The Great Barrier Reef is an extensive ecosystem located off the coast of Queensland in northeastern Australia. It is made up largely of a 2,300-km long colony of coral, which taken as a whole organism, is considered the largest living structure on Earth, comprising many ecosystems: thousands of reefs, hundreds of islands, structures built of hard or soft coral of unimaginable variety. It is home to countless species of colorful fish, mollusks, starfish, turtles, dolphins, and even sharks.
This massive ecosystem, so huge and so distinct it could be seen from space, is in serious ecological trouble. Climate change has caused a warming of seawater, which has thrown the delicate ecosystem out of balance, and much of the reef has been recently found to be dead, a result of the temperature change within this very delicate ecosystem. Signs of an even greater die-off in the future have been noted, particularly a bleaching of large sections of coral reef.
“We didn’t expect to see this level of destruction to the Great Barrier Reef for another 30 years,” Terry P. Hughes, director of an Australian-government-sponsored center focusing on coral reef studies at James Cook University in Australia said, in an interview with the New York Times. “In the north, I saw hundreds of reefs — literally two-thirds of the reefs were dying and are now dead,” he added.
Hughes is the lead author of a recent paper on the reef that was published earlier this month as a cover article for the journal Nature.
Reef scientists are now certain that human activity is responsible for the threat to the Great Barrier Reef.
Globally, the ocean has warmed more than 1.5 degrees since the latest 19th century, enough to start causing mass extinctions and habitat destruction. This seemingly small difference leads to “bleaching” of coral reefs, a precursor to death of a reef and extinction of its unique species. Besides the threat to biological diversity, many people make their living from the wealth of edible fish and sea creatures that make their homes in the nooks and crannies of the reef. In poorer countries, the harvest of small edible creatures from the reef is the main source of protein for many small fishing families.
Scientists are keeping a close watch on this delicate system, but ultimately the cooperation of many nations and interests will be required to tip this delicate balance in favor of ecological survival.