According to a draft Fish & Game report, the Trinity River lost up to 26% of last year’s fall-run Chinook salmon to the diseases Ich and Columnaris. (For those of you who have lost aquarium fish, these are the same culprits.) Although final reports have yet to be issued, Federal and State biologists working in the Klamath/Trinity River system do know the following: 1) that Ich and Columnaris were the primary causes of death of fish during the 2002 fish die-off, 2) that warm water temperatures, low water velocities, high fish density, and long residence times contribute to major outbreaks of Ich, 3) that water temperatures, river stage, and channel geometry interact to affect adult salmon migration, and 4) that the events of 2002 demonstrate that a major fish die-off can occur during low flow conditions. Our best understanding at this time is that a larger than average run size coupled with low flow conditions contributed to increased localized fish densities and residence times in places of thermal refuge and below riffles. These physical and biological conditions facilitated the transmission and severity of the disease pathogens.

Because these conditions may again be present this summer and fall, District Court Judge Wanger allowed for the potential use of up to 50,000 acre feet of water to help prevent another die-off. On June 26, 2003 the Trinity Management Council (TMC) endorsed a planning approach that included stakeholder input and the development of an Action Plan for submittal to the Bureau of Reclamation. The Trinity River Restoration Program (TRRP) coordinated this effort with participating agencies, tribal governments and various stakeholders. Public input was provided directly to the agency scientists through the TRRP’s Trinity Adaptive Management Working Group (TAMWG), a federally chartered advisory committee. The comments and suggestions from the TAMWG included public safety issues, economic impacts, lake and river recreation, as well as strategies to avoid another die-off. State and federal biologists met on July 23-24 to develop a flow schedule considerate of these comments, and designed to provide in-river conditions known to be adequate for salmon migration.

The TRRP staff then presented the technical group’s recommendations to the TAMWG and TMC. Both groups strongly endorsed the Action Plan, and on August 6, the plan and flow recommendations were sent to the Bureau of Reclamation for consideration. A decision is expected by mid-August.

Although we hope that the circumstances associated with a die-off don’t repeat themselves, all participants felt that the process envisioned by the framers of the Restoration Program worked well to provide local public and agency input into decisions that contribute to the health of the Trinity River and its communities.