Chapter Twenty-One Mud threat to the Great Barrier Reef of Australia

Abstract

Publisher Summary This chapter describes the mud threat to the Great Barrier Reef of Australia. The Cairns coast of the Great Barrier Reef of Australia has been influenced by human-induced erosion. Much of the forest and natural coastal vegetation and wetlands have been modified to permit urban, port, industrial, and agricultural development. The coastal rivers have become drains bringing eroded sediment to settle as mud in the estuaries, in the coastal shallows and on the inshore reefs. Additional mud from dredging the port of Cairns is dumped in coastal waters. The resulting addition of nutrient-rich mud to the sea is considered by some to be one of the most threatening impacts on coastal reefs of the Great Barrier Reef system. Long-term effects of low-level sedimentation on coral reefs include tissue lesions and diseases, decreased calcification, decreased net productivity and growth, and shifts in abundances and species composition. The mangroves have responded naturally in unison, with geological and geomorphic changes, to help stabilize mud banks. A delicate balance has been maintained, allowing the offshore creation of the Great Barrier Reef.