Synthesis of the Effects to Fish Species of Two Management Scenarios for the Secretarial Determination on Removal of the Lower Four Dams on the Klamath River

In this report, we summarize anticipated effects to fish resources under two management scenarios: 1) current conditions with dams in place and without the programs and actions in the Klamath Basin Restoration Agreement (KBRA), and 2) removal of the lower four dams plus programs and actions called for in the KBRA and KHSA. This information will aid the Secretary of the Interior in determining whether dam removal and implementation of KBRA will advance restoration of salmonid (salmon and trout) fisheries. Species viability would improve for most native anadromous and resident species with dam removal and KBRA implementation. Impacts to federally listed suckers from dam removal would be minimal because reservoirs contribute little to recovery of the species; however, suckers may benefit from improved water quality in the upper basin, and specifically in Upper Klamath Lake, from the programs and actions in KBRA. Salmon fisheries would likely benefit from dam removal coastwide, since the abundances of Klamath River salmon would be less likely to reach levels that restrict commercial fishing through weak-stock management.