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.

Incidence of parasite infection in adults (histology) C.shasta P.minibicornis IGH FCS 2005 FCS 2006 STT / 20 (80) pending JAN07 9 / 10 (90) c 18 / 20 (90) ab 20 / 20 (100) ab 4 / 10 (40) ab TRH FCS 2005 STT 2005 COHO / 19 (5) 19 / 20 (95) c 16 / 20 (80) d 19 / 19 (100) 16 / 20 (80) ab 3 / 20 (15) ab Feather R FCS 2005 STT / 20 (45) d 10 / 20 (50) 5 / 20 (25) a 0 / 20 (0) CNFH FCS 2003 STT / 60 (47) 3 / 30 (10) 38 / 60 (60) nd

Incidence of parasite infection in adults (histology) Steelhead Cs = not invasive

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

“It takes 3 to tango” I host environment Parasite (pathogen) Disease Replication & temperature Stress, immune function, and temperature Virulence of pathogen(s) Synergism of multiple infections

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

Prognosis of infection Invasion by pathogen None/unsuccessful Disease / death Carrier state Damages self Disease / death predation Disease / recovery Contain / destroy pathogen Host response(s)

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)

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

Incidence of C.shasta & P.minibicornis infection in juvenile chinook in the Klamath R. & estuary, May – July (histology) Cs (KR) = 35 – 50% << Pm (KR) = % Cs drop in KE, different fish (TR influence)

External bacterial and parasitic infections Flavobacterium 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

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 % “normal” survival rate? –Need for in-river survival studies in KR

Appreciation Strong commitment and high level of cooperation for Fish Health work by Klamath fisheries community Meeting organizers