The U.S. Fish and Wildlife Service has revised the 2005 critical habitat designation for bull trout (Salvelinus confluentus), a threatened species found throughout much of the Pacific Northwest and protected under the federal Endangered Species Act.
Approximately 18,975 miles of streams and 488,252 acres of lakes and reservoirs in Idaho, Oregon, Washington, Montana and Nevada are being designated as critical habitat for the wide-ranging fish. In Washington, 754 miles of marine shoreline are also being designated.
“This action is the result of an extensive review of the Service’s previous bull trout critical habitat proposals and designation, as well as comments and new information received during the 2010 public review process,” said Robyn Thorson, Regional Director of the Service’s Pacific Region. “Our biologists worked hard to ensure the best science was used to identify the features and areas essential to the conservation of bull trout rangewide.”
When compared to the proposed rule issued in January of this year, the designation shows a net reduction of approximately 2,719 miles or 12.5 percent of the streams, 45,174 acres or 8.5 percent of lakes and 231 miles or 23.5 percent of marine shoreline habitat. These changes reflect new biological information received during the comment period resulting in the addition of some habitats and the removal of others, and exclusion of specific areas under section 4(b)(2) of the Act based on ongoing conservation measures, activities, agreements and other factors.
In contrast, the new designation makes significant additions to the habitat designated in 2005. It adds 15,147 stream miles, or roughly 5 times that identified in 2005. Lake and reservoir critical habitat designation increased by 345,034 acres, or about 3.4 times. The amount of shoreline designated is 231 miles less than the 2005 designation.
Approximately 823 miles of streams (4.3 percent of the designation) and 16,701 acres of lakes (3.4 percent of the designation) are not currently occupied by bull trout but are considered essential for the conservation of the species because they provide connectivity between occupied areas. No unoccupied habitat was included in the 2005 designation. The Service revised this designation in part to make it more consistent with existing policy for protecting critical habitat.
“Bull trout depend on cold, clear water and are excellent indicators of water quality,” Regional Director Thorson said. “Protecting and restoring their habitat contributes not only to the recovery of the species but to the water quality of rivers and lakes throughout their range.”
Once plentiful, bull trout were found in 60 percent of the Columbia River Basin but now occur in less than half their historical range, with populations remaining in portions of Oregon, Washington, Idaho, Montana and Nevada. In the Klamath River Basin, bull trout occur in 21 percent of their historical range. They were listed in 1999 as a threatened species throughout their range in the lower 48 U.S. states.
In all, the Service received 1,111 comments from 350 people and organizations across the five states where bull trout occur. Nine public information meetings were held throughout the bull trout’s range, and a formal public hearing was held in Boise, Idaho.
The revised designation, developed by a team of federal scientists with input from peers outside the Fish and Wildlife Service, is intended to provide sufficient habitat to allow for genetic and life history diversity, ensure bull trout are well-distributed across representative habitats, ensure sufficient connectivity among populations and allow for the ability to address threats facing the species.
The final rule identifies 32 critical habitat units on 3,500 water body segments across the five states.
Bull trout are primarily threatened by habitat degradation and fragmentation, blockage of migratory corridors, poor water quality, the effects of climate change and past fisheries management practices, including the introduction of non-native species such as brown, lake and brook trout.
The final critical habitat rule is available for viewing online at the Federal Register. The new designation takes effect on November 17, 2010.