Divers turn conservationists as corals bleach worldwide

Koh Tao, Thailand - A diver glides over an expanse of bone-white coral branches, recording the fish that dart between the ghostly arms extending from the sea floor off the Thai island of Koh Tao.

Nannalin Pornprasertsom is one of a growing number of scuba divers learning conservation and citizen science techniques as coral reefs experience a fourth global bleaching event.

After a two-week course in Koh Tao,