Islands built in the open ocean are not new, but recent projects in the South China Sea are causing serious environmental harm. China and others have built artificial islands by using huge amounts of sand, coral, and sediment dredged from reefs. This process covers reefs with sediment, killing coral animals that took centuries to build these structures. The Spratly Islands sit in a marine hotspot with many species. Reefs here support fish and endangered animals like sea turtles and sharks. The damage affects fishing across wide areas beyond the construction sites. Scientists say these reefs will not recover within any human timeframe. Island building also changes water currents and wave patterns, causing erosion and sediment buildup that hurt nearby reefs. These changes disrupt ecosystems far from the islands. Experts agree the destruction of reefs from burial is mostly permanent. Small restoration efforts exist but cannot replace lost reefs. From above, the islands look solid, but underneath, broken reefs and damaged seabeds tell a different story. The environmental cost of creating these artificial lands reaches far beyond the visible shorelines. This report is based on Earth Island Institute findings.