abstract:The Gold Coast Broadwater, also known as Southport Broadwater and Gold Coast Harbour, is a large shallow estuary of water reaching from the locality of Southport to the southern section of the World Heritage Listed Moreton Bay along the eastern coast of Australia. Separated from the ocean by the a thin strip of land called Stradbroke Island, the original body of water was a lagoon created from water deposited from the Nerang River.