China's land reclamation in the South China Sea has raised geopolitical concerns (see go.nature.com/tmrpih). It is also destroying coral reefs on a large scale — together with their fragile ecosystems.

This loss of reef habitat is estimated from high-resolution satellite imagery to be about 1,400 hectares so far in the Spratly Islands (http://amti.csis.org/island-tracker). The reefs are among the most biologically diverse on the planet. They are home to threatened turtle and bird species, a crucial stopover for migratory birds, and a source of larvae for the South China Sea's overexploited coastal fisheries. Further dredging will kill nearby sediment-dwelling communities and sea-grass nursery habitats that take up carbon.

The global scientific, conservation and legal communities must unite to halt this destruction. Reef loss can be publicly monitored with Google Earth imagery and tools, enabling international governing bodies to enforce China's obligations under international law to protect and sustainably manage their reefs (see go.nature.com/wdzf9k). And funding should be fast-tracked for the proposed protective Spratly Islands Marine Peace Park (J. W. McManus et al. Ocean Dev. Int. Law 41, 270–280; 2010).