Commonwealth of the Northern Mariana Islands & Guam

In May – August 2015, Dr. Rebecca Gruby and research assistant Robbie Greene conducted research on the Marianas Trench Marine National Monument (MTMNM) in the U.S. territory of Guam and the Commonwealth of the Northern Mariana Islands (CNMI). Declared by presidential proclamation in January 2009, the MTMNM is one of two longer-established sites included in our study.

The MTMNM comprises 250,487km2 of submerged lands and waters and encompasses three distinct ‘units’: the waters and submerged lands of the three northernmost Mariana Islands (the Islands Unit), and the submerged lands of the Mariana Trench and certain volcanic sites (the Trench Unit and Volcanic Unit, respectively). The spatial disaggregation of the MTMNM boundaries is a unique design feature that affects governance and use of this remote ocean space.

The MTMNM has been a dynamic research site due in part to sociopolitical changes in the Northern Mariana Islands. The monument was designated at a time when the CNMI was adjusting to an increasing presence of U.S. military activity in the archipelago, and the application of U.S. labor and immigration laws to the commonwealth.

Current efforts to coordinate management of the MTMNM among federal and commonwealth agencies have been complicated by a broader political process surrounding the conveyance of submerged lands from the U.S. to the CNMI government, including those within the monument boundaries. As a longer-standing large MPA, the MTMNM remains a vibrant case study site due to emergent governance processes, evolving multi-scalar politics, and the persistence of cultural ties to remote ocean spaces.

We would like to thank all individuals in the Commonwealth of the Northern Mariana Islands & Guam (and beyond) who offered their time and assistance for this project. This work would not be possible without them.

For official information please see:

For more information about our research on the human dimensions of the MTMNM, please contact Rebecca Gruby at