Coral reef bleaching near record level

LONDON — Nearly two-thirds of the world's coral reefs have been subjected to heat stress bad enough to trigger bleaching over the past year, the leading agency monitoring coral reefs said on Thursday.

The United States' National Oceanic and Atmospheric Administration, or NOAA, announced last month that the world's coral reefs were in the throes of a fourth mass bleaching event, as climate change combined with an El Nino climate pattern has pushed ocean temperatures to record highs.

Now, the agency reports some 60.5 percent of the world's reef areas have been affected and that number is still rising.