Mangroves are an inter-tidal habitat of particular interest in studies of heavy metal pollution. They are extensive in the subtropics and tropics, can act as sinks for heavy metals (Harbison, 1986) and are well known for the high sulphide content and reducing properties of
their sediments (Hart, 1959, 1962; Hesse, 1961; Hutchings & Saenger, 1987). Mangroves are often at risk from heavy metal pollution due to a range of anthropogenic, metal producing activities, ranging from shipping and port development and manufacturing to sewage and storm water discharge, all of which tend to be concentrated in coastal and estuarine regions where mangroves are common. The objectives of the current study were to investigate AVS values and their spatial variation in a subtropical mangrove forest, and, in a preliminary way, use these to assess the potential availability of sediment heavy metal burdens to mangrove fauna and flora. Temporal variability was avoided by collecting samples during a single low tide period.