“The Great Barrier Reef, Nature’s pinnacle of achievement in the ocean realm is the embodiment of wilderness, of remoteness – a place of endless beauty that has endured when so many other places on Earth, cherished by generations past, no longer engender strong emotions or else have been altered beyond all recognition.” J.E.N. Vernon
The Great Barrier Reef is the world’s biggest single structure made by living organisms covering an area of 348,000 square kilometres. It is home to 400 types of coral, 1500 species of fish and 4000 types of mollusc. Due to its significance, the entire ecosystem was inscribed on the World Heritage list in 1981. However, growing threats from climate change, pollution and other anthropogenic activities mean that this iconic marine site may soon be added to the List of World Heritage in Danger.
According to the Great Barrier Reef Marine Park Authority, the greatest threat to the Great Barrier Reef is climate change. As a result of elevated ocean temperatures, coral bleaching events (loss of zooxanthellae in warmer-than-normal conditions) may appear annually. Whenever bleaching occurs, susceptibility for disease also increases, which can lead to detrimental ecological effects for reef communities.
90% of the pollution comes from increased run-off of agricultural sediments, nutrients and chemicals, including fertilizers, herbicides and pesticides, and from mining (discharge of nitrate-laden water). The problem of pollution is coupled with the loss of coastal wetlands which act as a natural filter for toxins and help deposit sediment.
With 12 large ports in the Great Barrier Reef World Heritage Area, the continuous passage of ships to and from the ports can damage the area through groundings, collisions, introduction of invasive marine pests, oil and chemical spills, waste disposal and anchor damage. In April 2010, a large coal-carrier ran aground releasing approximately four tonnes of fuel oil. The subsequent impact assessment report noted that the oil spill caused “extensive and severe physical damage to and destruction of the shoal habitats and considerable contamination by antifouling paint”. Future port developments are also major concern as the dredging of seabed can have a substantial negative impact on seagrass, soft corals, macroinvertebrates, turtles, dugongs and other megafauna, while coral disease can double in areas close to dredging activity.
Joint US-Australian military exercises are regularly being carried out at Shoalwater Bay, which is also a noted dugong habitat and is part of the Great Barrier Reef Marine Park. In 2013, a US Navy training exercise went wrong and an inert and an unexploded ordinance was dropped inside the Great Barrier Reef area off the coast of Queensland. The two ordinance was later retrieved by the US Navy.
This year, Australia submitted a 35-year action plan to UNESCO describing how it would address these threats, which will be discussed at the World Heritage Committee meeting in Bonn next month.
J.E.N. Vernon (2008) A Reef In Time
Image: Courtesy of AirPano