eDNA Monitoring of Ich in the Klamath River 2020

The YTFP collected water samples from 3 locations on the lower Klamath River. These sites were selected based on their proximity to past ich outbreaks and ease of accessibility. Sampling occurred from June through October with water samples collected on a weekly basis using an automated water sampling machine (isco). Once collected, water samples were taken back to our laboratory to be filtered and the filtrate was frozen and shipped to OSU for analysis. We also planned to conduct 2-3 longitudinal sampling events. These events would take place over the course of a single day with multiple sampling locations spread out over the entire lower Klamath River. Ideally, longitudinal sampling would take place before, during, and after any potential outbreak of ich. This sampling strategy assists researchers in identifying any “hot spots” and possible sources of disease epizootics.

Currently, the YTFP ich monitoring program is through direct, lethal sampling of fish which can insensitive to early or light infections. Sentinel fish exposures are not possible during periods of high water temperature typically associated with Ich outbreaks. Water sampling for ich eDNA will provide valuable insight and compliment any ongoing ich studies and can be utilized as an early warning for disease outbreaks. This is the the most important aspects of this project. Working with OSU, the YTFP has the ability to relay specific real time information to water managers regarding the levels of Ich in the Klamath River. This tangible result can be invaluable when dealing with disease issues on the lower Klamath River.

Project Objective: The objective of this project is to monitor levels of the deadly fish parasite Ichthyophthirius multifiliis (ich) in the lower Klamath River using environmental DNA (eDNA) samples that have been extracted from weekly water collections.

Project Benefit: This project will give researchers and managers an enhanced understanding of the ich lifecycle and how it relates to salmonids. Additionally, information gathered during this project could be used as an early warning to identify possible disease outbreaks and/or fish die offs. This project will also provide data so that management actions (primarily water management related to the operation of the federally owned Klamath Irrigation Project and the Trinity Division of the Central Valley Project) can be improved with respect to their effect on anadromous fish in general, and particularly with respect to ESA-listed SONCC coho salmon and Chinook salmon important to the Yurok Tribe’s subsistence and commercial fisheries.