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.
