Sea-Level Rise and Coasts

The Northeast U.S. coast is experiencing some of the fastest rates of sea level rise in the world. The Boston Harbor Islands National Recreation Area is particularly at risk from sea level rise and coastal storm impacts. Erosion and storm impacts have already led to the degradation of shoreline habitats and protective structures (e.g., sea walls), as well as direct impacts to historic...

Freshwater is a critical driver for island ecosystems. In Hawaiʻi, though rainfall intensity has increased, total rainfall has been on the decline for the last two decades and, as a result, streamflow has also been reduced. The changes in dynamic patterns of streamflow could result in impacts to river, estuarine, and coastal habitats. In turn, these changes also affect the nine native...

Residents living along the coast of Lake Ontario and the St. Lawrence River have experienced two record-setting floods, one in 2017 and another in 2019. These floods caused tremendous property damage and disruptions to the regional economy. The water levels on Lake Ontario are influenced by the operations of the Moses Saunders Dam on the St. Lawrence River. These operations are...

As a low-lying coastal nation, the Republic of the Marshall Islands is at the forefront of exposure to climate change impacts. The Republic of the Marshall Islands has a strong dependence on natural resources and biodiversity not only for food and income but also for culture and livelihood. However, these resources are threatened by rising sea levels and associated coastal hazards (storm...

The fast pace of change in coastal zones, the trillions of dollars of investment in human communities in coastal areas, and the myriad of ecosystem services natural coastal environments provide makes managing climate-related risks along coasts a massive challenge for all of the U.S. coastal states and territories. Answering questions about both the costs and the benefits of alternative...

The Republic of Palau, a Freely Associated State of the U.S. and a global leader in ocean conservation, recently implemented the Palau National Marine Sanctuary, which closed 80% of its ocean to fishing. As offshore fish become scarcer in the domestic market, managers have begun to worry about increased harvesting pressure on already overfished nearshore environments. This pressure, in...

Globally, shorelines provide a vital defense system against extreme weather and erosion events and are a critical public and cultural resource. Within the state of Hawaiʻi, coastal vulnerability and historic change has been well documented and studied on the Islands of Oʻahu, Maui, and Kauaʻi, but this has not been done for the Island of Hawaiʻi, the largest and most diverse island in...

Loss of saltmarsh habitat is one of the biggest threats to coastal sustainability in the Northeast. Salt marsh has been identified as an essential fish and wildlife habitat, and loss of saltmarsh corresponds with precipitous declines in marsh-dependent wildlife. For example, the global population of Saltmarsh Sparrow is predicted to collapse within the next 50 years after experiencing a...

Mangroves are forested tidal wetlands that occur in tropical, sub-tropical, and warm temperate coastal regions around the world. Mangroves occupy a significant area of coastlines globally and provide important ecosystem services to humans and wildlife. These services include aesthetic value, storm protection, food provisioning, recreation, critical wildlife habitat, and biological carbon

American Samoa is vulnerable to sea-level rise in part due to the steep terrain of its islands. This terrain requires the majority of the islands’ villages and infrastructure to be located along thin strips of coastal land. The situation is worsened by the recently recognized rapid sinking of the islands, which was triggered by the 2009 Samoa earthquake and is predicted to last for...

Ecosystems such as coral reefs and mangroves provide an effective first line of defense against coastal hazards and represent a promising nature-based solution to adapt to sea-level rise. In many areas, coral reefs cause waves to break and lose energy, allowing for sediment to accumulate on the inshore portion of reef flats (i.e. the shallowest, flattest part of a reef) and mangroves to...

The Science Issue and Relevance: Coastal wetlands are some of the most productive and valuable habitats in the world. Louisiana contains 40% of the United States’ coastal wetlands, which provide critical habitat for waterfowl and fisheries, as well as many other benefits, such as storm surge protection for coastal communities. In terms of ecosystem services, biological resource...