Fish & Wildlife Service Rule on Bull Trout Affects 5 States

The U.S. Fish & Wildlife Service (FWS) final rule designating critical habitat for the bull trout, a threatened species under the Endangered Species Act (the “ESA”), recently took effect. The species’ critical habitat now covers approximately 18,975 miles of streams, 488,252 acres of lakes and reservoirs, and 754 miles of marine shoreline in five states. While the area covered is less than FWS initially proposed earlier this year, it covers five times more marine and freshwater habitat than the USFWS’ 2005 designation. The majority of areas designated occur on federally- and privately-owned waterways in Idaho, Washington, and Montana, followed by substantial miles of streams and acres of lakes and reservoirs in Oregon, and under 100 stream miles in Nevada.

The USFWS map reproduced below shows areas designated as critical habitat (in blue) compared to areas proposed (in red), over 32 discrete critical habitat units (shaded):

In the listing decisions and proposed and final critical habitat rules, the FWS determined that the bull trout’s decline has resulted primarily from habitat degradation and fragmentation, blockage of migratory corridors, poor water quality, poor fisheries management, dams, water diversions, and nonnative species. USFWS determined that those effects have resulted largely from timber harvest, agricultural practices, and road building near riparian areas; operation of dams without effective fish passage features; mining near aquatic systems; introduction of nonnative species that prey upon, hybridize, or exacerbate stresses on bull trout; and urbanization in watersheds.

The FWS also determined that climate change poses additional threats to bull trout, since temperature models predict general air temperature warning by 1 to 2.5 degrees Celsius within the next 40 years, increasing water temperatures. Bull trout need substantially lower water temperatures than other salmonids to survive, and coldwater fish do not adapt well to thermal increases. Accordingly, the FWS determined that “bull trout may be among the species most sensitive to the effects of climate change.”

The rule is designed to provide sufficient habitat to allow for genetic diversity of the species, to ensure bull trout are well distributed, and to ensure sufficient connectivity between populations and allow for the ability to address threats to the species. Of the waterways proposed for designation, the majority of stream and shoreline area is federally owned, followed by privately-owned waterways. The remainder are owned by tribes, states, or jointly by federal/private or federal/state ownership. The Service recently re-evaluated its DPS designations, and identified six “recovery units” for the species, including the following: the Mid-Columbia recovery unit; Saint Mary; Columbia Headwaters; Coastal; Klamath; and Upper Snake. The Service determined that “conserving each [recovery unit] is essential to conserving the listed entity as a whole.” (Marten Law, 12/9/2010)