Polycyclic aromatic hydrocarbons in harp seals (Phoca groenlandica) from the Northwest Atlantic

There is virtually no information available on concentrations of polycyclic aromatic hydrocarbons (PAH) in seals from any of the world's oceans. The largest harp seal population in the world is found in Canadian waters of the Northwest Atlantic. Samples of muscle tissue obtained from twenty eight harp seals ranging in age from foetuses to animals 22 years old were analyzed for total PAH and lipid content. Concentrations were determined in terms of crude oil and chrysene equivalents in line with recommendations of the International Oceanographic Commission. Overall, relatively low concentrations were found, the highest values being less than 1 ppm (microgram/g) in terms of chrysene equivalents and 4 ppm (microgram/g) in terms of petroleum hydrocarbon equivalents. The lowest concentrations were observed in fetal tissue. There was no evidence of bioaccumulation with age, the concentrations in juvenile seals (1-5 years) being higher than concentrations in older animals (6-20 years). There was also no correlation between PAH concentration and fat content. There is a possibility that the animals having elevated levels of PAH are from the Gulf of St. Lawrence herd, indicating the importance of obtaining more information on PAH levels in marine mammals and other organisms from this and similar regionally contaminated seas.