Biology and Status of Bull Trout (Salvelinus confluentus) in the Kakwa River Drainage, Alberta


Paul Hvenegaard and David Fairless


Data on bull trout population biology and status in the Kakwa River were collected from July 1995 to November 1997. In total, 1087 bull trout were sampled during the study; the mean fork length was 333 mm with a range of 45 – 731 mm. Fish enumeration traps/fences were placed in Lynx, Copton, Chicken, Daniel, and Prairie creeks. Bull trout captures varied from a high of 77 at Lynx Creek in 1995 to a low of 3 at Daniel creek in 1995. Timing of spawning movements were gauged using radio telemetry and trap catch data. Bull trout from the Kakwa River drainage appear to enter their spawning tributaries earlier and remain longer than reported by other researchers. Specific bull trout spawning sites were identified in Lynx, Copton, and Prairie creeks using radio telemetry data. Presence of young-of-the-year bull trout in, Redrock, Little Redrock, and Route creeks also identified generalised spawning locations. Mainstem abundance of bull trout from late fall surveys was estimated at 7.3 bull trout per kilometre. This estimate occurred in a 32-kilometer section of the upper Kakwa River and will serve as a river monitoring index site for future measurements of bull trout management strategies. Estimates of juvenile bull trout densities at four (400 – 600 m) sites in Lynx Creek ranged from (4 – 75) bull trout per site. Increase in bull trout fork length was slight, 28 mm over a mean of 479 days between measuring events.


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