Bioaccumulation of aromatic hydrocarbons from sediments: a dose-response study with flounder (Pseudopleuronectes americanus).

Pseudopleuronectes americanus were chronically exposed to Hibernia crude oil in sediments, for 4 months. Oil was added to sediments at five concentrations between 0.09 and 4.5 mg/g (dry weight) and was 0.10-0.90 mg/g, at the termination of the exposure. Bioaccumulation measured in terms of fluorescence or in terms of the concentration of specific aromatic targets, increased with dosage. Accumulation of hydrocarbons was observed in muscle tissue (0.22 microgram/g, dry weight), when concentration of the sum of 27 polycyclic aromatic compounds (PAC) in sediments was of 0.65 microgram/g (E-50), at the end of the 4-month period. Of the 27 parental and alkylated polycyclic aromatic compounds analyzed, alkylated naphthalenes predominated in muscle (90-100%) and in sediments (30-60%). Bioaccumulation factors were derived for 13 compounds detected in muscle, at the three higher exposures. Liver concentrations (fluorescence) were higher than in muscle, but did not display a noticeable dose-response. Several alkylbenzenes, a C-2 biphenyl and C-4 acenaphthene were also detected in muscle extracts. The development of dose-response relationships for polycyclic aromatic hydrocarbons (PAH) present in sediment, in relation to bioaccumulation in flatfish, is of major interest for evaluating the environmental effects of oil contamination.

Polycyclic aromatic compounds in cod (Gadus morhua) from the Northwest Atlantic and St. Lawrence Estuary.

There is limited information available on levels of polycyclic aromatic hydrocarbons (PAH) in major fish populations including populations from the Northwest Atlantic. The cod (Gadus morhua) stocks off eastern Canada form the basis of one of the world's most important fisheries. Muscle tissues of cod collected from Northwest Atlantic Fisheries Organisation (NAFO) management Divisions 2J, 3K and 3Ps off Newfoundland and Labrador, as well as three contaminated sites in the Gulf of St. Lawrence were analyzed for total polycyclic aromatic (PAC) by fluorimetry. Concentrations were determined in terms of crude oil and chrysene equivalents in line with recommendations of the International Oceanographic Commission. Overall, relatively low concentrations of PAC were found, the highest values generally being below 0.1 microgram/g (dry weight) in terms of chrysene equivalents. Similarly, only trace levels of a few PAH were detected in composite samples analyzed by gas chromatography-mass spectrometry (GC-MS). It is of interest that the highest levels of PAC were found in fish from NAFO Division 3K, while concentrations in fish from the two contiguous zones, 2J and 3Ps, as well as the Gulf of St. Lawrence, were similar. Division 3K is a major fishing zone and it is important to determine if trawler fleets are important sources of hydrocarbons derived from fossil fuels, in this and similar fishing areas of the world's oceans.

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.