Underwater wonder of the Spratly Islands under threat

The Spratly Islands are an area of biological wonder -- an archipelago of atolls and reefs that support 600 coral species and 6,000 fish species -- but they are under threat from large-scale land reclamation in the contested waters of the South China Sea. These photos were taken by ecologist Greg Asner at Swallow Reef in the southeast of the archipelago.