Healthy coral reefs are famous for color. Their vibrant oranges and blues dazzle divers. But that brilliance is fading in Australia’s Great Barrier Reef.

Hotter ocean temperatures are causing coral to eject the algae it hosts within its body – algae it needs for food and color. It’s a process called coral bleaching.

There have been multiple mass bleaching events in recent decades. Over time, some of the damage can heal. But as the oceans continue to warm, new bleaching events are now occurring before the coral has a chance to recover.

After the recent El Niño, more than 90 percent of the 1,400-mile long reef is bleaching. Terry Hughes of James Cook University in Australia says the worst damage is in the northern, most pristine section.

Hughes: “It’s a real tragedy to lose the best part of the Great Barrier Reef.”

More than color is at stake. The Great Barrier Reef supports 30 kinds of whales and dolphins, and 1,500 kinds of fish.

So what can be done to protect this precious ecosystem?

Hughes: “The only way to avoid bleaching is to deal urgently with global greenhouse-gas emissions.”

The future of the Great Barrier Reef depends on it.

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Reporting credit: ChavoBart Digital Media.
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Daisy Simmons

Daisy Simmons is a freelance writer and editor with more than 15 years of experience in research-driven storytelling. In addition to contributing to Yale Climate Connections since early 2016, she also...