Executive Summary Coral reefs in Australia form a large ancient habitat for living things, thus making the region one of the fascinating sites across the world. The Australian and the Queensland land government collaborate in managing the Great Barrier Reef. The Great Barrier Reef forms the world’s largest coral reef ecology. The large size of the reef calls required great responsibility in a bid to manage and ensure the sustainability of the ecosystem. This paper discusses the array of activities by human beings that are threatening the sustainability of the Great Barrier Reef. Apparently, the Great Barrier Reef has experienced threats from a plethora of human activities, economic explosion, and climate change. A current report by the Great Reef Strategic Assessment (GRSA) conducted in 2014 affirms that even though coral reefs maintain their resilience as one of the most preserved marine ecosystems across the globe, there has been a superfluity of human activities, thus causing the decline of the reefs (Pyers, 2011). Consequently, the reef zone has encountered extreme effects of cyclones and floods, which compromise the capacity of the ecosystem to counter and cope with these alterations and other human interferences. Poor water quality mounting from land runoff, coastal construction, impacts of exploration, and unregulated fishing pose threats to the sustainability of the Great Barrier Reef ecosystem. This pressure surpasses the chances of the reef to recover from the ever-emerging disturbances. This paper concludes by identifying that further threats will decline the outlook of the reef zone and worsen the situation coupled with endangering the extinction of marine life, causing an imbalance in the ecosystem, and triggering global warming. Introduction The Australian coral reefs provide one of the most valued natural features in the world. Following the ecological importance of the coral reefs, under the management of Australia and Queensland government, zoning of the coral area was done along the coastline, thus creating the Great Barrier Reef. The Great Barrier Reef covers approximately 2300 kilometers along the coastline with an enormous stretch of coral reefs. The reef zone provides habitat for a large array of fish species, seabirds, coral, sea vegetation, and turtles, among other wildlife animals. Apart from marine life, the coral reef zone provides unique scenery, which attracts huge numbers of tourists, agriculturists, and a host of commercial activities. Following the overwhelming environmental sustainability challenges and the ecological significance of the reef area, the United Nations Educational and Cultural Organization (UNESCO) declared the Great Barrier Reef as a World Heritage Center in 1981 (Veron, 2008). This move was arrived at in an effort to regulate the ever-increasing human activities threatening the outlook and sustainability of the coral reefs. This paper will show that currently, several natural and human activities endanger the extinction of coral reefs in Australia, and if drastic measures to restore sustainability are not taken, the current situation of poor water quality, coral decline, climate change, and wildlife extinction