Endangered and Threatened Species: Threatened Status for Two ESUs of Steelhead in Washington, Oregon, and California

Previously, NMFS completed a comprehensive status review of west coast steelhead (Oncorhynchus mykiss, or O. mykiss) populations in Washington, Oregon, Idaho, and California, and identified 15 Evolutionarily Significant Units (ESUs) within this range. After soliciting additional data to resolve scientific disagreements, NMFS now issues a final rule to list two ESUs as threatened under the Endangered Species Act (ESA). The threatened steelhead ESUs are located in Washington, Oregon, and California (Lower Columbia River and Central Valley, California ESUs). NMFS will issue shortly protective regulations under section 4(d) of the ESA for these threatened ESUs. NMFS has determined that the Oregon Coast, Klamath Mountains Province (KMP), and Northern California ESUs do not warrant listing at this time. Available scientific information and conservation measures indicate these ESUs are now at a lower risk of extinction than at the time of the proposed rule. However, NMFS remains concerned about the status of steelhead in these areas; therefore, the Oregon Coast, KMP, and Northern California ESUs warrant classification as candidate species. NMFS will reevaluate the status of these ESUs within four years to determine whether listing is warranted. In the two ESUs identified as threatened, only naturally spawned populations of steelhead (and their progeny) residing below naturally and man-made impassable barriers (e.g., impassable waterfalls and dams) are listed. NMFS has examined the relationship between hatchery and natural populations of steelhead in these ESUs and has assessed whether any hatchery populations are essential for their recovery. At this time, no hatchery populations are deemed essential for recovery (and hence listed) in either of the two listed ESUs. At this time, NMFS is listing only anadromous life forms of O. mykiss.