Half above & half below view of waves breaking over the coral reefs of Ganh Yen, Quang Ngai province, Vietnam. The complex structure of the coral reefs with its innumerable branches and depressions strongly inhibits water flows and serves as a natural and reliable barrier that protects the coastline from waves. If global warming continues at the same rate and environmental factors continue threatening the coast, coral reefs structure will decrease and weaken, which will reduce the protection of the shoreline from high waves & making the underwater ecosystem more vulnerable.