Groves

Infectious Salmon Anemia (ISAv) and Climate Change; the Combined Effects on Atlantic Salmon’s (Salmo salar) Immunological Response

1Laura I. Groves, 1Shona K. Whyte, 1Sara L. Purcell, 1Kathleen Parrish, 1Jonathon Perreira, 2Amber Garber, 1Mark D. Fast

1Department of Pathology an Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI; 2Huntsman Marine Science Centre, St. Andrews, NB

ABSTRACT

Canadian aquaculture experiences millions in economic losses each year from the health effects infectious salmon anemia has on Atlantic salmon. As climate change continues to increase ocean temperatures worldwide, the industry must determine what effect this changing environment will have on important disease dynamics, such as ISAv, on the immunological response of cultured fish, and how they can appropriately adapt. Half and full-sib (n=20) crosses, with 120 fish from each, were cohoused in 38 different tanks for this study. Half of the tanks were acclimatized and maintained at 10°C (95-100% oxygen saturation), while the other half were acclimatized and maintained at 20°C (80-85% oxygen saturation). ISAv isolate (HPR4) with a virulence of TCID50 of 1x105/ml was IP-injected into donor Atlantic salmon. Each study tank had six donor fish added one week post injection (ratio of 1:7, donor to naïve cohabitants). Percent mortality was calculated at the end of the study for each of the 20 genetic lines. Different temperatures and genetic lines displayed a difference in survivorship. Immune gene expression was then used to assess the antiviral responses of the three families that were most susceptible (highest mortalities) and the three families with the most resistance (lowest mortalities). Differences that genetic background and temperature had on anti-viral responses will be discussed in relation to resistance or susceptibility.

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