Chronic toxicity of oil sands process-affected water to early life stage wood frogs (lithobates sylvaticus)

Oil sands process-affected water (OSPW) is a by-product of the extraction process of bitumen in the Canadian oil sands industry and is currently stored in tailings ponds on site. Wood frog embryos exposed to waterborne 80% OSPW (containing 9.1 mg/L total naphthenic acids) for 90 days exhibited a 49 ± 11.2% decrease in survival, while no mortality was observed in OSPW treatments between 1.25 to 40%. Development to metamorphosis was significantly delayed in wood frogs exposed to 40 and 80% OSPW treatments. In addition, wood frogs exposed to 20% OSPW showed significantly increased rates of scoliosis and a severe hind limb deformity after 40% OSPW exposure. Organic chemicals within OSPW were evaluated by total naphthenic acid concentrations and biomimetic extraction via solid phase microextraction analytical techniques. The findings of this study are beneficial in understanding the chronic toxicity of OSPW in a North American amphibian species.