Physiological disturbances in juvenile sockeye salmon (Oncorhynchus nerka) exposed to the water-soluble fraction of diluted bitumen
| Autor: | Christopher J. Kennedy, Heather L. Osachoff, Feng Lin |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Health
Toxicology and Mutagenesis 010501 environmental sciences Aquatic Science 01 natural sciences 03 medical and health sciences Animal science Salmon Cytochrome P-450 CYP1A1 Juvenile Animals Oil and Gas Fields Listonella Ecosystem 030304 developmental biology 0105 earth and related environmental sciences 0303 health sciences biology British Columbia Dose-Response Relationship Drug Chemistry Dilbit biology.organism_classification Hydrocarbons Bioavailability Plasma osmolality Liver Solubility Toxicity Osmoregulation Oncorhynchus Water Pollutants Chemical |
| Zdroj: | Aquatic toxicology (Amsterdam, Netherlands). 220 |
| ISSN: | 1879-1514 |
| Popis: | Current and proposed transcontinental pipelines for the transport of diluted bitumen (dilbit) from the Canadian oil sands traverse the coastal watersheds of British Columbia, habitat essential to Pacific salmonids. To determine the potential risks posed to these keystone species, juvenile sockeye (Oncorhynchus nerka; 1+ parr) were acutely (24–96 h) or subchronically (21–42 d) exposed to 4 concentrations of the water-soluble fraction (WSF) of unweathered Cold Lake Blend dilbit (initial total PAC concentrations: 0, 13.7, 34.7 and 124.5 μg/L) in a flow-through system. Dilbit effects on iono-osmoregulation, the physiological stress response, and the immune system were assessed by both biochemical and functional assays. Hydrocarbon bioavailability was evidenced by a significant induction of liver ethoxyresorufin-O-deethylase (EROD) activity in exposed fish. Acute and subchronic exposure significantly reduced gill Na+-K+-ATPase activity and resulted in lower plasma osmolality, Cl−, and Na+ concentrations. Acute exposure to dilbit resulted in a classic physiological stress response, however at 21 d of exposure, plasma cortisol remained elevated while other measured parameters had returned to baseline values. A compromised immune system was demonstrated by a 29.5 % higher mortality in fish challenged with Vibrio (Listonella) anguillarum following dilbit exposure compared to unexposed controls. Exposure of juvenile salmonids to the WSF of dilbit (at TPAC concentrations at the ppb level) resulted in sublethal effects that included a classic physiological stress response, and alterations in iono-osmoregulatory homeostasis and immunological performance. |
| Databáze: | OpenAIRE |
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