The value of marine ecosystems
Oceans and coasts are among the nation’s most treasured and valuable resources. Americans rely on ocean ecosystems for food, jobs, recreation, energy, and other vital services. From fish and fisheries to whales, sea turtles, coral reefs, and oysters, many living marine resources and their habitats are at risk due to our rapidly changing and variable climate.
Climate-related changes in ocean and coastal ecosystems—including warming oceans, rising seas, ocean acidification, and coastal droughts—are impacting marine resources and, in turn, the people, businesses, and communities that depend on them. These changes affect jobs, impact economies, and disrupt traditional ways of life.
Changes to ecosystem productivity, species abundances, species distributions, and community interactions (including changes in predation or competition between species) are among the anticipated consequences. Species distribution shifts associated with rising ocean temperatures are already being observed. Less mobile species, such as corals, are not able to migrate with changing conditions to find suitable habitat. If conditions become unsuitable, some species will die off and no longer be a resource to help defend coastal communities from storms and inundation, or provide the foundation for tourism and recreation.
Businesses and communities that are dependent on particular fisheries and marine resources will need to find ways to adapt to the changes. Given the pace and scope of climate-related changes in marine and coastal ecosystems, decision makers need easy access to better information on what is changing, what is at risk, and what actions they can take to prepare for and respond to changing conditions. The tools and information provided here are intended to help people and communities take action to reduce climate-related impacts and increase resilience.
This section has been excerpted and abridged from the report Climate Change Impacts in the United States: The Third National Climate Assessment (Chapter 24: Oceans and Marine Resources) and Impacts, Risks, and Adaptation the United States: Fourth National Climate Assessment, Volume II: The Fourth National Climate Assessment (Chapter 9: Oceans and Marine Resources).
Learn more
To learn more about the impacts of climate change and variability on marine ecosystems and resources, visit the subtopic pages:
Ocean ecosystems provide food, jobs, recreation, energy, and other vital services for Americans. As a result of carbon-based exhaust accumulating in the atmosphere, these ocean resources are threatened by ocean warming, acidification, and deoxygenation. These changes threaten fisheries, aquaculture, and tourism, and the people and communities who depend on them.

Scene from a survey dive near Catalina Island, just off the southern California coast. Photograph by Adam Obaza, NOAA Fisheries, CC BY-NC-ND 2.0, https://creativecommons.org/licenses/by-nc-nd/2.0/ via Flickr