u.s. fish & wildlife service overview of infection and disease problems in the klamath river...
TRANSCRIPT
![Page 1: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/1.jpg)
U.S. Fish & Wildlife Service
Overview of infection and disease problems in the Klamath River
basin.
J.Scott Foott
CA-NV Fish Health Center
The findings and conclusions in this presentation have not been formally disseminated by the USFWS and should not be construed to represent any agency determination or policy.
![Page 2: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/2.jpg)
concepts• Infection is not equivalent to disease
– Infection = parasite can establish & replicate itself within host (all fish have parasites)
– Disease = deviation / interruption in normal function
• Many protozoans, helminths, commensal bacteria, (virus ?? Rare) are present in KR fish. Meeting focus on Cs & Pm
![Page 3: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/3.jpg)
“It takes 3 to tango”
• I host
environmentParasite (pathogen)
Disease
Replication & temperature
Stress, immune function, and temperatureVirulence of
pathogen(s)
Synergism of multiple infections
![Page 4: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/4.jpg)
Infectious load (challenge)
• Severity of Ceratomyxosis in Klamath River suggests a shift in the host: parasite balance towards C.shasta– Chronic exposure to high levels of
actinospores overwhelm resistance– Biological question = model probability of
infection and disease with duration of rearing in KR
![Page 5: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/5.jpg)
Prognosis of infection
Invasion by pathogen
None/unsuccessfulDamages self
Contain / destroypathogen
Disease / deathCarrier state
Disease / deathpredation
Disease / recovery
Host response(s)
![Page 6: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/6.jpg)
Transmission
• Contact- attach&invade- multiple in host
• Congregation of juveniles and adults in thermal refugia enhance transmission of some bacteria and parasites– Fc and ICH (not Cs & Pm)
![Page 7: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/7.jpg)
synergism
• Cs (enteritis) + Pm (glomerulonephritis) + external infections (ion loss)
• Evidence of progressive disease leading to mortality in KR salmon under summer temperature conditions– 2002 3d exposure = >80% mortality 17d– 2006 studies
![Page 8: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/8.jpg)
Incidence of C.shasta & P.minibicornis infection in juvenile chinook in the Klamath R. & estuary, May – July (histology)
0102030405060708090
100
CS PM
Cs (KR) = 35 – 50% << Pm (KR) = 47 -92%
Cs drop in KE, different fish (TR influence)
![Page 9: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/9.jpg)
External bacterial and parasitic infectionsFlavobacterium columnare and Ich
• Fc = 3 – 57% POI– > 20C temperatures– disease problem of
adult salmon (02 event)
• Problem in all live box exposure studies in KR
• Ich = both adult and juvenile fish
![Page 10: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/10.jpg)
IMPACT ?
• 70 – 90% mortality estimates for Chinook fry & smolt stage due primarily to predation – MC Healey (Chinook Chapter – Pacific Salmon life histories eds
Groot & Margolis)
• Additional influence of > 35% dual parasite infection on the 10- 30% “normal” survival rate?– Need for in-river survival studies in KR
![Page 11: U.S. Fish & Wildlife Service Overview of infection and disease problems in the Klamath River basin. J.Scott Foott CA-NV Fish Health Center The findings](https://reader035.vdocuments.site/reader035/viewer/2022062717/56649e455503460f94b3a842/html5/thumbnails/11.jpg)
Appreciation
• Strong commitment and high level of cooperation for Fish Health work by Klamath fisheries community
• Meeting organizers