Aerated Lakes Angler Survey: Swan and Spring Lakes, Alberta, 2015


Nikita Lebedynski


In Alberta, stocking waterbodies that lack sport fish provides additional angling opportunities in a province with few fish-bearing lakes and high numbers of anglers. Alberta Environment and Parks and Alberta Conservation Association (ACA) stick, aerate and maintain user facilities at many waterbodies throughout Alberta. To prevent winterkill of stocked trout, ACA uses various aeration techniques to enhance winter dissolved oxygen levels at 16 waterbodies across the province. The increased dissolved oxygen levels result in year-round survival of stocked fish and the creation of sport fisheries capable of producing large trout. In the summer of 2015, we conducted angler
surveys to assess angling pressure, catch and harvest at two popular aerated lakes in northwest Alberta: Swan and Spring lakes. Both lakes are stocked annually, have a daily bag limit of five fish of any size and are open for angling year round.

At Swan Lake, 341 anglers were interviewed, and fishing pressure was estimated to be 31.5 h/ha (95% CI = 28.3 – 35.1) during the survey period. Catch-per-unit-effort (CPUE) was 0.159 rainbow trout per hour. Total yield of rainbow trout was 322.6 kg (95% CI = 289.7 – 358.8) or 1.98 kg/ha (95% CI = 1.78 – 2.21). Fish ranged in size from 205 to 585 mm total length (TL) (n = 38).

At Spring Lake, 592 anglers were interviewed, and fishing pressure was estimated to be 224.4 h/ha (95% CI = 206.0 – 244.4) during the survey period. Total CPUE was 0.501 fish/h and was 0.47 fish/h and 0.03 fish/h for rainbow and brook trout, respectively. Total yield of rainbow trout was 650.2 kg (95% CI = 596.9 – 708.3) or 16.2 kg/ha (95% CI = 14.9 – 17.7). Total yield of brook trout was 54.7 kg (95% CI = 50.2 – 59.6) or 1.36 kg/ha (95% CI = 1.25 – 1.49). Rainbow trout ranged in size from 208 to 536 mm TL (n = 141). Brook trout ranged in size from 314 to 428 mm TL (n = 15).

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