The Great (Dwindling) Barrier Reef Loses Half Its Coral Cover In Under 30 Years

If half the Grand Canyon crumbled to nothing in less than three decades, would we stand up and pay attention? If Teddy and Abe’s heads eroded off Mount Rushmore would we step in to save George and Tom?

Sadly, that’s what is happening to one of the world’s great natural treasures.

A new study released yesterday by the Australian Institute of Marine Science shows that in just the last 27 years, the Great Barrier Reef has lost half of its coral.

Coral reef degradation is unfortunately not a new phenomenon. A 2011 report from the World Resources Institute found that three-quarters of the world’s coral reefs are threatened by increased stress from pollution and climate change. Corals are very sensitive to temperature, but because they are stationary, they cannot migrate to find their prime habitat. So as ocean temperatures warm, the coral organisms die, leaving just the white skeletal structures, a phenomenon known as bleaching.


Yet according to this new study, the degradation is less directly linked to these usual suspects. Just 10 percent of the loss was attributable to bleaching. The study found coastal storms were the leading culprit that caused 48 percent of the damage, and the remaining 42 percent was a result of an exploding population of the crown of thorns starfish that preys on coral.

Don’t mistake these causes for reason to think climate change isn’t responsible. After all, an increase in intensity of coastal storms is undoubtedly a symptom of planetary warming.

Controlling the starfish problem, it turns out, would allow the reef’s degradation — pegged at losses of between four and eight percent of coral cover per year — to reverse. Even at current levels of temperature and acidity, we could see slow coral growth. The starfish problem may be slightly easier to manage than reversing global emissions of greenhouse gasses, but it will require action sure to be unpopular with agricultural interests. As CNN reports:

According to the study, the starfish in its larval stage feeds on plankton, populations of which surge when fertilizer runoff floods the coastal ocean waters with nutrients. So plentiful plankton can lead to swarms of hungry starfish.

The last time the starfish bloomed in 2003, the government spent more than $3 million to try to control the population. No easy feat. But the motivation to succeed may be as great as the Great Barrier Reef itself. In addition to the inherent value of protecting a tremendous natural resource, and the environmental benefits it provides from fish habitat to protection against storm surges, the reef is also a major economic engine in northeast Australia. According to Nick Heath, a spokesman for the World Wildlife Fund Australia, “Sixty thousand jobs in the tourism industry depend on us acting with urgency over the next few years.”


Oddly, the Australian government is also planning coal and natural gas export facilities that would bring a constant stream of ships across the Great Barrier Reef World Heritage Area.

With all these environmental threats and new industrial activity, apparently we’ll have to be content with renaming one of our most spectacular natural wonders the Incredibly Shrinking Barrier Reef.

Michael Conathan is the Director of Ocean Policy at the Center for American Progress