LOS ANGELES, Oct. 20 (Xinhua) - The U.S. Center for Biological Diversity took a rare action Tuesday to protect coral species from extinction by filing a petition at the U.S. National Oceanic and Atmospheric Administration.

    The Center based in Tucson, Arizona sought to protect 83 imperiled coral species under the Endangered Species Act.

    The nonprofit organization said in the petition that those 83 coral species face a growing threat of extinction because of the global warming.

    Scientists said corals are among the species most imperiled by climate change. Stressed by warm ocean temperatures, corals experience bleaching, and many corals die or succumb to disease after bleaching.

    Scientists predict that most of the world's corals are subjected to mass bleaching events at deadly frequencies within 20years on the current emissions path.

    Scientists warned that coral reefs are likely to be the first worldwide ecosystem to collapse due to global warming.

    The petition from the Center for Biological Diversity marked the first time the U.S. government acknowledged global warming as a primary threat to the survival of a species.

    Under the Endangered Species Act, activities such as fishing, dumping, dredging and offshore oil development would be subject to stricter regulatory scrutiny.

    U.S. federal agencies are also required to ensure that their actions do not harm the coral species, which could result in agencies approving projects with significant greenhouse gas emissions to consider and minimize such impacts on vulnerable coral species.