Sport Fish Distribution and Relative Abundance on the Lower Red Deer River from Dickson Dam to Joffre, Alberta, 2005


Jason Blackburn


Sport fish relative abundance and distribution data were collected on a 97-km reach of the Lower Red Deer River from Dickson Dam to the Highway 11 Bridge near Joffre. A total of 50 1-km sample sites were boat electrofished at 2-km intervals. A concurrent mark-recapture population estimate was also attempted on five consecutive river kilometres immediately downstream of Dickson Dam. The mark-recapture component was not completed because of high river flows and resulted in no viable estimate from two passes and a single recapture. Excluding the first pass of the population estimate, a total of 3,105 fish were captured or enumerated across 50 sample sites. A total of 15 species were identified, of which ten were sport fish species. Mountain whitefish was the most abundant species representing 53.9% of the total sample and occurred at 33.5 fish/km, followed by goldeye at 18.7% and 11.6 fish/km. Walleye were the next most abundant sport species at 2.9% of the total and 1.8 fish/km, followed by brown trout at 1.4% and 1.2 fish/km. The remaining sport species, including mooneye, burbot, northern pike, lake whitefish, rainbow trout and sauger, each represented less than 1% of the total sample and occurred at less than 1 fish/km. The most abundant species were also the most widely distributed throughout the study area. In comparison with 1991 data, goldeye showed the greatest increase in overall abundance from 1.0 to 11.6 fish/km followed by an increase in walleye from 0.7 to 1.8 fish/km. The remaining sport species decreased in overall abundance. Most notably, brown trout decreased from 2.6 to 0.9 fish/km, northern pike from 1.4 to 0.2 fish/km and lake whitefish from 1.4 to 0.1 fish/km. Species that increased in abundance also increased in distribution, and species that decreased in abundance showed reductions in distribution throughout the study area; with the exception of lake whitefish which decreased in abundance but remained in three of six reaches in both 1991 and 2005.

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