Coral Reefs Still In Danger But Demise Not Inevitable
May 10, 2013

Coral Reefs Still In Danger, But Not Doomed

April Flowers for - Your Universe Online

Although scientists agree that coral reefs are in decline, a new study demonstrates that the collapse of such reefs can still be avoided with a combination of local and global action.

"People benefit by reefs' having a complex structure — a little like a Manhattan skyline, but underwater," said Peter Mumby of The University of Queensland. "Structurally complex reefs provide nooks and crannies for thousands of species and provide the habitat needed to sustain productive reef fisheries. They're also great fun to visit as a snorkeler or diver. If we carry on the way we have been, the ability of reefs to provide benefits to people will seriously decline."

The researchers devoted two years to developing a computer model for predicting the reefs´ future. The model describes how reefs work, building on hundreds of studies conducted over the last four decades. Their reef model was combined with existing climate models to make predictions about the balance of forces that will allow reefs to continue growing their complex calcium carbonate structures, and the forces — such as hurricanes and erosion — that will shrink and damage them.

Mumby said that the ideal goal would be a carbonate budget that remains in the black for the next hundred years at least. The computer model shows that such a future is possible, but only with effective local protection and assertive action against greenhouse gases.

"Business as usual isn't going to cut it," he said. "The good news is that it does seem possible to maintain reefs — we just have to be serious about doing something. It also means that local reef management — efforts to curb pollution and overfishing — are absolutely justified. Some have claimed that the climate change problem is so great that local management is futile. We show that this viewpoint is wrongheaded."

The team also stresses the importance of preserving coral reef function — such as the provision of habitats for fish and the provision of natural breakwater systems to reduce the size of waves reaching the shore — in addition to reef diversity. Hundreds of millions of people depend directly on well functioning reefs for their food, livelihoods and even building materials.

"If it becomes increasingly difficult for people in the tropics to make their living on coral reefs, then this may well increase poverty," said Emma Kennedy, postgraduate researcher at the Marine Spatial Ecology Lab.

The findings of this study were published in a recent issue of Current Biology.