Assessment of Summer Sport Fishery for Walleye and Northern Pike at Orloff Lake, Alberta, 2004
To maintain and recover Alberta's walleye and pike fisheries, Alberta Sustainable Resource Development (ASRD) developed and implemented new management strategies in 1996 for walleye and in 1999 for northern pike (hereafter pike). Orloff Lake, located north of Athabasca, Alberta, was classified as having a vulnerable walleye fishery between 1996 and 2004 (Alberta Guide to Sportfishing Regulations 1996 and 2004). This classification resulted in the implementation of a regulation that allowed anglers to harvest three walleye (daily maximum bag limit) with a minimum size limit of 50 cm total length (TL). From 1999 to 2004, the pike fishery was classified as a stablerecreational fishery, allowing sport anglers to harvest three pike (daily maximum bag limit) with a minimum size limit of 63 cm TL.
Alberta Conservation Association (ACA) creel surveys are conducted in support of the management of Alberta’s sport fisheries. Creel surveys provide the field data that are used by ASRD to manage sport fisheries and support management strategies. ASRD walleye and pike management strategies are based on estimates of how harvest pressure can alter the impact of management decisions (Berry 1995). Since the inception of ASRD’s walleye and pike management strategies, the sport fishery at Orloff Lake has not been assessed by neither ASRD nor ACA. Anecdotally, the lake was reportedly receiving increased angling pressure over historic levels. Hence, ASRD requested that ACA conduct a creel survey during the summer of 2004 to provide an estimate of angler effort and stock yields for walleye and pike. Based on angler interviews conducted between 23 May and 16 August 2004, an estimated 488 anglers (95% CI = 361 - 663, n = 202) fished Orloff Lake for 1,749 h (95% CI = 1,285 - 2,404, n = 684) for an angling pressure of 0.95 angler-hrs/ha (95% CI = 0.70 - 1.31).
Estimated angler harvest of walleye was 286 fish (95% CI = 186 - 429, n = 120), which had an estimated mean weight of 1.544 kg (95% CI = 1.419 - 1.676 kg) per fish. This produced an estimated yield of 0.24 kg/ha (95% CI = 0.16 - 0.37). Anglers released an estimated 697 walleye (95% CI = 451 - 1,085, n = 257), for an estimated total yield (harvest + hooking mortality) of 0.25 kg/ha (95% CI = 0.220 - 0.399).
Estimated angler harvest of pike was 106 fish (95% CI = 67 - 170, n = 40), with a mean weight of 1.980 kg (95% CI = 1.772 - 2.223 kg) per fish. This produced an estimated yield of 0.12 kg/ha (95% CI = 0.07 - 0.18). Anglers reported a pike release rate of 0.367 fish/h, which translates to an estimated catch and release of 1,293 pike (95% CI = 1,022 - 1,667, n = 322). The estimated total yield of pike was 0.15 kg/ha (95% CI = 0.11 - 0.22).