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Bonneville cutthroat trout (Oncorhynchus clarki utah)

Historic Range:
Bonneville cutthroat trout, whose coloration is less vivid compared to other cutthroat species and has large, more evenly distributed spots, was historically found in the Bonneville Basin, including suitable habitat within the Basin portions of Utah, Idaho, Wyoming and Nevada. The dessication of Lake Bonneville 8,000 years ago fractured these populations into five geographic regions.

Habitat requirements:
Like most members of the trout family, Bonneville cutthroat trout require clear, cool, well oxygenated water, naturally fluctuating flows, low levels of fine sediment in channel bottoms, well-distributed pools, stable stream banks and abundant stream cover.

Current population status:
As recently as 30 years ago, scientists believed pure strains of Bonneville cutthroat trout were extinct due to over-harvest, water diversions, hybridization, habitat degradation from mining, logging, grazing and competition with brook and brown trout. However, some pure populations have been found. Today, the USFWS claims that 291 Bonneville cutthroat trout populations occupy an estimated 852 miles of stream habitat and 70,000 acres of lake habitat. This is between 5 percent and 17 percent of the subspecies historical range. However, these figures paint an overly-optimistic picture of the conservation status of Bonneville cutthroats. Most of the existing populations are very small (or occupy a very small length of stream) and fall below the population size or occupied stream length required for long-term survival. In addition and despite claims to the contrary, many of these populations are actually hybridized with other cutthroats or are of unknown genetic status.

Threats to continued persistence:
Bonneville cutthroat trout currently face threats from water diversions, habitat damage from livestock grazing and competition from non-native trout species, including continued stocking of nonnatives. In addition, a very large portion of Bonneville cutthroat populations exist within National Forests in areas open to resource development and extraction such as industrial logging and logging road construction.

Listing status as of 6/15/02:
In 1979, the Desert Fishes Council and American Fisheries Society filed a petition with the US Fish and Wildlife Service (USFWS) to list the Bonneville cutthroat trout under the Endangered Species Act. In 1984, the USFWS determined that listing was "warranted but precluded" by higher priority activities. In 1992, the Desert Fishes Council and Utah Wilderness Alliance [sic] again petitioned the USFWS to list this fish. In early 1998, the Biodiversity Legal Foundation filed a new petition to list the Bonneville cutthroat. In December, 1998, the USFWS announced that the petition presented substantial information indicating that listing may be warranted and initiated a status review for the Bonneville cutthroat. In October 2001, the USFWS denied the listing petition. The Western Native Trout Campaign has analyzed the USFWS status review and found significant deficiencies and overly optimistic assumptions. Legal action is under consideration. Interesting Tidbit: It is interesting to note that many of the known populations occur within the Wasatch-Cache National Forest in northeastern Utah.