Ceratonova shasta Monitoring Studies in the Klamath River

Life cycle of Ceratonova shastaCeratonova shasta is a freshwater, myxozoan parasite that is native to the Pacific North West of North America. It causes enteronecrosis in juvenile salmonids and is associated with population-level impacts in the Klamath River. Transmission occurs through waterborne stages: actinospores released from annelids infect salmonid fishes and in the fish's intestine develop into myxospores which then infect annelids (see the life cycle on the right). The parasite proliferates in each host.

In response to the high prevalence and severity of C. shasta-infection in Klamath salmonids, we developed a parasite monitoring program to track the spatial and temporal abundance of C. shasta. The three main approaches are based on the parasite's life cycle and include sentinel fish exposures, annelid host sampling and molecular quantification of parasite DNA in water samples. These are described in more detail below. Monitoring occurs at established index sites which are shown on the following map.

 

Map of monitoring index sites on the Klamath River

Klamath River Index Sites with site abbreviations and river kilometers (Rkm).

Iron Gate Dam (Rkm 306) blocks anadromous salmonid migration.

 

 Sentinel Fish Exposures

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

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 in-basin Chinook and coho salmon at index sites along the river for a three day exposure. All fishes are transported to OSU's John L Fryer Aquatic Animal Health Lab and monitored for infection (~ 60 days). Severity of infection (percent morbidity and mean days to morbidity) are recorded through visual observations and molecular assay (PCR).

2022 DATA UPDATES:

An April sentinel fish exposure occurred 04/18 - 04/21 at KBC and KSV with IGH Fall Chinook and out of basin rainbow trout.

A May sentinel fish exposure occurred 05/19 - 05/22 at WMR and KED in the upper basin and at KI5, KBC, KSV and KOR in teh lower basin.

A third sentinel fish exposure occurred June 13 - 16.

A September exposure is also planned.

 

 

Water Samples

Barth Monitoring filtering
 Barth Monitoring filter paper

 Filtering a water sample
using a vacuum pump

 Folding the filter paper
with captured material

To detect and quantify waterborne stages of C. shasta, river water samples are collected at five mainstem index sites; once a week all year round at two sites (KBC and KSV) and once per week from April through October at three other sites.  Solar-powered automatic samplers (ISCOs) collect 1L water every 2 hours for 24 hours, from which 4 1L samples are manually taken (see photos below). Each 1L sample is filtered through a nitrocellulose membrane using a vacuum pump, and any captured DNA in 3 of the replicate samples is extracted using a kit (see images on right). A quantitative PCR (qPCR) specific for C. shasta is used to detect and quantify any parasite DNA present. Cq values generated by the qPCR are converted to numbers of parasite spores per liter of water using reference samples with known quantities of spores. The Karuk and Yurok tribal biologists are integral to the collection and filtration of the water samples. Water samples are also taken in conjunction with the sentinel fish exposures; manual 'grab' samples are collected on the first and last day of the exposure. Data are presented as the average spores per liter of three replicate 1 liter water samples collected at each site and time.

2022 DATA UPDATES:

During Winter, sampling occurs only at two index sites, KBC and KSV. Spatial sampling will increase to six sites in Spring.

OSU received and processed Klamath River water samples from the 2 winter sites (KBC, KSV) up to 02/15/2022
             KBC      KSV    KTC
12/13       1          0
12/20     <1        <1
01/03       0          0
01/18       0          0
02/08       0          0
02/15       0          0
02/22       0          0
03/01      0          0
03/08      0          0
03/15      0          0
03/22      0          0           1 spore per liter
No C. shasta has been detected at either of the 2 winter sites (KBC, KSV) through 03/15/2022, a pattern consistent with most previous years (see graph below). Sampling commenced at KTC on 03/14 and C. shasta DNA was detected in each of the three replicate samples. Expedited sampling at all index sites has now commenced (final week of March). 
 
03/28/2022 

This was the first week of the 2022 season when all sites were sampled. Samples were taken either by ISCO automatic sampler "i" and are given as the average density of C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday March 27-28), or taken manually "g" (3 x 1-L samples taken Monday March 28). 

C. shasta DNA was detected at 5 of the 6 index sites, with density increasing downstream to up to an average of 5 spores per liter at the lowermost site, KTC. Full sequencing (all genotypes via Sanger sequencing) of subsamples of the lowermost sites is underway and genotype II analysis will commence this week.

KI5  0 i
KBC  <1 i
KMN  1 i
KSV  2 i
KOR  4 i
KTC  5 g

4/04/2022

This was the second week of the 2022 season when all sites were sampled. Due to a shipping misalignment, KTC data will be delayed to next week. Samples were taken either by ISCO automatic sampler "i" and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday April 3-4), or taken manually "g" (3 x 1-L samples taken Monday April 4).

This week, C. shasta DNA was detected at all sites measured. Density at all sites increased over the past week – it more than doubled at all sites. Densities ranged from 3-20 spores per liter. The highest density was at the most downstream sites, with more than 10 spores per liter measured at both KSV and KOR (but note that KSV were grab samples).

KI5 3 i
KBC 7 i
KMN 6 i
KSV 20 g
KOR 12 i
KTC 30g

A second qPCR assay was run on the samples to determine the density of C. shasta genotype II (relevant to coho salmon). All samples tested negative for genotype II.

04/11/2022

This was the third week of the 2022 season when all sites were sampled.

Samples were taken either by ISCO automatic sampler "i" and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday April 10-11), or taken manually "g" (3 x 1-L samples taken Monday April 11).  This week's data also include last week's KTC samples that were not processed earlier due to a shipping misalignment.

Spore density was at or above 10 spores per liter at all six index sites. Similar to last week, spore denstiues were lowest at the upstream sites and highest at the downstream sites. Last week's KTC samples had the highest spore density of the year so far @ 30sp/L, decreasing to 23 this week (highlighted). Densities at the uppermost three sites and KOR were 2-3 times higher this week. Densities at KSV were similar bewteen the two weeks 

KI5  10 i
KBC  15 i
KMN  19 i
KSV  22 g
KOR  23 i
KTC  23 g

04/18/2022

This was the fourth week of the 2022 season when all sites were sampled. This week's sampling was during the prescribed surface flushing flow event.

Only two sites were sampled by ISCO automatic sampler "i" and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday April 17-18), the rest were taken manually "g" (3 x 1-L samples taken Monday April 18).

Densities were lower than the previous week, except at the lowermost site KTC, and remained above 10 spores per liter at 5 of the 6 sites (exception KI5). Again, densities were lowest at the uppermost site KI5 with 4 spores per liter measured then increased downstream to the lowermost site KTC with 26 spores per liter detected.

Coho-relevant Cs genotype data in spores per liter are also given: levels remain <1 sp per liter or not detectable (n.d.).

KI5   4 g         n.d. 
KBC  11 i       n.d.
KMN  12 i      n.d.
KSV  12 g     <<1
KOR  17 g      <1
KTC  26 g       <1

04/25/2022

This was the fifth week of the 2022 season when all sites were sampled. This week's sampling was the first after the prescribed surface flushing flow event.

Three sites were sampled by ISCO automatic sampler "i" and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday April 24-25), the rest were taken manually "g" (3 x 1-L samples taken Monday April 25). Site KTC had both automatic and manual samples taken.

Spore densities were above 10 spores per liter at 5 of the 6 sites sampled this week (all except KTC). Density increased at the three uppermost sites and decreased at the lowermost sites, compared to the previous week. The uppermost site increased three fold whereas the lowermost site decreased three fold. Density decreased as sampling progressed downstream, with the highest densities measured at KI5, KBC & KMN (14-15 sp/L) and the lowest at KTC (7 sp/L). 

Coho-relevant Cs genotype data in spores per liter are also given: for the first time this year this genotype was detected at all sites, however the levels at the upmost three sites are only just detectable. The genotype was detected at lower river sites at levels up to 1 spore per liter (a maximum of about 10% of the total C. shasta spore density, at KSV).

KI5 15 g     <<1
KBC 14 i    <<1
KMN 15 i   <<1
KSV 11 g       1
KOR 11 g    <1
KTC 7 g      <1
KTC 7 i     <<1

05/02/2022

This was the sixth week of the 2022 season when all sites were sampled. Results were delayed several days due to technical problems.
 
The two uppermost sites (KI5, KBC) and lowermost site KTC were sampled by ISCO automatic sampler "i" and are given as the average density of total C. shasta spores per liter of river water (from 1-L subsamples of a 24-hour composite sample, Sunday-Monday May 01-02), the rest were taken manually "g" (1-L samples taken Monday May 02). Field teams experienced some difficulties filtering water this week due to suspended fines, resulting in longer filtration times and the need for twice as many filter membranes at most sites.
 
Densities of C. shasta measured the week of May 2nd were below 10 spores per liter at all index sites. Densities were lower this week compared to the previous week at all sites except KTC. However, this week's data are derived from single 1L samples per site rather than being an average of 3 1L samples. Coho-relevant Cs genotype data will be provided with the next week's samples.
 
KI5   3 i
KBC  8 i 
KMN  8 g
KSV  6 g
KOR  3 g
KTC  9 i
 
05/09/2022

This was the seventh week of the 2022 season when all sites were sampled.

All sites were sampled by ISCO automatic sampler "i" and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday May 8-9). 

The density of C. shasta continued to decrease over the past week with an average of 1 or fewer spores per liter measured throughout the lower basin. All sites have returned to an early spring pattern of very low levels of C. shasta. Interestingly, a similar decrease in spore levels happened in almost the same week in 2020 and 2021. 

KI5 1 i
KBC <1 i
KMN <1 i
KSV <1 i
KOR 1 i
KTC <1 i

05/16/2022

Five of the six index sites were sampled by ISCO automatic sampler "i" and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday May 15-16), site KI5 (like usual) were taken manually "g" (3 x 1-L samples taken Monday May 16). 

The density of C. shasta remained low at all 6 sites, although more C. shasta was measured at the three lower-river sites than the three upper river sites (1-2sp/L versus <1 sp/L).

Coho-relevant C. shasta genotype data will be forthcoming, but will not exceed that of total spore density (i.e. <2 sp/L).

KI5   <1 g
KBC  <1 i
KMN  <1 i
KSV  1 i
KOR  2 i
KTC  1 i

05/23/2022

All sites were sampled by ISCO automatic sampler "i" and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday May 22-23).

All sites have slightly higher C. shasta densities compared with the previous 2 weeks. Densities ranged from 2-4 spores per liter, the highest measured at the lowermost site, KTC. Only trace amounts of Coho-relevant genotype II were detected, at 5 of the 6 sites.

site / total Cs / sample type / coho-genotype

KI5    3 i   <<1
KBC  3 i   <<1
KMN  2 i   <1
KSV   2 i   <1
KOR  3 i   <1
KTC  4 i   not detected

05/30/2022

This was the 10th week of the 2022 season when all sites were sampled.

All sites were sampled by ISCO automatic sampler "i" and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday May 30-31).

All sites have increased densities of C. shasta, with all except KOR above 5 sp/L. Two sites, KI5 and KBC, exceeded 10 spores per liter (11 spores/L).

Coho-relevant Cs genotype data in spores per liter are also given: this genotype was present at all sites, but at a density <1 spore/L.

Average spores per liter:

Site   Total      Genotype II

KI5      11 i       <1
KBC    11 i      <1
KMN     7 i      <1
KSV      6 i     <1
KOR     4 i      <1
KTC     9 i      <1

06/06/2022

This was the 11th week of the 2022 season when all sites were sampled, and the final week when samples will be expedited to have data available the same week - future week's data will be delivered in the timeframe of 1-2 weeks after collection.

All sites were sampled by ISCO automatic sampler and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday June 05-06). 

Site                 Average spores per liter

           Total (= all genotypes)       Genotype II

KI5          7                                            1
KBC        7                                            1
KMN       6                                           <1
KSV        3                                            1
KOR       1                                           trace
KTC        3                                          trace

The density of waterborne C. shasta decreased at all sites over the past week. Densities in the lower basin were below 10 spores per liter, ranging from 1 - 7 spores per liter. Densities at the uppermost three index sites (KI5, KBC & KMN) were twice that measured at the lowermost three sites (KSV, KOR & KTC).

Coho-relevant genotype II was detected throughout the lower basin but at low density of up to 1 spore per liter.

06/13/2022

All sites were sampled by ISCO automatic sampler and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday June 12-13).

Waterborne C. shasta was detected throughout the lower basin June 12-13th but did not exceed an average of 10 spores per liter at any index site. Densities ranged from 3 spores per liter at KSV to 7 spores per liter at KI5, KMN and KTC.

Genotype II (coho-relevant) was detected at low densities (up to an average of 1 spore per liter) at 5 of the 6 sites sampled.

Site

Average spores per liter

 

Total C. shasta (= all genotypes)

Genotype II

KI5

7

<1

KBC

4

<1

KMN

7

1

KSV

3

1

KOR

5

not detected

KTC

7

<1

 

 

 

 

 

 

 

 

 

 

 


06/20/2022

All sites were sampled by ISCO automatic sampler and are given as the average density of total C. shasta spores per liter of river water (from 3 x 1-L subsamples of a 24-hour composite sample, Sunday-Monday June 19-20). 
Densities of C. shasta remained below 10 spores per liter throughout the lower basin (at the 6 index sites sampled), ranging from 2 (at KSV) to 9 (at KOR) spores per liter.
Genotype II (coho-relevant) was detected at low densities (up to an average of 1 spore per liter) at the 6 sites sampled.
 

Site

Average spores per liter

 

Total C. shasta (= all genotypes)

Genotype II

KI5

4 <1

KBC

4 <1

KMN

8 1

KSV

2 <1

KOR

9 <1

KTC

6 <1

 

 

 

 

 

 

 

 

 

 

06/27/2022

All sites were sampled by ISCO automatic sampler and are given as the average density of total C. shasta spores per liter of river water (from 3 x 1-L subsamples of a 24-hour composite sample, Sunday-Monday June 26-27). 
The density of C. shasta exceded 10 spores per liter at one lower basin index site, the lowermost, KTC; density ranged from 2 to 7 spores per liter at the other 5 index sites.
Genotype II (coho-relevant) was detected at low densities (up to an average of 1 spore per liter) at the 6 sites sampled.
 

Site

Average spores per liter

 

Total C. shasta (= all genotypes)

Genotype II

KI5

5 <1

KBC

7 <1

KMN

3 <1

KSV

2 <1

KOR

6 <1

KTC

13 1
 
 
 
 
 
 
 
 
 
 
 
 
 

 

 

 

07/05/2022 & 07/11/2022

All sites were sampled by ISCO automatic sampler and are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Monday-Tuesday July 04-05, and Sunday-Monday July 10-11). Additional manual/grab samples were taken at KTC 7/11/2022.
Per schedule, KMN monitoring and Genotype II (coho) assaying have finished for the year.
 

The density of waterborne C. shasta increased at all five index sites from the week of June 27th to July 5th. Densities ranged from an average of 9 spores per liter at KBC to up to 19 spores per liter at KTC. Density was above 10 spores per liter at 4 of the 5 sites measured.

The density of waterborne C. shasta decreased at all five index sites from the week of July 5th to July 11th. Densities ranged from an average of 5 spores per liter at KBC to up to 11 spores per liter at KSV. Density averaged 10 spores per liter or higher at 2 of the 5 sites measured.

07/05/2022

Site

Average spores per liter

 

Total C. shasta (= all genotypes)

 

KI5

17  

KBC

9  

KSV

18  

KOR

12  

KTC

19  

 

 

 

 

 

 

 

 

 
 
07/11/2022

Site

Average spores per liter

 

Total C. shasta (= all genotypes)

 

KI5

6  

KBC

5  

KSV

11  

KOR

7  

KTC

10  
KTC (grab) 20

 


 
 
 
 
 
 
 


 

-

 

 

 

 
All sites are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite sample, Sunday-Monday July 17-18 and 24-25). Spore densities increased between July 11th and 18th, then decreased over the following week (July 18 - 25) to below 10 spores per liter throughout the lower basin; most recently, densities ranged from 0 (at KTC) to 9 (at KTC) spores per liter. 
 
7/18/2022

Site

Average spores per liter

 

Total C. shasta (= all genotypes)

KI5

13

KBC

8

KSV

8

KOR

7

KTC

4

 

 

 

 

 

 

 

 

 

 

 

7/25/2022

Site

Average spores per liter

 

Total C. shasta (= all genotypes)

KI5

5

KBC

2

KSV

4

KOR

0

KTC

9

 

 

 

 

 

 

 

 

 

 

 September 19th, 2022

Water collection by Karuk and Yurok tribal biologists occurred weekly through summer at 5 index sites, and will continue do so through next month, October.

Water samples are missing from several dates/sites some weeks in August-September due to site access problems due to wildfires, and to sample collection and quality issues related to high waterborne sediment loads following the fires and continuing into late September. These sediment loads have impeded both filtering and subsequent DNA analysis. This results in missing data points as indicated in the plots below (notated with an 'X').

The most recent water sample data are for 9/19/2022, and are a combination of automatic ISCO samples and manual grab "g"  (where ISCO data are unavailable due to machine blockage or failure due to river/water conditions). "Inhibition" indicates some degree of sample contamination with sediment, which necessitated analysis at higher dilution, where possible, (this has been an issue August-September, and may remain a problem for the rest of this year).

Values are given as the average density of total C. shasta spores per liter of river water (from 3x 1-L subsamples of a 24-hour composite ISCO sample, Sunday-Monday September 18-19, or grab sample Monday 19). 

Waterborne densities were below 10 spores per liter the past month and for the most recent week, Sept 18-19, were just 1-3 spores per liter (highest at KTC).

 

Site

Average spores per liter

 

Total C. shasta (= all genotypes)

KI5

2

KBC

2

KSV

1 g (inhibition)

KOR

1 (inhibition)

KTC

3 g

 

 

 

 

 

 

 

 

 

 

 Abundance of Ceratonova shasta in 1L water samples collected from the Klamath River index site Beaver Creek in 2022
Density (average spores per liter) of Ceratonova shasta in 24-hour composite water samples collected at the mainstem long term index site, near Beaver Creek (KBC), in 2022 (blue data points) compared to 2015 (gray shading), 2020 (pink shading), and 2021 (green shading).

 

Abundance of Ceratonova shasta in 1L water samples collected from the Klamath River index sites in 2022

Density (average spores per liter) of Ceratonova shasta in 24-hour composite water samples collected at the mainstem index sites in 2022. Note that KMN is sampled only during salmonid outmigration, KBC and KSV year round and remaining sites April through October. KBC = near Beaver Creek, KSV = Seiad Valley, KI5 = near I5 bridge, KTC = Tully Creek, KMN = Kinsman Fish Trap, KOR = Orleans.  The line denotes 10 spores per liter which corresponds with 40% mortality threhold in Chinook salmon.

 

 Abundance of Ceratonova shasta in 1L water samples collected from the Kalmath River in 2021

Density (average spores per liter) of Ceratonova shasta in 24-hour composite water samples collected at the mainstem index sites in 2021. Note that KMN is sampled only during salmonid outmigration, KBC and KSV year round and remaining sites April through October. KBC = near Beaver Creek, KSV = Seiad Valley, KI5 = near I5 bridge, KTC = Tully Creek, KMN = Kinsman Fish Trap, KOR = Orleans.  The line denotes 10 spores per liter which corresponds with 40% mortality threhold in Chinook salmon.

Manual water sampling by Larry Alameda at Klamath River index site K-I5

Manual water sampling by Larry Alameda at Klamath River index site KMN Collection of 4 1L replicate water samples from 12L composite at KSV Manual water sampling by Larry Alameda at Klamath River index site KOR

Manual water sampling by  Karuk Tribal Biologist Larry Alameda at index site K-I5

Solar powered automatic sampler at the Kinsman index site. An ISCO is used at all index sites but manual sampling provides a backup. Collection of 4 1L technical replicate water samples from the larger 12L composite collected over 24 hours at KSV

Manual water sampling at Orleans index site.

Photos courtesy of Karuk Tribal Biologist Larry Alameda

Genotyping: There are multiple genetic types or genotypes of C. shasta simultaneously present in the Klamath River. These differentially disease the various salmonid species. For example, type I causes mortality in Chinook salmon whereas type II can be fatal for coho salmon. Type 0 is found in sympatric Oncorhynchus mykiss (steelhead and redband rainbow trout).

Therefore, we also genotype each water sample using a qPCR that amplifies the variable ITS1 region and then we sequence that amplicon. From the sequencing chromatogram, we can determine the proportion of each genotype present in a sample. We use the total spore density to then determine the number of spores of each genotype in a sample. 

 

2022 DATA UPDATES

04/04/2022

Ceratonova shasta DNA was detected at all sites, however, genotype II was detected only at the lowermost site, KTC with a density of <1 spore per liter.

04/11/2022

Low densities of genotype II was detected at the three lowermost sites (densities in spores per liter):

KI5  0
KBC  0
KMN  0
KSV  <1
KOR  <1
KTC  <1

Please see above for genotype II updates. (Combined with total C. shasta density) Densities have remained low at index sites this year.

Average spore density of Ceratonova shasta genotype II at Klamath River index sites 2021
Density (average spores per liter) of Ceratonova shasta genotype II in 24-hour composite water samples collected at the mainstem index sites in 2021. Note that KMN is sampled only during salmonid outmigration, KBC and KSV year round and remaining sites April through October. KBC = near Beaver Creek, KSV = Seiad Valley, KI5 = near I5 bridge, KTC = Tully Creek, KMN = Kinsman Fish Trap, KOR = Orleans. The line denotes 5 spores per liter which corresponds with a 40% mortality threhold in coho salmon.

 

Annelid Sampling

Polychaete sampling

 

Polychaete sampling

Manayunkia occidentalis tubes from the image on right A high density assemblage sample at TOH
   

Diver collecting a benthic sample from boulder substrate at the TOH reach. We use a modified Hess sampler fitted with 80um Nytex mesh netting and a 500mL Nalgene collection bottle. Samples are preserved in ethanol until processing. 

Benthic samples are fractioned prior to sorting.

 

 

Dr. Alexander photographing annelids on riprap substrate at the KBC monitoring site.

Annelid sampling at the KI5 reach. Foreground diver measures depth and velocity, while background diver measures substrate grain sizes.

 

To monitor abundance and prevalence of C. shasta infection in the invertebrate annelid host, Manayunkia occidentalis, benthic samples are collected annually at seven sites in the Klamath River. Sites span a discharge gradient; 2 are located in the upper basin downstream from Keno Dam, 3 are located in the middle basin downstream from Iron Gate Dam, and 2 are located in the lower basin downstream from the Scott River. Samples are routinely collected in fall, winter, spring, and summer, and are scheduled to occur more frequently if flooding or pulse flow events are planned. Samples are processed to determine density, simple demographics, and prevalence of C. shasta infection.

 

 

 

2021 DATA UPDATES: 

Annelid sampling occurred in March, April, May, July, and October. In the middle river basin (the infectious zone) in March, the prevalence of C. shasta infection ranged from 3.25-6.8%. This was concerning because densities of M. occidentalis (annelid hosts) were above average. Benthic samples collected from sites located in the infectious zone in spring (April, May), summer and fall also returned above averages densities of M. occidentalis.  Infection prevalence data are in progress. 

 

The next sample collection is planned for March 2022.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ANNUAL REPORTS

Annual reports for Bureau of Reclamation funded studies for 2015 onwards are available. Please contact Sascha Hallett (hallettsAToregonstate.edu). Annual reports are submitted June 1 the year after the research year.

 

ANNUAL KLAMATH RIVER FISH HEALTH WORKSHOP

The latest workshop was held virtually via Zoom on Tuesday March 16th, 2021.

Link to the Agenda.

Graphical abstracts from the workshop.

The next workshop is being planned for summer 2022.

 

Redescription of the invertebrate host:

 

For a lyrical rendition with more information, enjoy: The Ballad of Ceratonova shasta

 

 'Tully Creek' Longitudinal Water Sampling

Parasite levels at our lowermost index site, Tully Creek (at ~60 Rkm), have increased over the past several years to surpass those detected at previously high sites, such as Beaver Creek (KBC). To investigate the extent of the high parasite densities at the Tully Creek site, we sampled water downstrea m (beginning at the lowermost road-accessible location, ~38.4Rkm) and upstream of the index site at Orleans (~90Rkm). Link to report.

 

Data shared here are preliminary and subject to modification.

Page photo credits: S Atkinson, S Hallett & J Alexander

Monitoring Studies are Primarily Supported by the Bureau of Reclamation.