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10 Things You May Not Know About Our Coasts

Scientists with the National and Regional Climate Adaptation Science Centers (CASCs) are actively working to understand and monitor climate change impacts on our coasts. Learn more with these 10 examples. 

Over 126 million people in the U.S., or 40 percent of the Nation’s total population, live in coastal counties. These coastal environments provide many benefits to their inhabitants, including both people and wildlife, and to the entire country. For example, coastal wetlands act as a natural defense against storm surge and also provide crucial food resources for waterfowl. However, coastal areas from Florida to Hawai'i and Alaska are threatened by changing conditions, such as rising seas, increasing water temperatures, more frequent extreme storms, and coastal erosion. Scientists with the National and Regional Climate Adaptation Science Centers (CASCs) are actively working to understand and monitor these impacts to inform the important adaptation decisions that natural and cultural resource managers working on our coastlines need to make. Learn more about our work in these 10 examples.

Aerial view of Kauai Island. (Public Domain)

1. Historic Sites & Sea Level RiseSome coastal cultural and historical sites, like Cape Lookout National Seashore and Jamestown, VA, are threatened by rising seas. With rising sea levels come elevated storm surges and an increased risk of flooding and shoreline erosion. The Northeast and Southeast CASCs are working with the National Park Service to pinpoint specific impacts to coastal cultural resources, such as the Cape Lookout Lighthouse (c. 1859) and Jamestown Church (c. 1639). Using projections of future climate conditions, managers can make important adaptation decisions, for example prioritizing sites that are most vulnerable to changing conditions and targeting these with adaptation efforts - such as relocating artifacts further inland or using more storm-resilient materials. Learn more about our work at Cape Lookout and Jamestown.

2. National Wildlife Refuges: Coastal National Wildlife Refuges (NWRs) provide habitat for wildlife, offer storm surge protection, and improve water quality, but are threatened by sea-level rise and extreme events. These threats ultimately can impact the ability of NWRs to protect our Nation’s natural resources and to sustain their many beneficial services. Southeast CASC researchers developed tools to help staff at NWRs in North and South Carolina understand potential future climate conditions and to inform the creation of management objectives based on these scenarios. This information can allow managers to more effectively adapt to the complex challenges facing the NWR system.

3. Tipping Points for Coastal Wildlife: As coastlines change, many species may be pushed to reach "ecological thresholds" - the tipping points at which changing conditions will disrupt their life cycle or habitat. For example, high salinity levels in marsh habitats can negatively affect the growth and survival of the mottled duck, a species that depends on marshes along the Gulf Coast. The Northeast CASC and partners synthesized scientific information on ecological thresholds for 45 species along the Atlantic and Gulf Coasts, offering insights to managers on potential strategies for managing coastal resources and protecting natural systems that sustain wildlife and the health and well-being of people and communities.  

4. Sea-level Rise Handbook: The Sea-Level Rise Modeling Handbook compiles complex information into a user-friendly guide to help managers plan for the impacts of rising seas. Scientists have developed a wealth of information and resources to predict and aid decision-making related to sea-level rise. To make this information more accessible and usable, Southeast CASC-supported scientists developed a detailed handbook and shorter quick-guide that summarize the available tools and data currently available for forecasting future scenarios of sea-level rise. These tools can guide resource managers and science users in determining which information is best suited to their specific needs.

A view of the gravel road along the coastline, looking east towards Kalapana. The active flow is just out of view on the left side of the photo. (Public domain)

5. Mapping Coastal Processes: Unmanned Aerial Systems can be used to monitor changes in coastal ecosystems and understand the impacts of extreme storms and sea-level rise. Because more traditional monitoring methods can be costly and time-consuming, and involve working in sensitive environments, a project supported by the Northeast CASC tested the utility of Unmanned Aerial Systems (UAS) for mapping and monitoring changes in coastal ecosystems. The study found that UAS provide a low-cost, low-risk means of acquiring high-resolution imagery. The scientific information gathered from these monitoring efforts are important for helping coastal managers understand impacts of storms and sea-level rise and plan for the future.

6. Submersed Aquatic Vegetation & Waterfowl: Saltwater intrusion due to rising seas is threatening the availability of vegetation that supports waterfowl. Sea-level rise has the potential to increase salinity in fresh and brackish wetlands, changing the distribution and composition of submersed aquatic vegetation (SAV) communities comprised of aquatic plants found in shallow waters. A project supported by the South Central CASC found that salinity and water depth are primary factors in determining the amount of SAV resources in marshes. This work is currently being used by the U.S. Fish and Wildlife Service in their restoration work on the Chandeleur Islands in the Gulf of Mexico and can help managers forecast the effects of future changes in SAV on waterfowl and other fish and wildlife species.

7. West Coast Tidal Wetlands: As climate conditions change, some tidal wetlands in Washington, Oregon, and California may be lost by the end of the century. Pacific tidal wetlands provide numerous services for coastal communities, such as filtering water, protecting communities from storm surges, providing habitat to endangered species, and supporting local fisheries. In a recent study, scientists supported by the Northwest and Southwest CASCs found that even the lowest predicted rates of sea-level rise could cause significant losses of some Pacific tidal wetlands by the end of the century. Information from this study offers insight for resource managers into a range of possible futures for tidal wetlands in this region.

8. Glaciers & Coasts: Rates of glacier loss are increasing in Southeast Alaska, causing significant impacts to coastal ecosystems in Alaska and the Pacific Northwest. Scientists and managers supported by the Alaska CASC are taking an “icefield to ocean” approach to understanding these changes. The team synthesized the impacts of glacier change on coastal ecosystems and found that as glaciers melt, their contents – namely, large quantities of freshwater, sediment, and nutrients – are released into streams and the ocean. The Northwest and Alaska CASCs also supported scientists to develop a tool to simulate future glacier melt and runoff into coastal environments. These efforts provide valuable information to managers concerned with the economy and ecology of this region, such as those in the fishing and tourism industries.

Healthy coral reef in St. Croix, US Virgin Islands.
Healthy coral reef in St. Croix, US Virgin Islands (Public domain)

9. Coastal Erosion & Flooding: Beach loss negatively impacts habitat for rare and endangered species and increases the exposure of coastal infrastructure to flooding and storms. On the Hawaiian island of Kauaʻi, the rate of coastal erosion is expected to double by 2050. Scientists supported by the Pacific Islands CASC developed interactive maps that show which areas of Kauaʻi’s coastline are most vulnerable to future erosion. In another project, scientists are evaluating the impacts of sea-level rise on Majuro Atoll in the Marshall Islands. Majuro’s highest point is just 10 feet above sea level, and residents are already experiencing significant flood events that damage infrastructure and contaminate freshwater supplies. Information from these projects is supporting hazard preparedness and adaptation planning in the Pacific Islands on state and local scales.

10. Coral Reefs: Coral reefs are sometimes called “rainforests of the sea” because of their immense biological diversity and economic value, but many reefs are threatened by changing conditions. Pacific Islands CASC-supported scientists collaborated with local managers to survey reefs at 78 locations throughout the Commonwealth of the Northern Mariana Islands (CNMI) to evaluate their resilience to changes in the environment, such as changing water temperatures or chemistry. Their findings help managers highlight priority sites for management action and identify which management actions - such as  fisheries regulation, pollution reduction, reef restoration, and monitoring - could best support natural resilience at each site.

This year, 2018, marks the 10-year anniversary of the establishment of the National Climate Adaptation Science Center (NCASC; formerly named the National Climate Change and Wildlife Science Center). In those 10-years, the eight regional Climate Adaptation Science Centers (CASCs; formerly named the Climate Science Centers) were established. Together, the National and Regional CASCs funded over 425 science projects and built a network of research partners, resource management stakeholders, interdisciplinary staff, fellows, and early career researchers.

In celebration of our work and accomplishments over the last 10 years, we have launched a monthly series featuring “10 Things You May Not Know” about different topics our science has focused on, including drought, glaciers, and wildfire. Stayed tuned next month for the next part in the series! Learn more in the posts below:

10 Things You May Not Know About: