Aromatic hydrocarbons in seawater, sediments and clams from Green Island, Great Barier Reef, Australia

Abstract

Seawater, sediment and clams from the coral reef around Green Island have been analysed for polycyclic aromatic hydrocarbons using high-performance liquid chromatography with fluorescence for detection and identification of individual compounds. Green Island is of interest because it is a tourist resort and the most visited coral island of the Great Barrier Reef.

The concentration ranges of some of the polycyclic aromatic hydrocarbons detected were: in water (ng I^-1), pyrene 53-< 1, anthracene 25-<1, benzo(a)pyrene 6-<0.2; in sediments (µg kg^-1 dry wt), pyrene 15- < 1, anthracene, 1.0-<0.06, benzo(a)pyrene 4.3- <0.004; in clams (pg kg^-1 wet wt), pyrene <0.03, anthracene < 0.05, benzo(a)pyrene <0.004.

Only sediments near power-boat moorings were found to contain low but measurable amounts of several different polycyclic aromatic hydrocarbons in contrast to the baseline amounts found at ihe other locations. The presence of several polycyclic aromatic hydrocarbons at measurable levels strongly suggests that their origin was from fuel spillage or exhaust emissions.

The fluorescent intensity of organic-solvent extracts of seawater which had also been analysed for polycyclic aromatic hydrocarbons was measured using either fixed-wavelength or synchronous-wavelength excitation. For both types of excitation, fluorescent intensities could be used to indicate the presence of small amounts of polycylic aromatic hydrocarbons which were just above the limit of detection using high-performance liquid chromatography.