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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.
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.
Our partners are numerous and include:
Learn more about our related studies, and read basic facts about corals and reefs.
View our web page that shows coastal imagery and wave characteristics near Adelup Point, Guam.
Below are multimedia items associated with this project.
Coral reef restoration can protect hundreds of millions of dollars of coastal property and business activity annually from storm-driven flooding.
It can protect thousands of people, especially children, the elderly, minorities, and those below the poverty line. Thus, coral reef restoration is a mechanism to provide environmental equity.
Coral reef restoration can protect hundreds of millions of dollars of coastal property and business activity annually from storm-driven flooding.
It can protect thousands of people, especially children, the elderly, minorities, and those below the poverty line. Thus, coral reef restoration is a mechanism to provide environmental equity.
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.
Along reef-lined shores of the Pacific Islands, USGS Research Geologist and Oceanographer Ferdinand Oberle studies how warming surface waters, nutrient runoff, and increasingly powerful storms impact coral reefs.
Along reef-lined shores of the Pacific Islands, USGS Research Geologist and Oceanographer Ferdinand Oberle studies how warming surface waters, nutrient runoff, and increasingly powerful storms impact coral 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.
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
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.
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.
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.
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.
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.
Our partners are numerous and include:
Learn more about our related studies, and read basic facts about corals and reefs.
View our web page that shows coastal imagery and wave characteristics near Adelup Point, Guam.
Below are multimedia items associated with this project.
Coral reef restoration can protect hundreds of millions of dollars of coastal property and business activity annually from storm-driven flooding.
It can protect thousands of people, especially children, the elderly, minorities, and those below the poverty line. Thus, coral reef restoration is a mechanism to provide environmental equity.
Coral reef restoration can protect hundreds of millions of dollars of coastal property and business activity annually from storm-driven flooding.
It can protect thousands of people, especially children, the elderly, minorities, and those below the poverty line. Thus, coral reef restoration is a mechanism to provide environmental equity.
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.
Along reef-lined shores of the Pacific Islands, USGS Research Geologist and Oceanographer Ferdinand Oberle studies how warming surface waters, nutrient runoff, and increasingly powerful storms impact coral reefs.
Along reef-lined shores of the Pacific Islands, USGS Research Geologist and Oceanographer Ferdinand Oberle studies how warming surface waters, nutrient runoff, and increasingly powerful storms impact coral 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.
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
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.
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.
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.
