Cyclone Oli deals major blow to French Polynesia's coral reefs

In 2001, I spent a few months on Mo`orea, a sister island of Tahiti. There, I had the good fortune to study coral bleaching as part of a research program with U.C. Berkeley. It was the first time I had gotten to SCUBA on tropical coral reefs, and the experience changed my life. My time in that program is a large part of why I am in oceanography now.

I can remember descending at the beginning of one dive, north of the outer slope. The whole slope down was a riot of color and rough relief, all branching corals, mushroom corals, small and large head corals... It was awesome, in the true sense of the word. There were colorful tiny fish flitting in and out of every small crevice; territorial damselfish watching our dive group sink into the blue waters and rushing out to threaten us should we get too close to their small patch of coral; spotted puffers that seemed unaware of their surroundings as they blimped around in funny, cockeyed loops; surgeonfish swaying gracefully by the wall made up of tiny, slow-growing organisms; and parrotfish hunting about for a good place to scrape their teeth. It was a paradise of color, motion, variety. It was just beautiful.

But a report has just come out about the state of the coral in this very area after a tropical cyclone hit the islands, and it's not pretty. It seems that much of the coral on Mo`orea's outer slopes, especially in the north, have been severely and lastingly damaged. The corals in the area had already been extremely stressed by the outbreak of a particularly effective coral predator, Acanthaster, or the crown-of-thorns starfish. I saw a few of these nasties when I was there, but they really became a problem in 2006, when their population exploded. Corals that had been grazed down before the cyclone were expected to eventually recover, since their skeletons were left intact. But after Oli passed in early February this year, recovery seems too optimistic; the cyclone brought with it winds in excess of 120mph, brutally pummeling the islands and breaking many of the stressed branching corals off at the base. A subsequent algal bloom in the shallower waters have covered up the remains of broken and intact coral skeletons with a thin slimy mat, a further barrier to recovery. Researchers estimate we will know the true impact of this series of events in another 10 years. Until then, we have to wait and see if these beautiful creatures can recolonize.

Here is a good summary article via Science Daily:
Cyclone Oli deals major blow to French Polynesia's coral reefs
The picture here is from Science Daily, and is the before/after shot of a coral monitoring site.