Monitoring Studies

Two approaches are used to monitor the spatial and temporal abundance of Ceratomyxa shasta in the Klamath River.

Sentinel Fish Exposures

In sentinel fish exposures, fish highly susceptible to the parasite (out-of-basin rainbow trout) are placed in cages alongside fish of interest such as native Chinook and coho at index sites along the river for a three day exposure. All fish are transported to the lab (SDL) and monitored for infection (up to three months). Prevalence of infection and severity of infection (percent mortality and mean days to death) are recorded through visual observations and molecular assay (PCR).

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Sentinel fish cages in the Klamath River	Susceptible out-of-basin rainbow trout

Water Samples

Fish 'detect' only the actinospore stage of C. shasta and are labor intensive. To detect total parasite abundance, water samples are taken from mainstem (twice/week) and tributary (twice/month) index sites from March through September. At four sites in 2009, solar powered automatic samplers (ISCOs) collect 0.5L water every 2 hours for 24 hours, from hich four 1L samples are taken. Sampling at the other locations is done manually. Each 1L sample is filtered through a nitrocellulose membrane using a vacuum pump, total DNA is extracted using a kit and a quantitative PCR (QPCR) specific for C. shasta is used to detect and quantify any parasite DNA present. Ct values generated by the QPCR are converted to numbers of parasite spores per liter of water using reference samples with known quantities of spores.

Filtering a water sample using a vacuum pump

Folding the filter paper with captured material

Placing the filter paper into a microfuge for storage at -20C

Polychaetes

To monitor abundance and prevalence of infection in the invertebrate host of C. shasta, polychaete samples are collected annually at three sites in the Klamath River: up-river from the I-5 Bridge ~.5 Rkm, at the Tree of Heaven campground, and down river from the Seiad Creek confluence (~5 Rkm). Three separate samples are collected at each site in May, June and September, using a Hess sampler. The samples have been preserved in alcohol and will be examined for population density, prevalence of infection and qualitative demographics.

Annual Report

Bureau of Reclamation Report for 2008

Page photo credits: S Atkinson & S Hallett

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