Acute and chronic effects of oil sands process water components on the mayfly Hexagenia and field-collected aquatic macroinvertebrate communities

Abstract

Tailings ponds in northeastern Alberta, Canada contain over one trillion litres of oil sands process water (OSPW) that cannot currently be released due to toxicity of some components. Limited space and the need for reclamation of oil sands operation sites necessitates release of OSPW in the near future. Knowledge of the composition and toxicity of OSPW is often lacking yet is crucial for both risk assessment and management planning. This thesis examines the acute and chronic toxicity of environmentally relevant mixtures of two process water components, naphthenic acid and sodium naphthenate, with and without the added stress of polycyclic aromatic hydrocarbon spiked sediment. We assess the effects of these simplified oil sands process water (OSPW) mixtures under planned and un-planned tailings release scenarios using traditional and novel bioindicators for aquatic invertebrate taxa. The results of this study demonstrate the significant negative effects of OSPW contaminants on aquatic communities.