In December 1993 a study of contaminated sites at Casey Station, Wilkes Land, Antarctica, was undertaken. The preliminary assessment of these contaminated sites is presented here. A register of contaminated sites for Casey Station was developed, based on a survey of past Antarctic expeditioners, relevant literature, and in-house reports relating to site usage and history. On this basis a sampling strategy was devised for the highest priority, potentially contaminated sites at Casey Station. Samples were collected from the refuse disposal site (tip site) at Thala Valley and the mechanical workshop/powerhouse areas of ‘Old’ Casey. The results indicated that copper, lead, and zinc were leaching from the tip site into adjacent Brown Bay, with ‘hot spots’ of high petroleum hydrocarbon levels. The mechanical workshop/powerhouse area was also shown to be contaminated with petroleum hydrocarbons, polycyclic aromatic hydrocarbons, and metals such as copper, lead, and zinc. Several recommendations were made, including the removal of rubbish mixed with soil at the bottom end of Thala Valley in such a manner as to prevent any further release of contaminants, with subsequent site monitoring to verify effective removal of contaminants to acceptable environmental levels. It was also recommended that further investigations be carried out on the ecosystem of Brown Bay, the large fuel spill site, the upper and lower fuel-storage areas, and the area around the incinerator. There is scope for monitoring the natural breakdown and migration of contaminants at the mechanical workshop/powerhouse site. This should include studies on bioremediation of hydrocarbon-contaminated soils. Mechanisms for arresting surface migration should be investigated in those sites identified. In addition to meeting some of the international obligations of the Protocol on Environmental Protection to the Antarctic Treaty, this work also contributes towards the development of an approach to assessment and management of contaminated sites that is uniquely adapted to the Antarctic environment and could be applied at other Antarctic stations. to the assessment and management of contaminated sites that is uniquely adapted to the Antarctic environment. This approach could be utilised for site assessments at other Antarctic stations.

Deep-sea sharks (mainly dogfish) are a significant by-catch of trawls for the deep-water fish orange roughy (Hoplostethus atlanticus). To test whether the livers of these sharks might be a source of commerically valuable squalene and other lipids, 16 sharks of 8 species were collected from Tasmanian waters at depths of 700-1200 m during research cruise S02/88 of FRV Soela. The sharks were Centroscyrnnus crepidater (longnose velvet dogfish), Centroscyrnnus owstoni (Owston's dogfish), Centroscyrnnus coelolepis (Portuguese dogfish), Deania calcea (shovelnose dogfish), Etmopterus baxteri (Baxter's dogfish), Etmopterus sp. nov. (unnamed dwarf dogfish), Dalatias licha (kitefin or seal shark) and Centrophorus squarnosus (leafscale gulper shark). Squalene content, triacylglycerols, diacylglyceryl ethers, total fatty acids, pristane and other lipids were analysed by capillary gas chromatography and thin-layer chromatography-flame ionization detection. The livers contained high levels of squalene (15-69% by weight), except for the liver of C. squarnosus (I%), which had an unusually high amount of diacylglyceryl ethers (79%). Triacylglycerol and diacylglyceryl ether contents in the livers ranged from 1 to 26% and from 7 to 79% by weight respectively. The C19 isoprenoid alkane pristane was a minor constituent in all samples (0.01-0.56% by weight of liver). The three major esterified fatty acids in all samples were palmitic (16:0), oleic [18: 1 (n - 9)] and eicosa-11-enoic [20: 1 (n - 9)] fatty acids. Polyunsaturated fatty acids were minor constituents. These data indicate that shark livers could provide a profitable by-catch from deep-water trawls, but it is unlikely that shark could form the basis for a target fishery due to their susceptibility to overfishing.

Organic Lake in the Vestfold Hills, Antarctica, is a shallow (7.5 m), meromictic, hypersaline lake that contains a microflora of low species diversity. The lake monimolimnion is anoxic but contains no H2S. Organic Lake has the highest concentrations of dimethyl sulfide (DMS) as yet recorded in a natural aquatic ecosystem. The greatest concentration of DMS in the lake, 97 �g 1-1, occurs just above the oxic-anoxic interface. Its presence coincides with maximal numbers of the alga Dunaliella sp. and maximal numbers of bacteria. Analysis of head space samples from axenic cultures indicates that Dunaliella sp. is not directly involved in DMS production. A bacterial strain that was isolated from Organic Lake and that produced DMS from sulfur-containing amino acids was presumptively identified as a Halomonas sp.

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