A U.S. appeals court has revived a lawsuit seeking to block the construction of a new U.S. military base in Okinawa, Japan, over concerns about the base’s impacts on an endangered marine mammal called a dugong. The lawsuit is being brought by the Center for Biological Diversity. On Monday, a three-judge panel in San Francisco ruled the case can move forward. The proposed military base has also faced massive resistance by peace activists in Okinawa, who for decades have called for the expulsion of U.S. troops from their island.