Australia's famed Great Barrier Reef is suffering one of the most severe coral bleaching events on record, leaving scientists fearful for its survival as the impact of climate change worsens. For 33 years marine biologist Anne Hoggett has lived and worked on Lizard Island, a small slice of tropical paradise off Australia's northeast tip. She affectionately dubs it "Blizzard Island". The only relief from the wind and teeming showers is in the powder blue waters, where sea turtles and tiger sharks rove along the Great Barrier Reef. As Hoggett snorkels, schools of fish swim gracefully, feeding on the coral or darting between it. Some are as small as her little finger, others the color of fire. But thanks to climate change, it is becoming a watery graveyard of bleached reef. "We don't know yet if they've already sustained too much damage to recover or not," said Hoggett. The world is currently experiencing its second major coral bleaching event in 10 years, the US National Oceanic and Atmospheric Administration (NOAA) announced Monday. Coral bleaching occurs when water temperatures rise more than one degree Celsius (33.8 degrees Fahrenheit). "As the world's oceans continue to warm, coral bleaching is becoming more frequent and severe," said NOAA's Derek Manzello. In a bid to survive, the coral expels microscopic algae, known as zooxanthellae, which it needs to live. If high temperatures persist, the coral eventually evicts most of the zooxanthellae, turns white, and dies. Since February, ocean temperatures around Lizard Island have been up to two degrees Celsius warmer than the average. Hoggett estimates about 80 percent of the coral is already dead. Often dubbed the world's largest living structure, the Great Barrier Reef is a 2,300-kilometer (1,400-mile) long expanse housing a stunning array of biodiversity, including more than 600 types of coral and 1,625 fish species. It is... |