Beneath the waters of China's Hainan island lie coral reefs that provide habitats and the foundation of food chains for numerous marine species. People on the island have been devoted to protecting and nurturing the corals for more than a decade. Under the guidance of marine experts, they put man-made reefs in the sea to create the growing conditions for corals, which in turn improves the habitat for fish. Thanks to their efforts, the ecosystem of coral reefs around the island is well-preserved.