Beaches in the CNMI are important coastal resources that connect visitors and residents to the ocean. These important ecosystems also have high recreational, aesthetic, economic, subsistence, and cultural value.
Their width and shape are naturally ever-changing with how sediment moves within our coast and ocean. However, swells and storms drive high energy waves into the shore and increase shoreline movement, which concerns beach loss. Beaches also provide a natural defense from waves. For certain beaches, erosion threatens nearby infrastructure close to the waterline and endangers users with hazardous footing. Storm-driven erosion is the primary cause of significant beach loss in the CNMI.
The Hyatt Regency to Crowne Plaza Resort is an actively eroding site. Each powerful storm has chipped away the berm, losing area that was once road and concessionaire space.
As sandy beach is lost, the vulnerability of beach front communities and infrastructure to storm surge and coastal erosion increase. Sea level rise is expected to cause retreat of coastlines worldwide.
To understand and document these interactions, DCRM’s Shoreline Monitoring Program studies beach sites to better inform coastal planning and development. Our team conducts field surveys at beach sites on Saipan to capture shoreline change, which often dictated by seasonal trade winds that drive sediment transport.
Learn all about DCRM’s Shoreline Monitoring work by checking out our interactive map! This was a proud product of the 2022 DCRM summer interns.
View the “Shoreline Trends” of the Climate Impact Viewer to see which sites have been eroding, accreting, exhibiting stability, or undetermined, and more!
shoreline monitoring beach profile reports
Click on any of the thumbnails below to view the detailed beach profile interpretations of the team for Saipan, Tinian, and Rota.
DCRM’s Beach Profile reports interpret beach profile information produced from our on-the-ground beach surveys. Beach profiles of the same place can tell us a lot of the whether the area is growing, losing, or staying the same throughout time.
beach profile activity
Beach Profile Activity is a hands-on learning activity developed by the team for educators. Educators can bring a simplified and affordable version of our field surveying procedure in their classrooms.
Students will gain hands-on experience on the importance of sandy shoreline and conceptualize how climate change impacts erosion. Available for download here.
Other local studies involving our shorelines are found on the Shoreline Publications page.
about the program
Since 2016, DCRM’s Shoreline Monitoring program surveys 17 beaches on Saipan, 9 beach transects on Mañagaha, 2 beaches on Tinian, and 4 beaches on Rota.
The team uses the Berger surveying method to identify, measure, and track changes within these sites. This data is developed into beach profiles for comparison. Through taking bi-annually beach profiles all of our target sites, we aim to understand our islands’ shoreline dynamics and report our findings yearly for data-driven decision making.
Our team comprises of DCRM staff, student interns, and volunteers. We acknowledge the notable contribution of NMC and DCRM Summer interns throughout the years to collect field data necessary for beach profiles and analysis.
We welcome requests for educational presentations or any questions regarding the program and its products.
Please contact the Shoreline Monitoring Program coordinator, Mary Fem Urena, at firstname.lastname@example.org or call 670-664-8324.
Terms on this page:
Accretion – The gradual addition of land by deposition of water-borne sediment
Berm – The nearly horizontal portion of the beach or backshore formed by the deposit of materials by wave action. Some beaches have no berms, while others have several. In the CNMI, the berm is a vertical drop
Beach Profile – The cross-sectional shape of a beach plotted perpendicular to the shoreline
Berger Level – The nearly horizontal portion of the beach or backshore formed by the deposit of materials by wave action. (In the CNMI, the berm is a vertical drop.)
Coastal Hazards – Phenomena that threaten structures, property, and the environment under extreme weather and water conditions
Coastal Planning – Planning process used to create informed management decisions for zoned coastal area. In the CNMI, all of Saipan, Tinian, and Rota are within the coastal zone.
Erosion – The wearing away of land and the removal of beach (or dune) sediments by wave action, tidal currents, drainage, or high winds
Headstake – The starting point of a transect. Usually marked on a tree or fixed point in paint
Rod Level – Used with a leveling instrument to determine the difference in height between points
Storm Surge – Abnormal rise in seawater level during a storm, measured as the height of the water above the normal predicted astronomical tide
Transect – A straight line or narrow section across the earth’s surface along which observations are made or measurements are taken
Vulnerability – The likelihood of people, property, industry, resources, ecosystems, or historical buildings and artifacts to coastal hazard impacts, such as shoreline erosion