Alberta’s Provincial Fish in Peril

One of the most often heard arguments against attempting to protect and restore threatened bull trout in the Flathead watershed is that there is no need for us to act  since the species is doing well in other habitats, particularly in western Canada.

The fatal flaw in that argument was again pointed out today by an article in the Calgary Herald.

Bull trout, official Alberta fish species, slides into ‘at-risk’ status

Bull trout are the Provincial fish of Alberta, but the species has been declining there for many years, as it has throughout its range. On Monday, the Committee on the Status of Endangered Wildlife in Canada “declared the populations threatened in the Saskatchewan and Nelson rivers due to habitat deterioration and reduced habitat connectivity.”

Lorne Fitch, a retired biologist, said the bull trout is an important indicator species. “Think of them in the same way you would think about grizzly bears, except these have fins and gills,” he said. “So they are an indicator species of intact systems.

“Think of them as the gold seal of water quality and landscape integrity.”

Fitch said the prognosis for bull trout in Alberta is still dire, with the March report noting 61 per cent of the bull trout core areas are still in decline, while the remaining populations are stable or increasing. Only three of the 51 populations have improved.

Alberta Bull Trout

The declaration for Alberta bull trout follows on the heels of many studies that have found the species to be in danger of the loss of individual populations and perilous decline throughout their range. A recently published study by the Alberta Conservation Association on the distribution and abundance of bull trout in Alberta’s Castle River drainage found that,

Bull trout (Salvelinus confluentus) abundance and distribution have been significantly reduced in Alberta due to habitat fragmentation and degradation, migration barriers, introduction of non-native fish species and overharvest (Alberta Sustainable Resource Development [ASRD] and Alberta Conservation Association [ACA] 2009). The distribution of bull trout in southwestern Alberta drainages, in particular, has declined to an estimated 31% of their natural range (Fitch 1997). Forestry, gas extraction, off-highway vehicle use, random-access camping and livestock grazing are all land-use activities in the Castle River drainage that continue to impact areas adjacent to bull trout streams, and ultimately pose threats to bull trout habitat and survival.

Bull trout were listed as a Threatened Species under the Endangered Species Act in the US in 1998. Much of the impetus for that listing came as a direct result of the precipitous decline in Flathead River bull trout numbers resulting from predation by introduced lake trout in Flathead Lake. Bull trout numbers in the Flathead have declined by more than 60% since the boom in the predatory lake trout population. Bull trout face many threats to their survival, not only in the Flathead Basin and across western Montana as and in Canada, and they continue to be in danger throughout their historic range.

As individual spawning populations of bull trout begin to disappear, we face an imminent population instability, the threat of the loss of genetic diversity to the species and the very real possibility that this ice-age fish will cease to exist in our home waters during our watch. Nearly all of the problems facing bull trout were created by our intervention in their habitat and it is up to us as stewards of this important resource to act to protect and restore these magnificent fish before it is too late.