POLYCYCLIC AROMATIC HYDROCARBONS BIOACCUMULATION AND BIOTRANSFORMATION PRODUCTS IN TROUT EXPOSED THROUGH FOOD PELLETS

Abstract

Polycyclic aromatic hydrocarbons (PAHs) were previously measured in whole small finfish (< 30 cm) or in the internal organs relative to the rest of tissues, as well as in muscle, liver, and gonads of larger finfish, collected offshore in the Northwest Atlantic. Alkylated naphthalenes (NA) were more abundant than phenanthrenes (PA), while fluoranthene (FL), pyrene (PY), and chrysene (CH) were also detected in some cases. Bioaccumulation pointed to uptake by respiration and, probably by a dietary contribution, especially for benthic species. Therefore, speckled trout were exposed to PA, FL, and PY through food and the parent PAH and their respective metabolites were analyzed. Trout maintained at 10°C were fed daily for 10 weeks with pellets spiked with 0.33–0.38 μg of each PAH per g fish. Muscle, internal organs, and bile of fish were analyzed by HPLC every 2 weeks, for up to 14 weeks. The concentration of PA was always higher than that of FL. No phase I or phase II metabolites were detected for either compound, even in the bile. Concentrations and total tissue burdens were higher in the internal organs than in the muscle for PA and FL. The highest levels of PA equivalent to 5 days' feeding were present in internal organs on week 10. Levels of PY were lower than levels of FL in internal organs and muscle. The amounts of PY-glucuronide in whole gall bladder bile were higher than amounts of PY in any whole compartment. PY-glucuronide was also detected in internal organs. Comparison will be made to a short-term exposure of winter flounder to 5 μg/g of the same three PAHs.

Keywords:

• bioaccumulation
• biotransformation
• fluoranthene
• metabolites
• phenanthrene
• pyrene
• trout

Acknowledgments

The authors thank the Nova Scotia Department of Agriculture and Fisheries, and in particular Mike McNeil, for supplying the fish. They also acknowledge funding by the Department of Fisheries and Oceans, Maritimes Region. Funding for sensitive instrumentation is required to increase our capability to respond to the goal of Canada's Oceans Strategy: “to ensure healthy, safe and prosperous oceans for the benefit of current and future generations of Canadians.”

Notes

*Std: standard deviation, Cv: coefficient of variation = (std × 100)/mean.