Summer Sport Fishery for Lake Trout, Walleye and Northern Pike at Cold Lake, Alberta, 2005
The Alberta Conservation Association (ACA) conducted a creel survey at Cold Lake during the 2005 summer fishing season to provide information on angler use, sport fish yield and population structure. The survey focused primarily on the lake trout sport fishery although data on the walleye and pike sport fisheries were also collected. Access point surveys were conducted from two sites, the Cold Lake Marina (hereafter CLM) and the Cold Lake Provincial Park (hereafter PP) from 21 May to 21 August 2005.
During the survey period, approximately 69% of the angling effort was from CLM and PP combined. The remaining 31% was by anglers who used access points not surveyed (e.g., provincial parks, boat launches). An estimated 9,088 anglers (95% CI = 7,839 - 10,393, n = 1,940) fished the lake for 31,525 h (95% CI = 27,112 - 36,236, n = 6,933) or 0.90 h/ha (95% CI = 0.78 - 1.04).
At the survey sites recreational anglers were the majority (i.e., CLM = 83%, n = 1,060; PP = 99%, n = 880). Anglers utilizing the guiding services available on Cold Lake represented 17% and 1% of the CLM and PP anglers, respectively.
An estimated 1,098 lake trout (95% CI = 853 - 1,371, n = 244) were harvested by anglers during the survey period of which 68% were harvested by recreational anglers while guided anglers harvested 32%. Simulations using three scenarios of incidental mortality (i.e., low 5%, moderate 10%, and high 15%) suggest additional 174 - 521 fish, respectively could potentially die from incidental mortality.
An estimated 3,473 lake trout (95% CI = 2,829 - 4,174, n = 858) were reported released by anglers, of which 75% were by recreational anglers and 25% by guided anglers. Generally, the length of the harvested lake trout ranged 352 - 803 mm (fork length) and weight ranged 2,350 - 7,500 kg. Mean weight of a trout harvested by either group was 4,443 g (95% CI = 4,427 - 4,642, n = 161) with estimated yield of 0.140 kg/ha (95% CI = 0.139 - 0.144). The total catch rate for lake trout was 0.162 fish/h. Guided anglers had a higher total catch rate (harvest + released fish) than the recreational anglers i.e., 0.427 fish/h versus 0.130 fish/h. Harvest and release rates were 0.036 fish/h and 0.126 fish/h, respectively. Of the 165 observed harvest, 8 were protected-length fish. Reported release rates for protected-length and legal-length lake trout were 0.089 fish/h and 0.037 fish/h, respectively. All lake trout captured were mature.
An estimated 30 walleye (95% CI = 84 - 526, n = 26) were harvested by anglers during the survey period. All walleye were harvested by recreational anglers; guided anglers did not capture any walleye. Estimated mean weight of harvested walleye was 2,328 g/fish (95% CI = 2,175 - 2,519, n = 18) and yield was 0.015 kg/ha (95% CI = 0.006 - 0.035). Anglers released 745 walleye (95% CI = 347 - 1,532, n = 101). The incidental mortality of walleye was an additional 41 fish (95% CI = 18 - 73). Overall, the catch rate for walleye was very low. The exaggeration of catch rates may indicate that fishing success is much poorer than reported.
An estimated 554 pike (95% CI = 409 - 697, n = 124) were harvested by anglers during the survey period. Similar to walleye, all pike were harvested by recreational anglers; guided anglers did not capture any. Estimated mean weight of harvested pike was 2,224 g/fish (95% CI = 1,997 - 2,425, n = 55) and yield was 0.036 kg/ha (95% CI = 0.030 - 0.038). Anglers released 7,855 pike (95% CI = 6,458 - 9,369, n = 1,530). Based on data collected from the test angling, pike released had a mean weight of 0.909 kg/fish (95% CI = 0.861 - 0.946, n = 110); estimated additional yield due to incidental mortality was 0.011 kg/ha (95% CI = 0.009 - 0.013). Age-class distribution for pike (both recreational harvest and test angling) was moderately broad with low densities. The catch rate was low for legal-size pike and moderate for protected-length fish. Pike were growing to the legal-size limit in five years. No large fish (>70 cm TL) were caught. Sport anglers had very poor success and a small portion of anglers harvested the majority of fish.