'Cutts may make endangered listBy Carol Picard
Feb 09 2008
The federal government is considering listing the westslope cutthroat trout as an endangered species in Canada, given its low numbers and rapidly declining population.
The designation, if successful, would only apply to the genetically pure cutthroat which is native to western North America.
The species readily hybridizes with other trout, particularly rainbow, but the genetically pure population is in a precarious position due to competition with non-native fish and habitat degradation, according to an assessment done by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).
The public consultation process under the Species at Risk Act (SARA) opened on Dec. 27 and goes until April 25. After that, depending on the volume and nature of responses received, listing could take anywhere from nine months to a year and a half or more.
The Bow River system in Banff National Park is the fish's most northern habitat, and in 2006, the genetically pure strain of the species was only found in five isolated spots, according to Shelley Humphries, aquatics specialist with the Lake Louise, Yoho and Kootenay Field Unit of Parks Canada.
"It used to be incredibly prolific in the area, but it is really only left now in isolated headwaters" and a few small creeks, Humphries told last week's (Jan. 30-31) Montane Ecosystem Science Workshop in Banff.
"COSEWIC has recognized for a long time that this species is in trouble, and it recommends it be listed as endangered."
The cutthroat, which has black spots clustered along its spine and down to its tail and bright orange-red slashes beneath its lower jaw, can't readily be distinguished from the hybridized cutthroat/rainbow and DNA testing has to be done to determine the pure stock, she said. In 2006, Parks Canada staff electrofished and netted in 19 lakes in the mountain parks, clipping the fishes' fins for DNA sampling. They found pure cutthroat in only five locations.
"We knew about one, the other four were a surprise," she said.
DNA testing on samples taken in 2007 isn't yet complete, she said.
Along with angling, the major threats to the fish in the national parks have been aquatic fragmentation caused by road and dam building and historical stocking practices, in which non-native populations were introduced to lakes and streams for sport fishing.
"We haven't stocked for cutthroat in the park for a long time, but that could be a restoration move in the future," said Humphries, noting, however, "we were prolific - we went far and wide.
"Many areas may look pristine, but under the water surface it's not. There was only one major watershed that was never stocked, the Dorner. Overall, the populations may look fairly pure, but we're seeing a lot of historical hybridization because of the stocking."
Prior to construction of the Spray Reservoir in the 1950s, the province removed pure cutthroat trout and put them in Marvel Lake, from which brood stock is now taken, she said.
Fred Nhytka, a species at risk biologist with Fisheries and Oceans in Winnipeg, said already the federal agency has received numerous requests for further information, primarily from outfitters, sports shops and anglers; not surprising given its popularity as a sport fish.
Anyone is welcome to submit comments outlining how the listing would affect their livelihood or personal lives, Nhytka said.
If the fish are listed as endangered, several prohibitions would be attached to it, including a total ban on catching the fish, unless that is allowed in whatever recovery strategy is drafted. Under the SARA legislation a recovery strategy must be drafted within two years of the listing.
To comment on the proposed listing of the cutthroat visit
www.sararegistry.gc.ca and go through the workbook on the site. The deadline for submissions is April 25.
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