Of all northern pike sampled where sex could be determined, 51.8% were female. Fork lengths of northern pike ranged from 223 to 889 mm (mean = 507.0 mm, n = 199), and age ranged from 1 to 15 years (mean = 6.4, n = 176). Lake whitefish accounted for 3.1% of the total catch with a TCUE of 1.13 fish/100 m2/24 hrs. Of all lake whitefish sampled where sex could be determined, 47.4% were female. Fork lengths of lake whitefish ranged from 314 to 531 mm (mean = 410.8 mm, n = 19) and age from 4 to 13 years (mean = 6.0, n = 18). Yellow perch accounted for 18.1% of the total catch with a TCUE of 6.53 fish/100 m2/24 hrs. Of all yellow perch sampled where sex could be determined, 67.9% were female. Fork length of yellow perch ranged from 121 to 247 mm (n = 110, mean = 161.7 mm) and ages from 3 to 11 years (mean = 4.3, n = 106).
The stock assessment presented here allows fisheries managers to track potential effects of increased angling pressure on priority fish populations, like Long Lake, in the future. Increased monitoring of fish populations at Long Lake and other lakes in the Red Earth area will become more important with the development of the proposed highway extending from Red Earth to Fort McMurray.