Mass bleaching drains life from Australian reef

Alarming levels of coral bleaching have been recorded off Australia's western coast, scientists said Wednesday, turning huge chunks of a celebrated reef system a sickly dull white. 

A months-long marine heatwave had damaged the sprawling Ningaloo Reef, part of a world heritage-listed marine park renowned for vibrant corals and migrating whale sharks. Although environment officials were still verifying the scale of damage, it was on track to be the region's worst mass-bleaching event in years. 

According to a scientist, the unfolding mass bleaching looked to be the worst since 2011. Bleaching occurs when warm waters trigger a biological response forcing coral to expel the colorful algae embedded in their tissues.