The ecological effects of naphthenic acids and salts on phytoplankton from the Athabasca oil sands region

• Published in: Aquatic toxicology Vol. 62; no. 1; pp. 11 - 26
• Main Authors: Leung, Sherwin S., MacKinnon, Mike D., Smith, Ralph E.H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 10.01.2003; Elsevier Science
• Subjects: Agnatha. Pisces; Alberta; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Biomass; Canada, Alberta, Fort McMurray, Athabasca R; Canonical ordination; Carboxylic Acids - adverse effects; Chlorophyta - drug effects; Chlorophyta - growth & development; Dose-Response Relationship, Drug; Ecosystem; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Effects of pollution and side effects of pesticides on vertebrates; Fresh Water - chemistry; Freshwater; Fundamental and applied biological sciences. Psychology; naphthenates; naphthenic acid; Naphthenic acids; Oil sands; Petroleum - adverse effects; Phytoplankton; Phytoplankton - drug effects; Phytoplankton - growth & development; Population Dynamics; Salinity; Salts; Water Pollutants, Chemical - adverse effects; Canada; Alberta; North America; America; Canada, Alberta; Canada, Alberta, Athabasca R; Oil sands; Phytoplankton; Canonical ordination; Naphthenic acids; Salinity; Community structure; Aquatic environment; Naphthenic acid; Pond; Plant community; Toxicity; Environmental factor; Water pollution; Biomass; Tar sand
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/S0166-445X(02)00057-7

To better elucidate the ecological effects of naphthenic acids and major ions liberated in oil sands development, the summer-time composition of phytoplankton communities in ten water bodies near Fort McMurray (northeastern Alberta) was studied in 1997. The water bodies varied in degree of process water influence, and in age, size and ancillary chemical characteristics. Community biomass of phytoplankton was not systematically related to naphthenic acid or major ion concentrations, even though the higher naphthenate concentrations exceeded published EC50's for acute effects on several different aquatic species. Chlorophyta were frequently dominant, particularly where naphthenate and major ion concentrations were highest. Canonical Correspondence Analysis (CCA) revealed gradients in taxonomic composition at a finer (genus and species) taxonomic level. Despite the simultaneous and uncontrolled variation of other environmental factors, naphthenate and major ion concentrations (as indexed by conductivity) explained a highly-significant 40% of the variation in taxonomic composition. Systems with naphthenates <6.5 mg l −1 and conductivity <800 ΦS cm −1 were clustered together near the origin of the CCA plots, suggesting little ecological effect at such concentrations. Taxa associated with elevated naphthenate and/or major ion concentrations were derived from six different algal divisions and included many that were identified as tolerant in previous bioassay experiments. Over the range of concentrations encountered (1.5–45 and 100–3000 mg l −1 for naphthenates and ions, respectively), CCA indicated that the ecological effect of major ions appeared to be at least as great as that of naphthenates.