Effects of bituminous contaminants on fathead minnows (Pimephales promelas) of the Lower Athabasca River Basin

Abstract

The lower Athabasca River basin of northern Alberta, Canada is situated within bitumen-rich deposits, where oil sands development is a common occurrence. A transplant and chronic exposure experiment between sites containing natural bitumen (NB) and natural bitumen-oil sands area of industry (NB-OSA) was conducted using fathead minnows (Pimephales promelas). Reference fish chemosensation and respiration was impaired and lowered, respectively, to levels observed in the fish NB-OSA of industry after having been transplanted to either contaminated sites. Fish previously exposed to contaminants had lower olfactory acuity and respiration rates than reference fish, remaining unchanged after exposure at either site. Fish pre-exposed to contaminats exhibit limited ability to deal with additional stressors compared to reference fish, as observed by the lower survival rates in these bituminous fish populations. This limited stress coping capabilities demonstrate native fish populations do not possess an advantage within the aquatic systems in the basin.