The occurrence of viral infections in wild salmonids and escaped farmed salmon in Norway

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1 The occurrence of viral infections in wild salmonids and escaped farmed salmon in Norway Abdullah Madhun TriNation Meeting

2 Risk assessment of the environmental impact of Norwegian Atlantic salmon farming Salmon lice Genetic introgression (escapees) Viral diseases Organic load and nutrients

3 The impact of virus diseases in Norwegian salmon farming on the wild salmonids

4 Viral diseases in Norwegian fish farming Pancreas disease (PD): SAV Heart and skeletal muscle inflammation (HSMI): PRV Infectious salmon anaemia (ISA): ISAV Infectious pancreatic necrosis (IPN): IPNV Cardiomyopathy Syndrome (CMS): PMCV Annual disease outbreaks in Norwegian salmon farming Disease PD HSMI ISA IPN CMS Total Underreported Fiskehelserapporten 2015, Veterinærinstituttet.

5 Can viral diseases in fish faming affect wild Salmon? mill Virus transmission? Frequency / Intensity?? Disease? Reduction in wild stock

6 Virus transmission and effect: can it be measured? Virus screening (real-time PCR) Compare virus occurrence in wild salmonids from areas with different farming intensities and/or disease profile Genotyping of isolated virus (wild or famed) Sentinel (smolt) cages Antibody screening Compare anti-viral antibodies in wild salmonids from areas with different farming intensities and/or disease profile Survival studies (release of vaccinated and unvaccinated smolt)

7 Virus transmission from fish farming Escaped framed fish Sea trout Courtesy of the Atlantic Salmon Trust and Robin Ade

8 Sea trout Finnmark Sogn og Fjordane Hordaland Rogaland Returning adult salmon Finnmark Troms Nordland Hordaland Migrating smolt Sogn og Fjordane Hordaland Presmolt (Parr) Finnmark Hordaland Escaped farmed salmon Finnmark Troms Nordland Hordaland Rogaland Collection sites Fish farming

9 Virus prevalence in sea trout Sea trout (N=843) SAV: not detected PRV: 1.3% 0% 6% 6% Madhun et al. (2016) Dis Aquat Organ

10 Virus occurrence in returning salmon north Norway salmon 42 escaped farmed fish Wild salmon (N=381) SAV : not detected PRV: 8% (5-35%) ISAV: HPR-Δ: not detected HPR-0: 7% (0-20%)

11 Viral infections in returning salmon: west Norway Osterfjord (N=682): SAV: not detected PRV: 14.5 % ISAV: not detected Hardangerfjord (N=400+): Ongoing Fish farming

12 Virus prevalence in migrating smolt Migrating smolt from west Norway (N=671) SAV: not detected ISAV: not detected PRV: 4.5% Sognefjord (N=148): 6% Osterfjord (N=375): 5% Hardangerfjord (N=148): 2% Fish farming PRV in smolt from Osterfjord (N=375 ) Wild smolt: 10% Released smolt: 2%

13 Viral infection in escaped farmed salmon North Norway 2012 (N=41) SAV: not detected PRV: 85% ISAV (HPR0): 5% Hardangerfjord 2012 (N=58, 21 River Steinsdalselva): SAV: 98% PRV: 100% PMCV: not detected Salmon trap in river Etne mainovember 2014 (N=129): SAV: 12% PRV: 79% ISAV (HPR0): 1%

14 Virus infection in presmolt (parr) River Vestre Jakob (N=208) SAV, ISAV, IPNV: not detected PRV: Ongoing River Os (N=333) SAV, ISAV, IPNV: not detected PRV: 3% River Etne (N=85) SAV, ISAV, IPNV, PRV : not detected Fish farming

15 Summary SAV SAV was not detected in sea trout (not susceptible?) SAV was not detected in wild salmon (retuning adults, migrating smolt, parr). Why? SAV is prevalent in recently escaped farmed salmon in endemic areas (12-98%) PRV Low prevalence in sea trout ( 1%). Occur in wild salmons (retuning adults, migrating smolt, parr, 0-50%) Very prevalent in escaped farmed salmon (>75%) ISAV ISAV (HPR- ) was not detected in wild salmonids ISAV (HPR-0) may occur in returning adult salmon (0-7%) ISAV (HPR-0) may occur in escaped farmed fish (1-5%)

16 Virus transmission and effect: can it be measured? Virus screening Compare virus occurrence in wild salmonids from areas with different farming intensities and/or disease profile Genotyping of isolates Sentinel (smolt) cages Antibody screening Compare anti-viral antibodies in wild salmonids from areas with different farming intensities and/or disease profile Survival studies (release of vaccinated and unvaccinated smolt)

17 Viral infection in smolt from sentinel cages 2015 Smolt cages 2015 (N=125) SAV: not detected ISAV: not detected May-June 2015 Fish farming

18 Thanks for your attention. Egil Karlsbakk Ann Cathrine Einen Ingrid Fiksdal Cecilie Helen Isachsen Linn Maren Omdal Ove Skilbrei Vidar Wennevik Stig Mæhle Pål Arne Bjørn Rune Nilsen Kevin Glover Øystein Skaala Terje Svåsand Bjørn Torgeir Barlaup (Uni Research) Kurt Urdal (Rådgivende Biologer) Eero Niemela (RKTL, Finland)