Zombie Corals: Ghost Town of Dead Corals in the Pacific is Coming Back to Life

An underwater graveyard of dead corals in the Pacific is slowly coming back to life, scientists found.

Just a year ago, scientists examined the coral reefs in Kiritimati, a remote island in the Pacific. What used to be a stunning site had become an underwater ghost town: 85 percent of the coral was dead and 10 percent was sick because of coral bleached. Only about 5 percent of them were alive.

But after returning this November, the same group of scientists found that 6 to 7 percent of the coral is now alive. Many of the fish that used to rely on coral reefs have come back, and there are "coral babies" settling in.

"We left with a sense of dread and came back with a renewed purpose because there are some corals that literally came back from the brink," Kim Cobb, a climate scientist at Georgia Tech who returned from the expedition earlier, told the Associated Press. "It's the best we could have hoped for."

Coral bleaching affects not only the coral community but the entire ecosystem as well. When water temperatures rise, corals release the symbiotic algae that dwell inside them. The algae provide the nutrients that create the bright colors in the corals, and without them, the corals turn bone white. If temperatures continue to rise, the coral will eventually die.

According to scientists, oceans are currently experiencing the longest stretch of coral bleaching on record, which is driven mostly by El Niño - the natural occasional warming of the Pacific that changes the weather globally - and exacerbated by man-made global warming. The Kiritimati coral reefs are among the most severely affected coral spots in the world.

"But despite this mass mortality, there are a few small signs of hope," Julia Baum, coral reef scientist at the University of Victoria, said in the same statement. "It's clear that coral reefs have great resilience and the coral here is trying to recover."

The Kiritimati coral reefs are not the only ones that have shown strong signs of recovery. Scott reef off Western Australia has revived almost half of its original reef 12 years after the 1998 El Niño had damaged the region. The Coral Castles Reef, which had been pronounced dead in 2003, was found to be flourishing again.