EXECUTIVE SUMMARY Limited historical references indicate that bull trout Salvelinus confluentus in Oregon were once widely spread throughout at least 12 basins in the Klamath River and Columbia River systems. No bull trout have been observed in Oregon's coastal systems. A total of 69 bull trout populations in 12 basins are currently identified in Oregon. A comparison of the 1991 bull trout status (Ratliff and Ho well 1992) to the revised 1996 status found that 7 populations were newly discovered and 1 population showed a positive or upgraded status while 22 populations showed a negative or downgraded status. The general downgrading of 32% of Oregon's bull trout populations appears largely due to increased survey efforts and increased survey accuracy rather than reduced numbers or distribution. However, three populations in the upper Klamath Basin, two in the Walla Walla Basin, and one in the Willamette Basin showed decreases in estimated population abundance or distribution. Some Oregon river basins have bull trout populations at extreme risk of extinction. This statewide status review listed only 19% of the bull trout populations in Oregon with a ulow risk of extinction" or "of special concern." Therefore, 81% of Oregon's bull trout populations are considered to be at a "moderate risk of extinction," "high risk of extinction," or "probably extinct." Populations in the Hood, Klamath, and Powder basins, as well as the Odell Lake population in the Deschutes basin, which contain only a few remaining bull trout, are examples of populations having a "moderate" or "high risk" of extinction. Approximately 55% of current bull trout distribution occurs on lands managed by the U.S. Forest Service. A much smaller proportion occurs on Bureau of Land Management managed lands (2%). Only 16% of current bull trout distribution occurs within a protected area defined as Wilderness, Wild and Scenic River, or within a National Park. The Northwest Forest Plan, Inland Native Fish Strategy, and Interim Strategies for Managing Anadromous Fish-producing Watersheds in Eastern Oregon and Washington, Idaho, and Portions of California have provided increased protection for bull trout habitat depending on their scope and geographic areas affected, and the extent to which they are being effectively implemented in watersheds containing bull trout. Recent reduction in timber production on National Forests (up to 50% in western Oregon National Forests and over 30% in eastern Oregon National Forests) should help improve riparian and stream habitat conditions for bull trout. The remaining bull trout distribution occurs on private, state, or tribal owned lands. A comparison of approximately 39 locations throughout the state with protective angling regulations on bull trout (in some areas more than one bull trout population is protected by one regulation) shows that all state managed areas were upgraded in a protective angling status or at least maintained in 1996 compared to 1989. Restrictive angling regulations prohibit angler harvest of all bull trout populations in Oregon except for one in the Deschutes Basin. Restrictive bull trout angling regulation changes (including the elimination of bull Vll trout harvest in all spawning areas) may be the major reasons why the Metolius River/Lake Billy Chinook and mainstem McKenzie River populations have shown significant increases in abundance. Statewide stocking of non-native brook trout, including the high lakes stocking program, has been discontinued in locations where managers believe brook trout could migrate downstream and potentially interact with native bull trout. Hatchery stocking of legal rainbow trout to promote recreational fisheries has been discontinued in most locations near bull trout populations to avoid incidental catch of bull trout. The spatial and temporal distributions of bull trout reported for each river basin in this status report should be used as an accurate baseline for fisheries managers. Current distribution and relative change of distribution should be useful indicators of population health and status. The GIS maps in this report provide a template to add new layers of data such as critical spawning and juvenile rearing areas, or as a method to compare distribution changes through time. Length frequency data are presented for most Oregon bull trout populations. This should provide estimates for the presence of multiple age classes and the percent of fluvial size life history component. Vlll
"October 1997."; Includes bibliographical references (p. 156-168); Electronic reproduction. Portland, OR : Bonneville Power Administration, Environment, Fish, and Wildlife Division, 1997. Errata page inserted. "DOE/BP-34342-5." Mode of access: World Wide Web. System requirements: Adobe Acrobat reader