Coral reefs act like submerged breakwaters by breaking waves and dissipating their energy offshore before they flood coastal properties and communities. This is an enormously valuable function: In 2017, Hurricanes Harvey, Irma and Maria alone caused over $265 billion in damage across the nation.
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.
Sources/Usage: Public Domain. View Media Details
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.
Sources/Usage: Public Domain. View Media Details
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.
Sources/Usage: Public Domain. View Media Details
Learn about our current studies by topic.
Climate Change and Land-use Histories
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.
Also, learn about our studies by location:
- Guam
- Hawai‛i
- Kaho‛olawe
- Kaua‛i
- Kwajalein Island
- Lāna‛i
- Maui
- Moloka‛i
- O‛ahu
- Puerto Rico
- Roi-Namur Island
- Tutuila
Please also see the associated Coral Reef Ecosystem Studies (CREST) Project website.
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
Learn more about our related studies, and read basic facts about corals and reefs.
Guam coastal imagery and waves
Guam coastal imagery and waves
View our web page that shows coastal imagery and wave characteristics near Adelup Point, Guam.
USGS Coral Reef Project
USGS Coral Reef Project
Filter Total Items: 23
Anthropogenic Nutrient Loading and Coral Health at Ofu, American Samoa
Declining water quality poses a significant and persistent threat to coral reefs worldwide, contributing to their widespread degradation. Identifying the specific impacts of water quality stressors is challenging due to the complex interplay of various physical and biological factors affecting reef health. Submarine groundwater discharge (SGD) plays a crucial role in transporting nutrients into...
Reef Hydrodynamics and Sediment Processes
As part of the USGS Coral Reef Project, the overall objective of this research effort is to better understand how circulation and sediment processes impact coral reefs and their adjacent coastlines.
Low-lying areas of tropical Pacific islands
Sea level is rising faster than projected in the western Pacific, so understanding how wave-driven coastal flooding will affect inhabited, low-lying islands—most notably, the familiar ring-shaped atolls—as well as the low-elevation areas of high islands in the Pacific Ocean, is critical for decision-makers in protecting infrastructure or relocating resources and people.
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.
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.
The Impact of Sea-Level Rise and Climate Change on Pacific Ocean Atolls
Providing basic understanding and specific information on storm-wave inundation of atoll islands that house Department of Defense installations, and assessing the resulting impact of sea-level rise and storm-wave inundation on infrastructure and freshwater availability under a variety of sea-level rise and climatic scenarios.
Coral Reef Project: Kwajalein Island
The USGS is working to provide a better understanding of how spatially-varying atoll morphology and coral cover interact with changes in water level to affect the propagation of waves of different heights and wavelengths across atoll reefs.
Coral Reef Project: Roi-Namur Island
The USGS is working to provide a better understanding of how spatially-varying atoll morphology and coral cover interact with changes in water level to affect the propagation of waves of different heights and wavelengths across atoll reefs.
Hydrogeology and Reef Health
As part of the USGS Coral Reef Project, 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.
Coral Reef Project: Maui
As part of USGS Coral Reef Project studies, the USGS has been heavily involved in efforts to improve the health and resilience of Maui's coral reef system, bringing expertise in mapping, circulation and sediment studies, and seismic surveys.
Coral Reef Project: Molokaʻi
As part of the USGS Coral Reef Project, recent USGS work on Molokaʻi includes looking into the coral record to find clues to past sedimentation events.
Quantifying Flood Risk and Reef Risk Reduction Benefits in Florida and Puerto Rico: The Consequences of Hurricane Damage, Long-term Degradation, and Restoration Opportunities
Coastal flooding and erosion from extreme weather events affect thousands of vulnerable coastal communities; the impacts of coastal flooding are predicted to worsen during this century because of population growth and climate change. Hurricanes Irma and Maria in 2017 were particularly devasting to humans and natural communities. The coral reefs off the State of Florida and the Commonwealth of...
Below are multimedia items associated with this project.
Curt Storlazzi - Coral Reefs as National, Natural Infrastructure
Coral reefs act like submerged breakwaters by breaking waves and dissipating their energy offshore before they flood coastal properties and communities. This is an enormously valuable function: In 2017, Hurricanes Harvey, Irma and Maria alone caused over $265 billion in damage across the nation.
Reducing Flood Risks by Restoring Coral Reefs
How Our Reefs Protect Us: Valuing the Benefits of U.S. Reefs
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards during storms. The protective services of these natural defenses are not assessed in the same rigorous economic terms as artificial defenses, such as seawalls, and therefore often are not considered in decision-making.
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards during storms. The protective services of these natural defenses are not assessed in the same rigorous economic terms as artificial defenses, such as seawalls, and therefore often are not considered in decision-making.
PubTalk 4/2018 - Coral Reefs
Title: The Role of U.S. Coral Reefs in Coastal Protection - Rigorously valuing flood reduction benefits to inform coastal zone management decisions
Title: The Role of U.S. Coral Reefs in Coastal Protection - Rigorously valuing flood reduction benefits to inform coastal zone management decisions
What's Drifting Beneath Kauai's Ocean?
Residents and visitors both revel in Kauai’s lush landscape, and beneath its seascape. However, it’s underwater where things don’t look so healthy. Scientists from the U.S. Geological Survey put together a detailed picture of the physical environment of the coral reefs at Makua Beach.
Residents and visitors both revel in Kauai’s lush landscape, and beneath its seascape. However, it’s underwater where things don’t look so healthy. Scientists from the U.S. Geological Survey put together a detailed picture of the physical environment of the coral reefs at Makua Beach.
Breaking Down Reefs, Building Up Beaches
On the remote western coast of Australia lies a UNESCO World Heritage Site above and below the sea. Researchers from the U.S. Geological Survey and University of Western Australia convened here at Ningaloo Reef and Jurabi Coastal Reserve to embark on the most extensive study EVER done into how coral reefs shape our coasts.
On the remote western coast of Australia lies a UNESCO World Heritage Site above and below the sea. Researchers from the U.S. Geological Survey and University of Western Australia convened here at Ningaloo Reef and Jurabi Coastal Reserve to embark on the most extensive study EVER done into how coral reefs shape our coasts.
Exploring Causes of Coral Disease
The Hawaiian Islands’ beautiful ocean and beaches attract more than 8.5 million tourists each year. The USGS aims to help Hawaii preserve its underwater natural resources by tracing how oceanography may influence coral disease outbreaks.
The Hawaiian Islands’ beautiful ocean and beaches attract more than 8.5 million tourists each year. The USGS aims to help Hawaii preserve its underwater natural resources by tracing how oceanography may influence coral disease outbreaks.
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.
Sources/Usage: Public Domain. View Media Details
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.
Sources/Usage: Public Domain. View Media Details
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.
Sources/Usage: Public Domain. View Media Details
Learn about our current studies by topic.
Climate Change and Land-use Histories
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.
Also, learn about our studies by location:
- Guam
- Hawai‛i
- Kaho‛olawe
- Kaua‛i
- Kwajalein Island
- Lāna‛i
- Maui
- Moloka‛i
- O‛ahu
- Puerto Rico
- Roi-Namur Island
- Tutuila
Please also see the associated Coral Reef Ecosystem Studies (CREST) Project website.
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
Learn more about our related studies, and read basic facts about corals and reefs.
Guam coastal imagery and waves
Guam coastal imagery and waves
View our web page that shows coastal imagery and wave characteristics near Adelup Point, Guam.
USGS Coral Reef Project
USGS Coral Reef Project
Filter Total Items: 23
Anthropogenic Nutrient Loading and Coral Health at Ofu, American Samoa
Declining water quality poses a significant and persistent threat to coral reefs worldwide, contributing to their widespread degradation. Identifying the specific impacts of water quality stressors is challenging due to the complex interplay of various physical and biological factors affecting reef health. Submarine groundwater discharge (SGD) plays a crucial role in transporting nutrients into...
Reef Hydrodynamics and Sediment Processes
As part of the USGS Coral Reef Project, the overall objective of this research effort is to better understand how circulation and sediment processes impact coral reefs and their adjacent coastlines.
Low-lying areas of tropical Pacific islands
Sea level is rising faster than projected in the western Pacific, so understanding how wave-driven coastal flooding will affect inhabited, low-lying islands—most notably, the familiar ring-shaped atolls—as well as the low-elevation areas of high islands in the Pacific Ocean, is critical for decision-makers in protecting infrastructure or relocating resources and people.
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.
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.
The Impact of Sea-Level Rise and Climate Change on Pacific Ocean Atolls
Providing basic understanding and specific information on storm-wave inundation of atoll islands that house Department of Defense installations, and assessing the resulting impact of sea-level rise and storm-wave inundation on infrastructure and freshwater availability under a variety of sea-level rise and climatic scenarios.
Coral Reef Project: Kwajalein Island
The USGS is working to provide a better understanding of how spatially-varying atoll morphology and coral cover interact with changes in water level to affect the propagation of waves of different heights and wavelengths across atoll reefs.
Coral Reef Project: Roi-Namur Island
The USGS is working to provide a better understanding of how spatially-varying atoll morphology and coral cover interact with changes in water level to affect the propagation of waves of different heights and wavelengths across atoll reefs.
Hydrogeology and Reef Health
As part of the USGS Coral Reef Project, 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.
Coral Reef Project: Maui
As part of USGS Coral Reef Project studies, the USGS has been heavily involved in efforts to improve the health and resilience of Maui's coral reef system, bringing expertise in mapping, circulation and sediment studies, and seismic surveys.
Coral Reef Project: Molokaʻi
As part of the USGS Coral Reef Project, recent USGS work on Molokaʻi includes looking into the coral record to find clues to past sedimentation events.
Quantifying Flood Risk and Reef Risk Reduction Benefits in Florida and Puerto Rico: The Consequences of Hurricane Damage, Long-term Degradation, and Restoration Opportunities
Coastal flooding and erosion from extreme weather events affect thousands of vulnerable coastal communities; the impacts of coastal flooding are predicted to worsen during this century because of population growth and climate change. Hurricanes Irma and Maria in 2017 were particularly devasting to humans and natural communities. The coral reefs off the State of Florida and the Commonwealth of...
Below are multimedia items associated with this project.
Curt Storlazzi - Coral Reefs as National, Natural Infrastructure
Coral reefs act like submerged breakwaters by breaking waves and dissipating their energy offshore before they flood coastal properties and communities. This is an enormously valuable function: In 2017, Hurricanes Harvey, Irma and Maria alone caused over $265 billion in damage across the nation.
Coral reefs act like submerged breakwaters by breaking waves and dissipating their energy offshore before they flood coastal properties and communities. This is an enormously valuable function: In 2017, Hurricanes Harvey, Irma and Maria alone caused over $265 billion in damage across the nation.
Reducing Flood Risks by Restoring Coral Reefs
How Our Reefs Protect Us: Valuing the Benefits of U.S. Reefs
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards during storms. The protective services of these natural defenses are not assessed in the same rigorous economic terms as artificial defenses, such as seawalls, and therefore often are not considered in decision-making.
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards during storms. The protective services of these natural defenses are not assessed in the same rigorous economic terms as artificial defenses, such as seawalls, and therefore often are not considered in decision-making.
PubTalk 4/2018 - Coral Reefs
Title: The Role of U.S. Coral Reefs in Coastal Protection - Rigorously valuing flood reduction benefits to inform coastal zone management decisions
Title: The Role of U.S. Coral Reefs in Coastal Protection - Rigorously valuing flood reduction benefits to inform coastal zone management decisions
What's Drifting Beneath Kauai's Ocean?
Residents and visitors both revel in Kauai’s lush landscape, and beneath its seascape. However, it’s underwater where things don’t look so healthy. Scientists from the U.S. Geological Survey put together a detailed picture of the physical environment of the coral reefs at Makua Beach.
Residents and visitors both revel in Kauai’s lush landscape, and beneath its seascape. However, it’s underwater where things don’t look so healthy. Scientists from the U.S. Geological Survey put together a detailed picture of the physical environment of the coral reefs at Makua Beach.
Breaking Down Reefs, Building Up Beaches
On the remote western coast of Australia lies a UNESCO World Heritage Site above and below the sea. Researchers from the U.S. Geological Survey and University of Western Australia convened here at Ningaloo Reef and Jurabi Coastal Reserve to embark on the most extensive study EVER done into how coral reefs shape our coasts.
On the remote western coast of Australia lies a UNESCO World Heritage Site above and below the sea. Researchers from the U.S. Geological Survey and University of Western Australia convened here at Ningaloo Reef and Jurabi Coastal Reserve to embark on the most extensive study EVER done into how coral reefs shape our coasts.
Exploring Causes of Coral Disease
The Hawaiian Islands’ beautiful ocean and beaches attract more than 8.5 million tourists each year. The USGS aims to help Hawaii preserve its underwater natural resources by tracing how oceanography may influence coral disease outbreaks.
The Hawaiian Islands’ beautiful ocean and beaches attract more than 8.5 million tourists each year. The USGS aims to help Hawaii preserve its underwater natural resources by tracing how oceanography may influence coral disease outbreaks.