| Abstract/Description or Keywords |
In Canada, the Speckled Dace population is limited to one watershed (Kettle River) and the species is found in three locations within that drainage. Hundreds of populations exist in the western United States. However, the Kettle River population is unique in Canada. The Canadian distribution of Speckled Dace is peripheral and disjunct because the population is located above a barrier (Cascade Falls), and is at the extreme northern extent of their North American range. Rescue from downstream systems is not possible. The known range of the population has increased slightly since the COSEWIC (2006) assessment. This is likely due to increased survey effort and not due to an actual range extension by dace. Speckled Dace appear to be distributed widely and somewhat evenly throughout their approximately 300km Canadian range. Their use of habitat extends from the river margins (as juveniles) to the main channel (as adults). There appears to be abundant, suitable, and widely distributed habitat for the species. The Kettle River Speckled Dace population was estimated at over 900,000 mature dace, but this single estimate is insufficient to draw any conclusions regarding population trends. However, it is suggested that the species’ abundance is robust over its entire range. Speckled Dace are bottom feeders that eat benthic insects and consume filamentous algae associated with autochthonous pathways. The primary activities likely to threaten Speckled Dace critical habitat include: excessive water draw-down during late summer (mainly agricultural) and sedimentation from forest operations. It appears that the human induced threats to Speckled Dace habitat have not increased over the last decade. The human population of the Kettle basin has declined slightly in numbers and increased in mean age. Forestry production has declined by 40% over the last decade. There has been a major shift to unregulated groundwater extraction from more regulated surface water withdrawal. The impact of this shift warrants further studies. Recommended critical habitat necessary to maintain the minimum viable population levels is 2.4 km of river (total width) in each of the upper Kettle (East Kettle), West Kettle, and Granby Rivers. Further research should include population estimates within each of the three recommended critical habitat sites to insure these sites contain the population necessary to maintain and recover the species, examination of winter ecology and winter habitat use, and continued research on the extent and effects of groundwater versus surface water extraction. |
