24 Mar What Happened to West Arm Burbot Stock in Kootenay Lake?
Use of an Age-Structured Population Model to Determine the Possible Causes for Recruitment Failure
The West Arm of Kootenay Lake once supported a significant burbot (Lota Iota) fishery with an annual harvest of up to 20,000 fish in the late 1960’s to early 1970’s. Catches declined precipitously beginning in the mid-1970’s and by the mid-1980’s catches were typically less than 400 fish. The fishery was eventually closed to angling in 1997 (Andursak 1998). As a consequence of the low numbers of burbot in Kootenay Lake and the Kootenai River, fisheries agencies in B.C. and Idaho initiated activities to review the status of this species in the Kootenay drainage and identify recovery options. With regards to the West Arm burbot stock, two questions remain: 1) What were the principal factors that caused the stock to decline? and 2) What are the most feasible options for rebuilding the stock? A team of biologist led by the Ministry of Water, Land and Air Protection initiated a modeling exercise to address these questions. Results from the exercise were presented and discussed at a workshop held in Nelson B.C. on Dec. 5-6, 2001. This report summarizes the modeling results and workshop discussions.