Cooperative Fish and Wildlife Research Units Program: California
Education, Research and Technical Assistance for Managing Our Natural Resources

The objective of this project is to generate a predictive model of weekly waterborne Ceratonova shasta parasite spore density to improve estimates of mortality risk for juvenile salmonids in the Klamath River. C. shasta is a parasite endemic to the Klamath River basin that has been linked to population declines in native salmonids. High densities of waterborne spores of the parasite are known to cause increasing infection and mortality risk for juvenile salmonids. A recently constructed population dynamics model for Klamath River salmonids, the Stream Salmonid Simulator (S3 model), includes a sub-model to simulate C. shasta disease and mortality risk for outmigrating juveniles in response to potential management alternatives. We have partnered with the U.S. Fish and Wildlife Agency for this project. Developing models that are able to better estimate mortality risk for juvenile salmonids will provide a means to incorporate these models into the S3 model. This then provides an adaptive management tool for managers to understand how different management decisions (e.g. flow) might affect the population.