Caribbean coral reefs 'could vanish in 20 years'

Data from more than 35,000 surveys suggests that habitats have declined by more than 50% since the 1970s.

The report's authors believe that over-fishing and disease is mainly to blame.

They say the trend could continue if nothing is done, but with protection the reefs could bounce back.

http://www.bbc.com/news/science-environment-28113331