Pacific Island Ecosystems Research Center
Guam and the Mariana Islands
The Mariana Islands (also called “The Marianas”) are an arc-shaped archipelago of 15 volcanic islands bordering the Philippine Sea, south of Japan and north of New Guinea. The Marianas are considered to lie in the northern part of Micronesia, although their government is under a different jurisdiction from much of the rest of geographical Micronesia. Today, the Marianas are composed of two U.S. jurisdictions: the Territory of Guam and the Commonwealth of the Northern Mariana Islands. These islands rise out of the deepest known submarine trench in the world, now protected as the Marianas Trench Marine National Monument. War in the Pacific National Historical Park and American Memorial Park commemorate fierce fighting of World War II, and the U.S. military remains a key conservation partner in the region. PIERC partnership with Department of Interior includes research at the Guam National Wildlife Refuge and islands to the north.