The impacts of guano and rock phosphate mining
More than 300 coral cays and 600 continental islands lie within the GBRWHA and they form distinctive environments of the Great Barrier Reef. The evolution and geomorphology of cays and continental islands in the Great Barrier Reef have been discussed by Hopley (1982), who acknowledged that some of those cays and islands have been significantly modified by human activity since European settlement. Indeed, the transformation of some island landscapes probably represents the most comprehensive human impact on the landscape of the Great Barrier Reef, at least at the local scale (Flood, 1977, 1984; Stoddart et al., 1978). Examples that illustrate the extent of that transformation, and which are discussed in this chapter, include the changes wrought by guano miners at Lady Elliot Islands, Raine and North West Islands, and the removal of rock phosphate from Holbourne Island. First, however, the earliest recorded European impact on an island in the Great Barrier Reef is described: the construction of the navigation beacon at Raine Island, in 1844, using phosphatic sandstone quarried at the island. Next, the various guano and rock phosphate mining operations in the Great Barrier Reef are considered, together with their impacts on island landscapes.