The state of coral reef ecosystems of the Commonwealth of the Northern Mariana Islands : 2005 & 2008

Abstract

The 290 km long Mariana Islands Archipelago encompasses 14 islands of the U.S. Commonwealth of the Northern Mariana Islands (CNMI), the U.S. Territory of Guam, and numerous offshore banks. From a geological perspective, the islands can be divided into two groups: a southern and a northern island are region. Although the islands of the older southern arc, which includes Rota, Tinian, Saipan, and Farallon de Mendinilla (FDM), are volcanic in origin, they are nearly all covered with uplifted limestone derived from coral reefs. The West Mariana Ridge (WMR) is a series of seamounts, lying 145 to 170 km west of and parallel to the main island chains. Some of these mounts rise to within 13 m of the surface. The WMR is intermediate in age, as it is being younger than the southern island arc and older than the northern island arc. The southern are islands have the oldest and most developed reefs in the CNMI, which are predominantly located along the western (leeward) sides. The majority of the CNMI's residents live on Rota, Tinian, and Saipan, the capital.