Angler Survey and Walleye Abundance in Fawcett Lake, Alberta 2003
Greg Fortier, John Tchir, and Lorraine Sawdon
Walleye (Sander vitreus) populations in Alberta experience considerable fishing pressure that has resulted in the overexploitation of most populations. To aid in their recovery Alberta Sustainable Resource Development (ASRD) initiated a province-wide management strategy, the Alberta Walleye Management Recovery Plan (WMRP), in 1995. The current study was conducted to assess the status of the walleye fishery in Fawcett Lake as part of the province-wide walleye recovery program. Although Fawcett Lake is popular among recreational fishermen, limited data exist on the fish populations or fishing pressure on the lake. The main objectives of our study were to 1) estimate the population size and structure of walleye in the lake, and 2) estimate angling pressure on the walleye population. A mark-recapture study was used to estimate the walleye population size while an access-based creel survey was used to estimate angling pressure, total catch and harvest, and biological characteristics of walleye.
Total length (TL) of walleye, from trap-netting and angling, ranged from 209 to 744 mm. Of the 5814 fish captured in traps 4103 were males and 1711 were females, resulting in a sex ratio of 2.4 males to 1.0 female. Mean (±SD) size of marked fish was 407.2 ± 34.8 mm TL (n = 4103) for males and 449.7 ± 41.9 mm TL (n = 1711) for females. Mean TL of angler-harvested fish was 457.3 ± 31.8 mm (n = 17), 7.9% of which were of sub-legal size (TL < 430 mm). Overall, age of walleye ranged from 4 to 18 y but the population was dominated by ages-5 to 13 fish. Mean age of angler-harvested fish was 9.9 ± 2.01 y (n = 243).
Based on maximum likelihood estimates (MLE), the population of walleye > 300 mm TL was 64,020 (95% CI = 49,020 – 96,390) with an associated density of 18.7 fish/ha (95% CI = 14.4 – 28.2). Maximum likelihood estimates from the creel survey indicated that anglers exerted a fishing pressure of 23,325 angler-h (95% CI = 22,400 – 30,575) or 7.4 h/ha (95% CI = 6.6 – 9.0) from 16 May to 1 September 2003. The mean daily catchper- unit-effort (CPUE, #fish/angler-h) for walleye was 0.873 (95% CI = 0.689 – 1.057) while the harvest-per-unit-effort (HPUE, #fish kept/angler-h) was 0.066 (95% CI = 0.046 – 0.087). An estimated 22,800 walleye were caught (95% CI = 19,425 – 27,825) and 1,710 harvested (95% CI = 1,390 – 2,150).
Majority (75.4%) of the 2061 anglers surveyed targeted walleye and used baits (77.3%), barbed hooks (83.6%) and depth sounders (54.9%). Most of the anglers (84.6%) that visited Fawcett Lake resided in Edmonton and surrounding area.