Effects of oil sands process-affected waters and naphthenic acids on yellow perch ( Perca flavescens) and Japanese medaka ( Orizias latipes) embryonic development

• Published in: Chemosphere (Oxford) 2007-05, Vol.67 (11), p.2177-2183
• Main Authors: Peters, Lisa E., MacKinnon, M., Van Meer, T., van den Heuvel, M.R., Dixon, D.G.
• Format: Article
• Language: English
• Subjects: Abnormalities, Drug-Induced - pathology; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Carboxylic Acids - toxicity; Deformity; Ecotoxicology, biological effects of pollution; Embryo, Nonmammalian - drug effects; Embryonic Development - drug effects; Environmental Restoration and Remediation; Fresh water ecosystems; Freshwater; Fundamental and applied biological sciences. Psychology; General aspects; Hatch; Larva; Oil sands; Orizias latipes; Oryzias - physiology; Oryzias latipes; Perca flavescens; Perches - physiology; Petroleum - toxicity; Risk Assessment; Sodium naphthenate; Species Specificity; Synecology; Water Pollutants, Chemical - toxicity
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2006.12.034

Syncrude Canada Ltd. is currently developing environmentally acceptable oil sands process-affected water management methods as part of their land reclamation strategy. Surface waters of the “wet landscape” reclamation option characteristically have elevated concentrations of sodium sulphate and naphthenic acids (NAs), with low levels of PAHs. The following experiment compared early-life stage responses of yellow perch ( Perca flavescens) to those of Japanese medaka ( Oryzias latipes) when exposed to Mildred Lake settling basin (MLSB) surface water and a commercial sodium naphthenate (Na-NA) standard. Perch eggs were fertilized and incubated in: 100%, 50%, 20%, 4%, 0.8%, and 0.16% dilutions of MLSB water, as well as 20, 10, 5, 2.5, and 1.25 mg/l solutions of the commercial standard. Medaka embryos were exposed to the same treatments, post-fertilization. Both species demonstrated an increase in the incidence of deformity, and a decrease in length at hatch as NA concentrations increased. MLSB surface water contained higher levels of NAs than the commercial standard, however, showed consistently higher NA threshold effect concentrations for both species. Significant differences between the MLSB water and the Na-NA standard suggest that they contain NA congeners with different toxicity, or other compounds such as PAHs. Species differences in thresholds could be explained by the difference in developmental stage in which the exposures were initiated.