The Coral DredgersJohn G. Butcher
When the Queensland Cement and Lime Company was founded in 1914 it faced a fundamental problem. Its factory in Darra was located near its main market in Brisbane, but it had to obtain the calcium carbonate it needed to make cement from a limestone quarry west of Warwick. Because of the great cost of transporting the limestone by rail to Darra QCL wanted to find a much closer source of calcium carbonate. In 1931 the University of Queensland geologist Henry Richards, who had been investigating Moreton Bay's coral reefs, told QCL that Mud Island's reef could supply it with all the calcium carbonate it needed for centuries to come. QCL quickly obtained a licence from the state government to dredge coral at Mud Island. In the mid 1930s it began dredging coral at the island, transporting it up the river to a wharf at Oxley, and trucking it from there to the plant.As the demand for cement skyrocketed after the war QCL found ways to increase the rate at which it extracted coral. It converted an LST into a powerful dredge and a surplus transport ship into a coral carrier. Soon QCL was removing the reef around Mud Island at a rapid rate, leaving a muddy seabed and coral rubble ridges in its place. Needing ever more coral, QCL obtained licences over more and more reefs, most notably at St Helena and Green islands.In 1989 the Ahern government promised to renew QCL's licences at St Helena and Green islands when they came up for renewal in 1991. The Goss government renewed QCL's licence at St Helena but demanded a study of the likely impact of dredging on Green Island, where QCL had yet to dredge. Environmental and community organizations came together to fight QCL's plans at Green Island. For its part, QCL pleaded that Queensland needed the jobs and the cement the Darra plant provided. In 1995 the government came up with a solution: it subsidized an expansion of QCL's plant at Gladstone on condition that QCL exit the bay as soon as possible. The dredging ended in 1997. The muddy seabed and rubble banks remain.