The Value of Our Reefs
Cost-benefit study confirms coral reef restoration could be a cost-effective way to save lives and money
Explore the fascinating undersea world of coral reefs. Learn how we map, monitor, and model coral reefs so we can better understand, protect, and preserve our Nation's reefs.
Coral reefs are unique ecosystems of plants, animals, and their associated geological framework. Coral reefs cover less than 0.5 percent of the earth's surface, but are home to an estimated 25 percent of all marine species. Second only to tropical rainforests in size and complexity, some scientists estimate that more than one million species of plants and animals are associated with coral reefs.
Coral reefs are also of great economic importance to those who live on or visit islands in the Pacific and Atlantic Oceans. Reefs shelter and provide nursery grounds for many commercially and culturally important species of fish and invertebrates, they protect the islands' harbors, beaches, and shorelines from erosion and wave damage by storms, and they are vital to the marine tourism industry. These diverse ecosystems provide valuable goods and services worth about $4 billion each year to the U.S.’s coastal communities. Yet, as important as coral reefs are, these ecosystems are being threatened worldwide.
More than 8,500 square miles (22,000 square kilometers) of coral reef habitat is found in U.S. waters. Most of these coral reefs still appear to be relatively healthy, but some areas of dead and dying coral have been found in recent years. The causes of this degradation are poorly known, but are probably in part related to human activities.
The U.S. Geological Survey (USGS), working closely with academic institutions, state, and other Federal agencies, is spearheading an effort to better understand the geologic and oceanographic controls on the structure and processes of our Nation's coral reef ecosystems.
This web site is a gateway to USGS studies of coral reefs. We focus on the geophysical processes that influence the health and sustainability of coral reefs. From this work we are gaining new insight into the structure of coral reefs, providing the basis for future monitoring, and understanding better both the influences of natural processes and impacts of human activities on coral reef health. These efforts will help to preserve and protect the biodiversity, health, and social and economic value of these remarkable habitats.
Read more coral reef facts.
Learn about our current studies by topic:
We are developing new and unique oceanographic and environmental archives from coral skeleton records to better understand the compounding effects of land-use and environmental change on coral reef health.
We are conducting geophysical and geochemical research to address questions about coastal groundwater-to-reef flow and coral reef health, with the goal of informing management decisions related to planning and implementing activities in priority watershed-coral reef systems.
Reef Hydrodynamics and Sediment Processes
We are developing a better understanding how tides, waves, currents, and both land- and reef-derived sediment influence the development of coral reefs and their adjacent shorelines.
Role of Reefs in Coastal Protection
We are combining ocean, engineering, ecologic, social, and economic modeling to provide a high-resolution, rigorous, spatially-explicit valuation of the coastal flood protection benefits provided by coral reefs and the cost effectiveness of reef restoration for enhancing those benefits.
Reef Resource Assessments - Planning for the Future
We are mapping and assessing all of the important geologic and oceanographic factors to identify those coral reefs most at risk and those reefs that are potentially the most resilient and the most likely to recover from natural and human-driven impacts.
Learn about our studies by location:
Guam
Hawaiʻi
Kahoʻolawe
Kauaʻi
Kwajalein Island
Lānaʻi
Maui
Molokaʻi
Oʻahu
Puerto Rico
Roi-Namur Island
Tutuila
Our partners are numerous and include:
- U.S. Coral Reef Task Force (USCRTF)
- Department of the Interior
- Other Federal Partners
- State Partners
- Territorial and Commonwealth Partners
- Guam Division of Aquatic and Wildlife Resources
- Commonwealth of the Northern Mariana Islands Department of Land and Natural Resources
- American Samoa Department of Marine and Wildlife Resources
- Puerto Rico Department of Natural and Environmental Resources
- U.S. Virgin Islands Department of Planning and Natural Resources
- Academia
- University of California Santa Cruz - Institute of Marine Sciences
- University of Western Australia - Oceans Institute
- University of Puerto Rico at Mayaguez - Center for Applied Ocean Science & Engineering
- University of Hawaiʻi - Hawaiʻi Institute of Marine Biology
- Woods Hole Oceanographic Institution - Department of Geology and Geophysics
- Delft University of Technology - Department of Hydraulic Engineering
- Queen's University - Department of Civil Engineering
- University of Cantabria - Department of Sciences and Techniques in Water and Environment
- Non-governmental Organizations
Below are data releases associated with this project.
Physics-based numerical circulation model outputs of ocean surface circulation during the 2010-2013 summer coral-spawning seasons in Maui Nui, Hawaii, USA Physics-based numerical circulation model outputs of ocean surface circulation during the 2010-2013 summer coral-spawning seasons in Maui Nui, Hawaii, USA
Still-image frame grabs and benthic habitat interpretation of underwater video footage, March 2014, Faga'alu Bay, Tutuila Island, American Samoa Still-image frame grabs and benthic habitat interpretation of underwater video footage, March 2014, Faga'alu Bay, Tutuila Island, American Samoa
Underwater Video Footage, March 2014, Faga`alu Bay, Tutuila Island, American Samoa Underwater Video Footage, March 2014, Faga`alu Bay, Tutuila Island, American Samoa
Below are multimedia items associated with this project.
Below is a list of our project publications.
A numerical study of wave-driven mean flows and setup dynamics at a coral reef-lagoon system A numerical study of wave-driven mean flows and setup dynamics at a coral reef-lagoon system
The contribution of currents, sea-swell waves, and infragravity waves to suspended-sediment transport across a coral reef-lagoon system. The contribution of currents, sea-swell waves, and infragravity waves to suspended-sediment transport across a coral reef-lagoon system.
Role of future reef growth on morphological response of coral reef islands to sea-level rise Role of future reef growth on morphological response of coral reef islands to sea-level rise
Nearshore water quality and coral health indicators along the west coast of the Island of Hawaiʻi, 2010–2014 Nearshore water quality and coral health indicators along the west coast of the Island of Hawaiʻi, 2010–2014
Spectral wave-driven bedload transport across a coral reef flat/lagoon complex Spectral wave-driven bedload transport across a coral reef flat/lagoon complex
Internal tides can provide thermal refugia that will buffer some coral reefs from future global warming Internal tides can provide thermal refugia that will buffer some coral reefs from future global warming
The importance of explicitly modelling sea-swell waves for runup on reef-lined coasts The importance of explicitly modelling sea-swell waves for runup on reef-lined coasts
In situ observations of wave transformation and infragravity bore development across reef flats of varying geomorphology In situ observations of wave transformation and infragravity bore development across reef flats of varying geomorphology
Hydro-morphological characterization of coral reefs for wave runup prediction Hydro-morphological characterization of coral reefs for wave runup prediction
Physicochemical controls on zones of higher coral stress where Black Band Disease occurs at Mākua Reef, Kauaʻi, Hawaiʻi Physicochemical controls on zones of higher coral stress where Black Band Disease occurs at Mākua Reef, Kauaʻi, Hawaiʻi
The major coral reefs of Maui Nui, Hawai‘i—distribution, physical characteristics, oceanographic controls, and environmental threats The major coral reefs of Maui Nui, Hawai‘i—distribution, physical characteristics, oceanographic controls, and environmental threats
The risk reduction benefits of the Mesoamerican Reef in Mexico The risk reduction benefits of the Mesoamerican Reef in Mexico
Below are news stories associated with this project.
USGS Investigations of coral reefs are cooperative efforts, and our scientists are working in partnership and cooperation with the following organizations.
Explore the fascinating undersea world of coral reefs. Learn how we map, monitor, and model coral reefs so we can better understand, protect, and preserve our Nation's reefs.
Coral reefs are unique ecosystems of plants, animals, and their associated geological framework. Coral reefs cover less than 0.5 percent of the earth's surface, but are home to an estimated 25 percent of all marine species. Second only to tropical rainforests in size and complexity, some scientists estimate that more than one million species of plants and animals are associated with coral reefs.
Coral reefs are also of great economic importance to those who live on or visit islands in the Pacific and Atlantic Oceans. Reefs shelter and provide nursery grounds for many commercially and culturally important species of fish and invertebrates, they protect the islands' harbors, beaches, and shorelines from erosion and wave damage by storms, and they are vital to the marine tourism industry. These diverse ecosystems provide valuable goods and services worth about $4 billion each year to the U.S.’s coastal communities. Yet, as important as coral reefs are, these ecosystems are being threatened worldwide.
More than 8,500 square miles (22,000 square kilometers) of coral reef habitat is found in U.S. waters. Most of these coral reefs still appear to be relatively healthy, but some areas of dead and dying coral have been found in recent years. The causes of this degradation are poorly known, but are probably in part related to human activities.
The U.S. Geological Survey (USGS), working closely with academic institutions, state, and other Federal agencies, is spearheading an effort to better understand the geologic and oceanographic controls on the structure and processes of our Nation's coral reef ecosystems.
This web site is a gateway to USGS studies of coral reefs. We focus on the geophysical processes that influence the health and sustainability of coral reefs. From this work we are gaining new insight into the structure of coral reefs, providing the basis for future monitoring, and understanding better both the influences of natural processes and impacts of human activities on coral reef health. These efforts will help to preserve and protect the biodiversity, health, and social and economic value of these remarkable habitats.
Read more coral reef facts.
Learn about our current studies by topic:
We are developing new and unique oceanographic and environmental archives from coral skeleton records to better understand the compounding effects of land-use and environmental change on coral reef health.
We are conducting geophysical and geochemical research to address questions about coastal groundwater-to-reef flow and coral reef health, with the goal of informing management decisions related to planning and implementing activities in priority watershed-coral reef systems.
Reef Hydrodynamics and Sediment Processes
We are developing a better understanding how tides, waves, currents, and both land- and reef-derived sediment influence the development of coral reefs and their adjacent shorelines.
Role of Reefs in Coastal Protection
We are combining ocean, engineering, ecologic, social, and economic modeling to provide a high-resolution, rigorous, spatially-explicit valuation of the coastal flood protection benefits provided by coral reefs and the cost effectiveness of reef restoration for enhancing those benefits.
Reef Resource Assessments - Planning for the Future
We are mapping and assessing all of the important geologic and oceanographic factors to identify those coral reefs most at risk and those reefs that are potentially the most resilient and the most likely to recover from natural and human-driven impacts.
Learn about our studies by location:
Guam
Hawaiʻi
Kahoʻolawe
Kauaʻi
Kwajalein Island
Lānaʻi
Maui
Molokaʻi
Oʻahu
Puerto Rico
Roi-Namur Island
Tutuila
Our partners are numerous and include:
- U.S. Coral Reef Task Force (USCRTF)
- Department of the Interior
- Other Federal Partners
- State Partners
- Territorial and Commonwealth Partners
- Guam Division of Aquatic and Wildlife Resources
- Commonwealth of the Northern Mariana Islands Department of Land and Natural Resources
- American Samoa Department of Marine and Wildlife Resources
- Puerto Rico Department of Natural and Environmental Resources
- U.S. Virgin Islands Department of Planning and Natural Resources
- Academia
- University of California Santa Cruz - Institute of Marine Sciences
- University of Western Australia - Oceans Institute
- University of Puerto Rico at Mayaguez - Center for Applied Ocean Science & Engineering
- University of Hawaiʻi - Hawaiʻi Institute of Marine Biology
- Woods Hole Oceanographic Institution - Department of Geology and Geophysics
- Delft University of Technology - Department of Hydraulic Engineering
- Queen's University - Department of Civil Engineering
- University of Cantabria - Department of Sciences and Techniques in Water and Environment
- Non-governmental Organizations
Below are data releases associated with this project.
Physics-based numerical circulation model outputs of ocean surface circulation during the 2010-2013 summer coral-spawning seasons in Maui Nui, Hawaii, USA Physics-based numerical circulation model outputs of ocean surface circulation during the 2010-2013 summer coral-spawning seasons in Maui Nui, Hawaii, USA
Still-image frame grabs and benthic habitat interpretation of underwater video footage, March 2014, Faga'alu Bay, Tutuila Island, American Samoa Still-image frame grabs and benthic habitat interpretation of underwater video footage, March 2014, Faga'alu Bay, Tutuila Island, American Samoa
Underwater Video Footage, March 2014, Faga`alu Bay, Tutuila Island, American Samoa Underwater Video Footage, March 2014, Faga`alu Bay, Tutuila Island, American Samoa
Below are multimedia items associated with this project.
Below is a list of our project publications.
A numerical study of wave-driven mean flows and setup dynamics at a coral reef-lagoon system A numerical study of wave-driven mean flows and setup dynamics at a coral reef-lagoon system
The contribution of currents, sea-swell waves, and infragravity waves to suspended-sediment transport across a coral reef-lagoon system. The contribution of currents, sea-swell waves, and infragravity waves to suspended-sediment transport across a coral reef-lagoon system.
Role of future reef growth on morphological response of coral reef islands to sea-level rise Role of future reef growth on morphological response of coral reef islands to sea-level rise
Nearshore water quality and coral health indicators along the west coast of the Island of Hawaiʻi, 2010–2014 Nearshore water quality and coral health indicators along the west coast of the Island of Hawaiʻi, 2010–2014
Spectral wave-driven bedload transport across a coral reef flat/lagoon complex Spectral wave-driven bedload transport across a coral reef flat/lagoon complex
Internal tides can provide thermal refugia that will buffer some coral reefs from future global warming Internal tides can provide thermal refugia that will buffer some coral reefs from future global warming
The importance of explicitly modelling sea-swell waves for runup on reef-lined coasts The importance of explicitly modelling sea-swell waves for runup on reef-lined coasts
In situ observations of wave transformation and infragravity bore development across reef flats of varying geomorphology In situ observations of wave transformation and infragravity bore development across reef flats of varying geomorphology
Hydro-morphological characterization of coral reefs for wave runup prediction Hydro-morphological characterization of coral reefs for wave runup prediction
Physicochemical controls on zones of higher coral stress where Black Band Disease occurs at Mākua Reef, Kauaʻi, Hawaiʻi Physicochemical controls on zones of higher coral stress where Black Band Disease occurs at Mākua Reef, Kauaʻi, Hawaiʻi
The major coral reefs of Maui Nui, Hawai‘i—distribution, physical characteristics, oceanographic controls, and environmental threats The major coral reefs of Maui Nui, Hawai‘i—distribution, physical characteristics, oceanographic controls, and environmental threats
The risk reduction benefits of the Mesoamerican Reef in Mexico The risk reduction benefits of the Mesoamerican Reef in Mexico
Below are news stories associated with this project.
USGS Investigations of coral reefs are cooperative efforts, and our scientists are working in partnership and cooperation with the following organizations.