Summary of Summer Sport Fishery & Special Harvest License for Walleye at Iosegun & Smoke Lakes, Alberta, 2013
Author(s)
William Patterson, Troy Furukawa, and Melissa Buskas
Summary
Walleye (Sander vitreus) populations throughout Alberta experience high angling pressure and are characterized by late‐maturity and slow growth rates. This has resulted in many populations being susceptible to overharvest and consequent declines in numbers and size. As a recovery strategy, minimum‐size regulations were implemented that required anglers to release the majority of their catch. This strategy resulted in increases in walleye recruitment and exploited adults, but walleye were not growing large in size, regardless of their age. To restore walleye populations to a balance between size, growth and maturity, the sport fishing regulations at Iosegun and Smoke lakes were changed to a limited harvest of walleye <50 cm total length (TL). Anglers wanting to harvest walleye from Iosegun or Smoke lakes must apply for a Special Walleye Licence (SWL; a draw and tag system) for a specific size category; either <43 cm TL or 43 – 50 cm TL. The overall goal of this project is to evaluate the effectiveness of this regulation change designed to promote larger‐sized walleye in certain populations. In year two of this two‐year study, we continued to monitor the sport fishery by conducting a creel survey during the summer of 2013. Data were collected on angling effort, catch rates, population structure and other related sport fishery demographics.
We interviewed 215 anglers at Iosegun Lake, with a total angling effort and pressure of 3,203 h (95% CI = 1,965 – 4,672) or 2.4 h/ha (95% CI = 1.5 – 3.5), respectively. The total catch rate for walleye was 1.6 fish/h, and the release rate was 1.5 fish/h. We estimated 309 walleye (95% CI = 76 – 626) were harvested and the yield (harvest + release mortality) was 396 kg (95% CI = 191 – 650) or 0.3 kg/ha (95% CI = 0.14 – 0.49). The length distribution of test‐angled walleye ranged from 292 to 495 mm TL, with a mean (± SE) length of 411 ± 2 mm TL (n = 374). Length of sport‐harvested walleye ranged from 415 to 472 mm TL, with a mean of 444 ± 3 mm TL (n = 32). Age of test‐angled walleye ranged from 3 to 14 y, with a mean of 7.4 ± 0.2 y (n = 163), while age of sport‐harvested walleye ranged from 7 to 14 y, with a mean of 9.0 ± 0.3 y (n = 32). Walleye grew quickly to approximately 400 mm TL, with no fish growing longer than 500 mm TL. All walleye sampled in the sport harvest were mature.
Of the 215 anglers interviewed at Iosegun Lake, 118 had not fished the lake the previous year. Of the 206 anglers surveyed regarding SWLs, only 38 held a SWL of which 22 and 16, respectively, held a SWL to harvest three walleye <43 cm TL and 43 – 50 cm TL. Of the 32 walleye observed harvested, 100% were in the correct SWL size class.
We interviewed 246 anglers at Smoke Lake, with a total angling effort and pressure of 1,545 h (95% CI = 1,195 – 1,937) or 3.8 h/ha (95% CI = 2.8 – 4.8), respectively. The total catch rate for walleye was 2.4 fish/h, and the release rate was 2.3 fish/h. We estimated 241 walleye (95% CI = 113 – 397) were harvested and the yield (harvest + release mortality) was 174 kg (95% CI = 123 – 378) or 0.18 kg/ha (95% CI = 0.13 – 0.39). The length distribution of test‐angled walleye ranged from 234 to 566 mm TL, with a mean (± SE) length of 411 ± 2 mm TL (n = 377). Length of sport‐harvested walleye ranged from 387 to 490 mm TL, with a mean of 440 ± 4 mm TL (n = 44). Age of test‐angled walleye ranged from 3 to 15 y, with a mean of 7.2 ± 0.2 y (n = 165), while age of sport‐harvested walleye ranged from 6 to 14 y, with a mean of 9.5 ± 0.5 y (n = 29). Walleye grew moderately quick to approximately 400 mm TL, with growth slowing and the majority of fish not growing longer than 500 mm TL. Of the harvested walleye, 50% of female walleye were mature by age 9 (n = 9); the majority (93%, n = 15) of male walleye were mature.
Of the 246 anglers interviewed at Smoke Lake, 121 had not fished the lake the previous year. Of the 233 anglers surveyed regarding SWLs, 183 held a SWL of which 31 and 19, respectively, held a SWL to harvest three walleye <43 cm TL and 43 – 50 cm TL. Of the 44 walleye observed harvested, four were the wrong size for the corresponding tag. Two walleye were observed harvested by an angler who did not hold a SWL.