2002 Fish die-off/kill

• Report on 2002 Fall Klamath River fish die-off–causes
• September 2002 Klamath River Fish Kill: Preliminary Analysis of Contributing Factors. California Department of Fish And Game [PDF]

In July 2004 the California Department of Fish and Game has issued a final report on the 2002 fish kill on the Klamath River. In this report DFG states that their initial estimate (34,056 fish) of the number of fish killed was conservative and that their final analysis finds that at least twice that number of fish died. The primary cause of death was a disease epizootic resulting from the ubiquitous pathogens ich and columnaris. The presence of these pathogens was exacerbated by an extraordinarily large number of fish in the river between the last week of August and the first week of September 2002. Atypically low river flow and volume which resulted in high fish densities and likely impeded fish movement upstream over riffles, and warm water from the Klamath River created conditions ideal for the amplification of the pathogens and resulted in high fish mortalities. DFG points out that the only currently controllable factor and tool in the Klamath Basin is control of river flow.

California Department of Fish and Game. 2004. September 2002 Klamath River Fish-Kill: Final Analysis of Contributing Factors and Impacts. http://www.dfg.ca.gov/