Brief by Central Staff
Wildlife – June 2004 – Colorado Central Magazine
Although the rainbow trout is often identified with the Rocky Mountains, it’s actually an import from California. The brown trout, another favorite, comes from Germany. The only trout native to our mountains is the cut-throat, which gets its name from a red streak under its mouth.
The cut-throat was abundant during the early days of settlement in Central Colorado, but its numbers soon diminished. Logging and mining were hard on water quality, diversions for irrigation reduced stream flows, the remaining fish were easy to catch, and imported trout species displaced the cut-throat.
Further, genetic purity was threatened because cut-throats and rainbows often interbreed. The cut-throat was reduced to less than 5% of its historic range.
That was the basis for a December 1999, petition to the U.S. Fish and Wildlife Service. Environmental groups asked that one variety, the Colorado River cut-throat, be declared an endangered species.
The Service was supposed to respond in 90 days, but the agency blamed budget and staff cuts for the dealy of more than four years. It eventually responded, though. On April 20, it denied the petition, on the grounds that “Surveys indicate that a significant number of viable, self-sustaining and well-distributed populations are found throughout its historic range.”
Several environmental groups said that wasn’t so, and litigation looms, but it’s unclear whether this involves only the Colorado River cut-throat, or includes other varieties, like the Rio Grande and Yellowstone.
Meanwhile, a researcher at Colorado State University has proposed that global warming could help cut-throats. Scott Cooney explained that competition from other species has pushed cut-throats into high, cold streams. The hatchlings don’t put on much fat under those circumstances, so they don’t spawn as well later in life. If their water were warmer, they could accumulate more fat, which would help at spawning time when the fish quit eating and live off of their accumulated fat.
See, not all of the news about global warming is bad.