Concentrations of copper, zinc, cadmium and lead in rabbitfish (Siganus oramin) collected in Victoria Harbour, Hong Kong

The urban area of Hong Kong supports a population of about 4 million people, with an annual production of several hundred million tonnes of untreated domestic and industrial effluent. This causes significant marine pollution problems in Victoria Harbour. Moreover, urban runoff also brings pollutants to Victoria Harbour. This paper presents preliminary data on the concentrations of heavy metals from different parts of the rabbitfish (Siganus oramin) taken from Hung Hom, Wan Chai and the Central Ferry Pier, close to urban and sewage outfalls in Victoria Harbour, from June to September 1983. Metal concentrations in the seawaters and from the gills, viscera, vertebrae and muscle were determined by atomic absorption spectrophotometry. Concentrations of copper, zinc and lead in the muscle were found to be the lowest in the muscle as compared with other parts of the body (cadmium concentrations were similar in muscle and viscera), but concentrations were nevertheless still high (mean±SD, dry weight): 5.7±4.0 ppm for copper, 66.6±31.8 ppm for zinc, 3.3±1.1 ppm for cadmium and 19.1±6.3 ppm for lead. Cadmium and lead concentrations in the rabbitfish samples of this study were significantly higher than those previously reported in fish from the nearby Pearl River estuary.