Surviving reef 'more resilient to heat'

SYDNEY - Corals on Australia's Great Barrier Reef that survived bleaching from rising sea temperatures were more resistant to another bout of hot conditions the following year, scientists said on Tuesday, a "silver lining" for the embattled ecosystem.

The 2,300-kilometer-long UNESCO World Heritage-listed reef off Australia's northeastern coast was hit by back-to-back bleaching in 2016 and 2017.

Bleaching occurs when abnormal environmental conditions, such as warmer sea temperatures, cause corals to expel tiny photosynthetic algae, draining them of their color.