Levels of organochlorine pesticides in corals, fish and molluscs from the Great Barrier Reef

Corals, fish and molluscs were collected from twenty inner marginal shelf reefs of the Great Barrier Reef between September 1976 and June 1977. The reefs sampled were Yonge Reef, Lizard Island, Green Island, Scott Reef, Howie Reef, Ellison Reef, Otter Reef, Britomart Reef, Bramble Reef, Keeper Reef, Wheeler Reef, Davies Reef, Broadhurst Reef, Old Reef, Gould Reef, Bait Reef, Parker Reef, Bushy Island, Masthead Island and Wistari Reef. The distance between the mainland and these reefs ranged from 11 to 93 km. The reefs were located between 26 and 222 km from major river estuaries within sugar cane growing regions of Queensland.

Specimens of two species of fish, Plectropoma maculatum (coral trout) and Scarus fasciatus (surf parrot fish), two scleractinian corals, Fungia sp. (Fungia fungites type) and Acropora sp. (Acropora acuminata type) and one bivalve mollusc, Tridacna crocea were collected from each reef. Fish were collected by spearing and corals and clams were collected on SCUBA. All specimens were wrapped in aluminium foil and frozen immediately on dry ice.

Liver and dorsolateral muscle tissue from the fish, subsamples of homogenised clams and ground corals were used for analyses. Samples were extracted using 1:1 by volume hexane/acetone. Part of the extract from each sample was used for gravimetric lipid determination. The remainder was cleaned up using gel permeation chromatography prior to pesticide residue determination using gas-liquid chromatography.

A selection of samples was subjected to a micro scale alkali dehydrochlorination derivatisation procedure for confirmation of lindane.