Study may help scientists identify which coral reefs can be saved

With the world's oceans on the verge of what may be a year of significant coral bleaching, researchers have devised a simple way of predicting which reefs stand the best chance of recovery from a climate-triggered bleaching event.

The study, led by Australian marine scientists Nicholas Graham, Aaron MacNeil, and Shaun Wilson, come at a time when concerns are mounting among some reef specialists that a persistent buildup of warm surface waters in the western tropical Pacific could spark a significant bleaching event approaching the scale not seen since the late 1990s – the likes of which no one had seen before.

Reefs worldwide host some 25 percent of all marine species and serve as protective nurseries for newborn fish and other forms of marine life. They also serve as a first line of defense from storm surge for coastal communities and through fishing provide the main source of protein in the diets of more than 500 million people.

Coral reefs grow out of a tightly knit partnership between clear organisms known as coral polyps and tiny algae that inhabit cells that line the polyps' digestive system. The polyps protect the algae and provide them with the carbon dioxide they need for photosynthesis, as well as with other nutrients the polyps eject as waste. The algae provide organic compounds polyps need to survive and to produce calcium carbonate, which builds up a reef's structure. The algae are the flashy dressers, lending the polyps their unique colors.

By identifying two simple factors that contribute to a reef's recovery and appear to be powerful predictors of which reefs are most likely to recover, the researchers have accomplished something "extraordinarily important," she says. These are simple metrics that even the most cash-strapped conservation managers can apply.

Full story here.