The Great Barrier Reef in Australia. Pixabay
Beset by severe heat throughout the Australian summer, the Great Barrier Reef is undergoing its fifth mass bleaching in eight years.
Warm waters cause corals to expel the colorful algae that live inside them, turning reefs white. Reefs can recover if waters cool, but extended periods of heat may prove lethal. Aerial surveys of the Great Barrier Reef show widespread bleaching in shallow waters, said Roger Beeden, chief scientist with the Great Barrier Reef Marine Park Authority.
NOAA
The reef is one of many around the world to undergo mass bleaching over the past year. With climate change, oceans are overheating, and El Niño is now amplifying the warming trend. In February, the ocean surface measured 69.91 degrees F (21.06 degrees C) on average worldwide, a record high, according to the EU Copernicus Climate Change Service.
Officials from NOAA warn that the world’s reefs are on the verge of their worst-ever mass bleaching. “Climate change is the greatest threat to the Great Barrier Reef, and coral reefs globally,” Beeden said.
Still, while the Great Barrier Reef is highly vulnerable to severe heat, not all areas have been affected the mass bleaching, and those that have may bounce back, Beeden said. “The Reef has demonstrated its capacity to recover from previous coral bleaching events, severe tropical cyclones, and crown-of-thorns starfish outbreaks.”
