Chronic Toxicity of Surface Water from a Canadian Oil Sands End Pit Lake to the Freshwater Invertebrates Chironomus dilutus and Ceriodaphnia dubia.

Chronic Toxicity of Surface Water from a Canadian Oil Sands End Pit Lake to the Freshwater Invertebrates Chironomus dilutus and Ceriodaphnia dubia. Arch Environ Contam Toxicol. 2020 Feb 20;: Authors: White KB, Liber K Abstract Permanent reclamation of tailings generated by surface mining in the Canadian oil sands may be achieved through the creation of end pit lakes (EPLs) in which tailings are stored in mined-out pits and capped with water. However, these tailings contain high concentrations of dissolved organics, metals, and salts, and thus surface water quality of EPLs is a significant concern. This is the first study to investigate the chronic toxicity of surface water from Base Mine Lake (BML), the Canadian oil sands first large-scale EPL, to aquatic invertebrates that play a vital role in the early development of aquatic ecosystems (Chironomus dilutus and Ceriodaphnia dubia). After exposure of C. dilutus larvae for 23 days and C. dubia neonates for 8 days, no mortality was observed in any treatment with whole BML surface water. However, the emergence of C. dilutus adults was delayed by nearly 1 week, and their survival was significantly reduced (36%) compared with the controls. Reproduction (fecundity) of C. dubia was reduced by 20% after exposure to 2014 BML surface water; however, the effect was not observed after exposure to BML surface water collected a year later in 2015. Despite some adverse effects, the results of...
Source: Archives of Environmental Contamination and Toxicology - Category: Environmental Health Authors: Tags: Arch Environ Contam Toxicol Source Type: research