Report: Coral reef bleaching event largest ever
New data from the National Oceanic and Atmospheric Administration has scientists ringing alarm bells about the health of the world's oceans. Seventy-seven percent of the world's coral reefs have experienced "bleaching-level heat stress" over the last 22 months. Derek Manzello, coordinator of NOAA's Coral Reef Watch program, joins CBS News to dive deeper into the research.