Abundance and Population Structure of Walleye in Pigeon and Buck Lakes Summary
Author(s)
Shane Wood and Clayton James
Summary
Walleye (Sander vitreus) populations throughout Alberta are faced with high angling pressure, late-maturity, and slow-growth rates, resulting in many populations being susceptible to over-exploitation. In 1995, Alberta Sustainable Resource Development (ASRD) implemented the Alberta Walleye Management and Recovery Plan (AWMRP) to facilitate the protection and recovery of exploited walleye fisheries. As part of the AWMRP, the Alberta Conservation Association (ACA) conducted gill net surveys in Pigeon and Buck Lakes from 27 September to 1 October 2010 to examine population
structure and growth characteristics of walleye.
Relative abundance of walleye in Pigeon Lake was 29.0 fish/100 m2/24 h (95% CI = 21.9 – 38.6, n = 7). Size of walleye ranged from 190 to 523 mm FL, with the majority of the population in the 400 to 500 mm FL size ranges. Fish age ranged from 1 to 13 y, with the population composed mainly of the 12 y age-class, which comprised 41% of the total catch. Based on the AWMRP criteria, the walleye population in Pigeon Lake exhibits a wide (>8 age-classes) and very stable (mean age >9 y) age-class distribution. Overall, growth rates were slow with the average fish hardly attaining the 500 mm FL AWMRP standard size. Males grew slower than females with estimated average maximum sizes (L∞) of 432 and 472 mm FL, respectively. Walleye in Pigeon Lake mature early, with males reaching maturity at age 4 and females at age 5.
Relative abundance of walleye in Buck Lake was 27.6 fish/100 m2/24 h (95% CI = 23.6 – 32.0, n = 9). Size of walleye ranged from 165 to 492 mm FL, with the majority of the population (89%) in the 300 to 450 mm FL size ranges. Fish age ranged from 1 to 16 y, with the population composed mainly of 4 y and 5 y age-classes, which comprised 49% of the total catch. Based on the AWMRP criteria, the walleye population in Buck Lake exhibits a wide (>8 age-classes) and stable (mean age 6 - 9 y) age-class distribution. Similar to Pigeon Lake, growth rates were slow with the average fish hardly attaining the 500 mm FL AWMRP standard size. Males grew slower than females with estimated
average maximum sizes (L∞) of 437 and 485 mm FL, respectively. Walleye from Buck Lake mature early, with males reaching maturity by age 5 and females by age 6. The information collected in these surveys will provide current data to ASRD, assisting managers in making accurate management decisions regarding the sport fishery and sustainability of walleye populations within these lakes.