Cumulative stressor impacts: towards a holistic measure of salmon health and condition

Speaker: Dr. Kristi M. Miller-Saunders
Genetics and Genomics Section, Fisheries and Oceans, Canada, Pacific Biological Station, BC

Wild salmon are experiencing declines worldwide. Cumulative and synergistic biotic and abiotic stressors associated with climate warming affecting salmon in their vulnerable smolt out-migration stage are critical, but teasing out factors of greatest impact is difficult. An intensive investigation of the role of infectious disease in salmon declines has revealed several pathogens associated with physiological impact, increased risk of predation, and smolt to adult survival trends. More holistic assessments of health are now underway with a new generation of genomic technology, Salmon Fit-Chips. Fit-Chips simultaneously apply curated biomarker panels to identify exposure to biotic (harmful algal blooms, sea lice) and abiotic stressors (temperature, low oxygen, osmotic) and states associated with physiological compromise (inflammation, differential immune activation, viral disease, imminent mortality), all based on small non-lethal gill biopsy samples. Together, these tools are resolving patterns of cumulative stressors and diseases impacting salmon and trout in North America and Norway.