Immune Suppression in Fish in response to oil sands‐related compounds in the Wood Buffalo Region

This research investigates the effects of oil sands process-affected materials (OSPM) and oil sands process-affected water (OSPW) on fish health, with particular focus on disease susceptibility as a potential mechanism threatening fish populations in reclaimed landscapes. OSPM waters contain naphthenates, sulfate-based salinity, and polycyclic aromatic hydrocarbons (PAHs)—some of which are known immunotoxins—yet their effects on immune function and disease susceptibility in native Wood Buffalo Region fish species remain poorly understood.

This study demonstrated that contamination negatively affected all three fish species examined—yellow perch, white suckers, and rainbow trout—despite some interspecies variation in response. The observed impacts encompassed multiple biological systems, including increased disease susceptibility, immune system suppression, elevated bile fluorescence indicating hydrocarbon exposure, increased liver metabolic enzyme activity, tissue lesions, developmental abnormalities in hatchlings, reduced hatch size, and decreased testes size.