The influence of water temperature on induced liver EROD activity in Atlantic cod ( Gadus morhua) exposed to crude oil and oil dispersants

• Published in: Ecotoxicology and environmental safety Vol. 74; no. 4; pp. 904 - 910
• Main Authors: Lyons, M.C., Wong, D.K.H., Mulder, I., Lee, K., Burridge, L.E.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01-05-2011; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Applied ecology; Atlantic cod; Atlantic Ocean; Biological and medical sciences; Chemical dispersants; cod (fish); Control equipment; Crude oil; Cytochrome P-450 CYP1A1 - metabolism; Dispersants; Dispersion; Ecotoxicology, biological effects of pollution; enzyme activity; Enzyme Induction - drug effects; Enzymes; EROD; Exposure; Fundamental and applied biological sciences. Psychology; Gadus morhua; Gadus morhua - metabolism; General aspects; Lipids - analysis; Lipids - toxicity; liver; Liver - drug effects; Liver - enzymology; Liver - metabolism; Marine; Oil; oils; Petroleum - analysis; Petroleum - toxicity; physiology; Polyallylamine hydrochloride; polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - analysis; Polycyclic Aromatic Hydrocarbons - metabolism; Polycyclic Aromatic Hydrocarbons - toxicity; risk; risk assessment; Sea water ecosystems; Seawater - chemistry; Synecology; Temperature; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism; Water Pollutants, Chemical - toxicity; Water temperature; MED; A, Atlantic; Atlantic cod; EROD; Temperature; Oil; Chemical dispersants; Ecotoxicology; Enzyme; Toxicity; Liver; Environmental factor; Dispersant; Marine environment; Aquatic environment; Vertebrata; Crude oil; Pisces; Environment; Gadus morhua
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2010.12.013

Juvenile Atlantic cod were exposed to either the water-accommodated fraction (WAF) or the chemically enhanced water-accommodated fraction (CEWAF) of Mediterranean South American (MESA), a medium grade crude oil at three different temperatures. Two concentrations of each mixture were tested, 0.2% and 1.0% (v/v) at 2, 7 and 10
°C. Corexit 9500 was the chemical dispersant tested. The liver enzyme ethoxyresorufin-
O-deethylase (EROD) was measured during a 72-h exposure. The WAF of oil had significant (
P<0.05) effect on enzyme activity compared to controls at only one sampling time: 48
h at 10
°C. Exposure of CEWAF of oil resulted in significantly (
P<0.05) elevated EROD activity compared to controls. The level of EROD induction was temperature related with higher induction being observed in cod exposed to CEWAF at higher temperatures. Total polycyclic aromatic hydrocarbon (PAH) concentrations in exposure water were significantly higher in chemically dispersed mixtures. While PAH concentrations were lower in the 2
°C water compared to 7 or 10
°C (8.7 vs 11.9
μg
mL
−1), the level of EROD induction was approximately 9 and 12 times lower at 2
°C compared to 7 or 10
°C, respectively, suggesting the metabolic rate of the cod plays a role in the enzyme response. These data suggest the risk of negative impacts associated with exposure to chemically dispersed oil may be affected by water temperature and that risk assessment of potential effects of WAF or CEWAF should consider the effects of water temperature on the physiology of the fish as well as the effectiveness of dispersants.