China's survey of the South China Sea has estimated 93 million pieces of debris, raising global concerns about environmental impact and territorial disputes.

An estimated 93 million pieces of debris could be floating on the surface of the South China Sea, based on data collected by China in a projection of its marine monitoring and remote sensing prowess. Using technologies such as fixed-ship monitoring, underway surveys and satellite remote sensing, marine scientists and ecologists audited 26 spots in the central and southern parts of the disputed waters. In a report released this month, Beijing’s Ministry of Ecology and Environment said it...