Hong Kong is situated just south of the Tropic of Cancer on the southeastern coast of China (Fig. 1). Due to the influence of the Pearl River, Hong Kong waters can be roughly divided into an estu- arine zone in the west, a transitional zone in the middle and an oceanic zone in the east (Morton and Morton, 1983). Scleractinian corals are common in the protected bays of the oceanic zone. Although corals do not build consolidated reefs in Hong Kong, in some locations they develop into shallow fringing coral communi- ties with up to 2 m thick calcium carbonate substrate overlying volcanic bedrock (Hodgson and Yau, 1997; Ang et al., 2004; Chan et al., 2005).