(A) The Great Barrier Reef is the world’s largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over 2,300 km. over an area of approximately 344,400 sq. km.The reef is located in the Coral Sea, off the coast of Queensland, Australia. The Coral Sea is a marginal sea of the South Pacific off the northeast coast of Australia,and classified as an interim Australian bio region.