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What are wetlands?

Wetlands are transitional areas, sandwiched between permanently flooded deepwater environments and well-drained uplands, where the water table is usually at or near the surface or the land is covered by shallow water. They include mangroves, marshes (salt, brackish, intermediate, and fresh), swamps, forested wetlands, bogs, wet prairies, prairie potholes, and vernal pools. In general terms, wetlands are lands where saturation with water is the dominant factor determining the nature of soil development and the types of plant and animal communities living in the soil and on its surface. The single feature that most wetlands share is soil or substrate that is at least periodically saturated with or covered by water.

Learn more: USGS Wetland and Aquatic Research Center

Related Content

link
Heron wading through wetlands in New Jersey

Why are wetlands important?

Wetlands provide habitat for thousands of species of aquatic and terrestrial plants and animals. Wetlands are valuable for flood protection, water quality improvement, shoreline erosion control, natural products, recreation, and aesthetics. Wetlands are among the most productive habitats on earth providing shelter and nursery areas for commercially and recreationally important animals like fish...

link

Why are wetlands important?

Wetlands provide habitat for thousands of species of aquatic and terrestrial plants and animals. Wetlands are valuable for flood protection, water quality improvement, shoreline erosion control, natural products, recreation, and aesthetics. Wetlands are among the most productive habitats on earth providing shelter and nursery areas for commercially and recreationally important animals like fish...

Learn More
link
Brown Marsh in Southeast Louisiana

What is the Brown Marsh phenomenon?

Sudden marsh dieback events are not uncommon and have occurred in coastal marshes from the Gulf of Mexico to Maine. Brown Marsh is a term given to the unusually rapid and extensive browning of Louisiana’s saltwater marsh grass Spartina alterniflora, commonly known as oyster grass or smooth cordgrass. One of the most severe events occurred in 2000, when over 100,000 hectares (ha) of salt marsh were...

link

What is the Brown Marsh phenomenon?

Sudden marsh dieback events are not uncommon and have occurred in coastal marshes from the Gulf of Mexico to Maine. Brown Marsh is a term given to the unusually rapid and extensive browning of Louisiana’s saltwater marsh grass Spartina alterniflora, commonly known as oyster grass or smooth cordgrass. One of the most severe events occurred in 2000, when over 100,000 hectares (ha) of salt marsh were...

Learn More
link
lone road lined by palm trees on a small flat island, with water from the sea washing over the road

How would sea level change if all glaciers melted?

There is still some uncertainty about the full volume of glaciers and ice caps on Earth, but if all of them were to melt, global sea level would rise approximately 70 meters (approximately 230 feet), flooding every coastal city on the planet. Learn more: USGS Water Science School: Glaciers and Icecaps National Snow and Ice Data Center: Facts about Glaciers U.S. Global Change Research Program: Sea...

link

How would sea level change if all glaciers melted?

There is still some uncertainty about the full volume of glaciers and ice caps on Earth, but if all of them were to melt, global sea level would rise approximately 70 meters (approximately 230 feet), flooding every coastal city on the planet. Learn more: USGS Water Science School: Glaciers and Icecaps National Snow and Ice Data Center: Facts about Glaciers U.S. Global Change Research Program: Sea...

Learn More
link
A cabin along Alaska's Arctic coast was recently washed into the ocean because the bluff it was sitting on eroded away.

What are the long-term effects of climate change?

Scientists have predicted that long-term effects of climate change will include a decrease in sea ice and an increase in permafrost thawing, an increase in heat waves and heavy precipitation, and decreased water resources in semi-arid regions. Below are some of the regional impacts of global change forecast by the Intergovernmental Panel on Climate Change: North America: Decreasing snowpack in the...

link

What are the long-term effects of climate change?

Scientists have predicted that long-term effects of climate change will include a decrease in sea ice and an increase in permafrost thawing, an increase in heat waves and heavy precipitation, and decreased water resources in semi-arid regions. Below are some of the regional impacts of global change forecast by the Intergovernmental Panel on Climate Change: North America: Decreasing snowpack in the...

Learn More
Filter Total Items: 23
WERC sunset over salt marsh wetland
link
White Heron in Marsh
link
Phragmites under stress in Pass A Loutre, Louisiana
link
Photo of former USGS employee Kat Powelson measuring marsh accretion.
link
New England Salt Marsh
link
Marsh wetlands along the Missouri River
link
Nutria in Louisiana wetlands
link
link
ARMI scientists assess the impacts of global change on U.S. wetlands
link
Birds in a wetland
link
Wetland Restoration; Wetland Marsh Restored
link
link
video thumbnail: Wade into Wetlands Research link
video thumbnail: Sea-Level Rise, Subsidence, and Wetland Loss link
Aerial photo of the prairie pothole region of North American
link
video thumbnail: Effects of Sea-Level Rise on Coastal Wetlands in the Mississippi Delta link
video thumbnail: Coastal Louisiana: Impacts of Hurricanes on Salt Marsh and Mangrove Wetlands link
link
Long Island stream with marsh grass on both sides
link
Desert wetland at Point of Rocks Spring
link
great lakes wetlands
link
Filter Total Items: 13

Everglades Depth Estimation Network (EDEN)—A decade of serving hydrologic information to scientists and resource managers

IntroductionThe Everglades Depth Estimation Network (EDEN) provides scientists and resource managers with regional maps of daily water levels and depths in the freshwater part of the Greater Everglades landscape. The EDEN domain includes all or parts of five Water Conservation Areas, Big Cypress National Preserve, Pennsuco Wetlands, and Everglades National Park. Daily water-level maps are interpol
By
Caribbean-Florida Water Science Center (CFWSC)

Desert wetlands—Archives of a wetter past

Scientists from the U.S. Geological Survey (USGS) are finding evidence of a much wetter past in the deserts of the American Southwest using a most unlikely source—wetlands. Wetlands form in arid environments where water tables approach or breach the ground surface. Often thought of as stagnant and unchanging, new evidence suggests that springs and wetlands responded dynamically to past episodes of
By
Climate Research and Development Program, Geosciences and Environmental Change Science Center

Changing Arctic ecosystems--the role of ecosystem changes across the Boreal-Arctic transition zone on the distribution and abundance of wildlife populations

Arctic and boreal ecosystems provide important breeding habitat for more than half of North America’s migratory birds as well as many resident species. Northern landscapes are projected to experience more pronounced climate-related changes in habitat than most other regions. These changes include increases in shrub growth, conversion of tundra to forest, alteration of wetlands, shifts in species’
By
Ecosystems, Wildlife Program, Alaska Science Center

Trends and causes of historical wetland loss in coastal Louisiana

Wetland losses in the northern Gulf Coast region of the United States are so extensive that they represent critical concerns to government environmental agencies and natural resource managers. In Louisiana, almost 3,000 square kilometers (km2) of low-lying wetlands converted to open water between 1956 and 2004, and billions of dollars in State and Federal funding have been allocated for coastal re
By
St. Petersburg Coastal and Marine Science Center

Wetland fire remote sensing research--The Greater Everglades example

Fire is a major factor in the Everglades ecosystem. For thousands of years, lightning-strike fires from summer thunderstorms have helped create and maintain a dynamic landscape suited both to withstand fire and recover quickly in the wake of frequent fires. Today, managers in the Everglades National Park are implementing controlled burns to promote healthy, sustainable vegetation patterns and ecos

Integrated monitoring of ecological conditions in wetland-upland landscapes

Landscapes of interwoven wetlands and uplands offer a rich set of ecosystem goods and services. Managing lands to maximize ecosystem services requires information that distinguishes change caused by local actions from broader-scale shifts in climate, land use, and other forms of global change. Satellite and airborne sensors collect valuable data for this purpose, especially when the data are analy
By
Earth Resources Observation and Science Center, Earth Resources Observation and Science (EROS) Center

The Cottonwood Lake study area, a long-term wetland ecosystem monitoring site

The Cottonwood Lake study area is one of only three long-term wetland ecosystem monitoring sites in the prairie pothole region of North America; the other two are Orchid Meadows in South Dakota and St. Denis in Saskatchewan. Of the three, Cottonwood Lake has, by far, the longest continuous data-collection record. Research was initiated at the study area in 1966, and intensive investigations of the
By
Ecosystems, Northern Prairie Wildlife Research Center

Methods for processing and imaging marsh foraminifera

This study is part of a larger U.S. Geological Survey (USGS) project to characterize the physical conditions of wetlands in southwestern Louisiana. Within these wetlands, groups of benthic foraminifera-shelled amoeboid protists living near or on the sea floor-can be used as agents to measure land subsidence, relative sea-level rise, and storm impact. In the Mississippi River Delta region, intertid
By
St. Petersburg Coastal and Marine Science Center

USGS research on Florida's isolated freshwater wetlands

The U.S. Geological Survey (USGS) has studied wetland hydrology and its effects on wetland health and ecology in Florida since the 1990s. USGS wetland studies in Florida and other parts of the Nation provide resource managers with tools to assess current conditions and regional trends in wetland resources. Wetland hydrologists in the USGS Florida Water Science Center (FLWSC) have completed a numb
By
Water Resources, Caribbean-Florida Water Science Center (CFWSC)

Estuaries of the Greater Everglades Ecosystem: Laboratories of Long-term Change

Restoring the greater Everglades ecosystem of south Florida is arguably the largest ecosystem restoration effort to date. A critical goal is to return more natural patterns of flow through south Florida wetlands and into the estuaries, but development of realistic targets requires acknowledgement that ecosystems are constantly evolving and changing in response to a variety of natural and human-dri
By
Florence Bascom Geoscience Center

Hydrology and Ecology of Freshwater Wetlands in Central Florida - A Primer

Freshwater wetlands are an integral part of central Florida, where thousands are distributed across the landscape. However, their relatively small size and vast numbers challenge efforts to characterize them collectively as a statewide water resource. Wetlands are a dominant landscape feature in Florida; in 1996, an estimated 11.4 million acres of wetlands occupied 29 percent of the area of the St

Potential consequences of saltwater intrusion associated with Hurricanes Katrina and Rita

Hurricanes Katrina and Rita pushed salt water from the Gulf of Mexico well inland into freshwater marsh communities in coastal Louisiana. This paper describes the spatial extent of saltwater intrusion and provides an initial assessment of impacts (salt stress) to coastal marsh vegetation communities.
By
Ecosystems, Wetland and Aquatic Research Center
link

Changes in Rainfall, Temperature Expected to Transform Coastal Wetlands This Century

Changes in rainfall and temperature are predicted to transform wetlands in the Gulf of Mexico and around the world within the century, a new study...

Read Article
link

New Technique Quickly Predicts Salt Marsh Vulnerability

If coastal salt marshes are like savings accounts, with sediment as the principal, all eight Atlantic and Pacific coast salt marshes studied are "in...

Read Article
link

Normal Weather Drives Salt Marsh Erosion

For salt marshes, hurricanes are just another day at the beach.
Read Article
link

Drainage of Prairie Pothole Wetlands Can Increase Flooding and Degrade Ecosystems

The drainage of small wetlands can decrease wildlife habitat and may contribute to flooding in the Prairie Pothole Region (PPR), according to a recent...
Read Article

Related Content

  • FAQ
    link
    Heron wading through wetlands in New Jersey

    Why are wetlands important?

    Wetlands provide habitat for thousands of species of aquatic and terrestrial plants and animals. Wetlands are valuable for flood protection, water quality improvement, shoreline erosion control, natural products, recreation, and aesthetics. Wetlands are among the most productive habitats on earth providing shelter and nursery areas for commercially and recreationally important animals like fish...

    link

    Why are wetlands important?

    Wetlands provide habitat for thousands of species of aquatic and terrestrial plants and animals. Wetlands are valuable for flood protection, water quality improvement, shoreline erosion control, natural products, recreation, and aesthetics. Wetlands are among the most productive habitats on earth providing shelter and nursery areas for commercially and recreationally important animals like fish...

    Learn More
    link
    Brown Marsh in Southeast Louisiana

    What is the Brown Marsh phenomenon?

    Sudden marsh dieback events are not uncommon and have occurred in coastal marshes from the Gulf of Mexico to Maine. Brown Marsh is a term given to the unusually rapid and extensive browning of Louisiana’s saltwater marsh grass Spartina alterniflora, commonly known as oyster grass or smooth cordgrass. One of the most severe events occurred in 2000, when over 100,000 hectares (ha) of salt marsh were...

    link

    What is the Brown Marsh phenomenon?

    Sudden marsh dieback events are not uncommon and have occurred in coastal marshes from the Gulf of Mexico to Maine. Brown Marsh is a term given to the unusually rapid and extensive browning of Louisiana’s saltwater marsh grass Spartina alterniflora, commonly known as oyster grass or smooth cordgrass. One of the most severe events occurred in 2000, when over 100,000 hectares (ha) of salt marsh were...

    Learn More
    link
    lone road lined by palm trees on a small flat island, with water from the sea washing over the road

    How would sea level change if all glaciers melted?

    There is still some uncertainty about the full volume of glaciers and ice caps on Earth, but if all of them were to melt, global sea level would rise approximately 70 meters (approximately 230 feet), flooding every coastal city on the planet. Learn more: USGS Water Science School: Glaciers and Icecaps National Snow and Ice Data Center: Facts about Glaciers U.S. Global Change Research Program: Sea...

    link

    How would sea level change if all glaciers melted?

    There is still some uncertainty about the full volume of glaciers and ice caps on Earth, but if all of them were to melt, global sea level would rise approximately 70 meters (approximately 230 feet), flooding every coastal city on the planet. Learn more: USGS Water Science School: Glaciers and Icecaps National Snow and Ice Data Center: Facts about Glaciers U.S. Global Change Research Program: Sea...

    Learn More
    link
    A cabin along Alaska's Arctic coast was recently washed into the ocean because the bluff it was sitting on eroded away.

    What are the long-term effects of climate change?

    Scientists have predicted that long-term effects of climate change will include a decrease in sea ice and an increase in permafrost thawing, an increase in heat waves and heavy precipitation, and decreased water resources in semi-arid regions. Below are some of the regional impacts of global change forecast by the Intergovernmental Panel on Climate Change: North America: Decreasing snowpack in the...

    link

    What are the long-term effects of climate change?

    Scientists have predicted that long-term effects of climate change will include a decrease in sea ice and an increase in permafrost thawing, an increase in heat waves and heavy precipitation, and decreased water resources in semi-arid regions. Below are some of the regional impacts of global change forecast by the Intergovernmental Panel on Climate Change: North America: Decreasing snowpack in the...

    Learn More
  • Multimedia
    Filter Total Items: 23
    WERC sunset over salt marsh wetland
    link
    White Heron in Marsh
    link
    Phragmites under stress in Pass A Loutre, Louisiana
    link
    Photo of former USGS employee Kat Powelson measuring marsh accretion.
    link
    New England Salt Marsh
    link
    Marsh wetlands along the Missouri River
    link
    Nutria in Louisiana wetlands
    link
    link
    ARMI scientists assess the impacts of global change on U.S. wetlands
    link
    Birds in a wetland
    link
    Wetland Restoration; Wetland Marsh Restored
    link
    link
    video thumbnail: Wade into Wetlands Research link
    video thumbnail: Sea-Level Rise, Subsidence, and Wetland Loss link
    Aerial photo of the prairie pothole region of North American
    link
    video thumbnail: Effects of Sea-Level Rise on Coastal Wetlands in the Mississippi Delta link
    video thumbnail: Coastal Louisiana: Impacts of Hurricanes on Salt Marsh and Mangrove Wetlands link
    link
    Long Island stream with marsh grass on both sides
    link
    Desert wetland at Point of Rocks Spring
    link
    great lakes wetlands
    link
  • Publications
    Filter Total Items: 13

    Everglades Depth Estimation Network (EDEN)—A decade of serving hydrologic information to scientists and resource managers

    IntroductionThe Everglades Depth Estimation Network (EDEN) provides scientists and resource managers with regional maps of daily water levels and depths in the freshwater part of the Greater Everglades landscape. The EDEN domain includes all or parts of five Water Conservation Areas, Big Cypress National Preserve, Pennsuco Wetlands, and Everglades National Park. Daily water-level maps are interpol
    By
    Caribbean-Florida Water Science Center (CFWSC)

    Desert wetlands—Archives of a wetter past

    Scientists from the U.S. Geological Survey (USGS) are finding evidence of a much wetter past in the deserts of the American Southwest using a most unlikely source—wetlands. Wetlands form in arid environments where water tables approach or breach the ground surface. Often thought of as stagnant and unchanging, new evidence suggests that springs and wetlands responded dynamically to past episodes of
    By
    Climate Research and Development Program, Geosciences and Environmental Change Science Center

    Changing Arctic ecosystems--the role of ecosystem changes across the Boreal-Arctic transition zone on the distribution and abundance of wildlife populations

    Arctic and boreal ecosystems provide important breeding habitat for more than half of North America’s migratory birds as well as many resident species. Northern landscapes are projected to experience more pronounced climate-related changes in habitat than most other regions. These changes include increases in shrub growth, conversion of tundra to forest, alteration of wetlands, shifts in species’
    By
    Ecosystems, Wildlife Program, Alaska Science Center

    Trends and causes of historical wetland loss in coastal Louisiana

    Wetland losses in the northern Gulf Coast region of the United States are so extensive that they represent critical concerns to government environmental agencies and natural resource managers. In Louisiana, almost 3,000 square kilometers (km2) of low-lying wetlands converted to open water between 1956 and 2004, and billions of dollars in State and Federal funding have been allocated for coastal re
    By
    St. Petersburg Coastal and Marine Science Center

    Wetland fire remote sensing research--The Greater Everglades example

    Fire is a major factor in the Everglades ecosystem. For thousands of years, lightning-strike fires from summer thunderstorms have helped create and maintain a dynamic landscape suited both to withstand fire and recover quickly in the wake of frequent fires. Today, managers in the Everglades National Park are implementing controlled burns to promote healthy, sustainable vegetation patterns and ecos

    Integrated monitoring of ecological conditions in wetland-upland landscapes

    Landscapes of interwoven wetlands and uplands offer a rich set of ecosystem goods and services. Managing lands to maximize ecosystem services requires information that distinguishes change caused by local actions from broader-scale shifts in climate, land use, and other forms of global change. Satellite and airborne sensors collect valuable data for this purpose, especially when the data are analy
    By
    Earth Resources Observation and Science Center, Earth Resources Observation and Science (EROS) Center

    The Cottonwood Lake study area, a long-term wetland ecosystem monitoring site

    The Cottonwood Lake study area is one of only three long-term wetland ecosystem monitoring sites in the prairie pothole region of North America; the other two are Orchid Meadows in South Dakota and St. Denis in Saskatchewan. Of the three, Cottonwood Lake has, by far, the longest continuous data-collection record. Research was initiated at the study area in 1966, and intensive investigations of the
    By
    Ecosystems, Northern Prairie Wildlife Research Center

    Methods for processing and imaging marsh foraminifera

    This study is part of a larger U.S. Geological Survey (USGS) project to characterize the physical conditions of wetlands in southwestern Louisiana. Within these wetlands, groups of benthic foraminifera-shelled amoeboid protists living near or on the sea floor-can be used as agents to measure land subsidence, relative sea-level rise, and storm impact. In the Mississippi River Delta region, intertid
    By
    St. Petersburg Coastal and Marine Science Center

    USGS research on Florida's isolated freshwater wetlands

    The U.S. Geological Survey (USGS) has studied wetland hydrology and its effects on wetland health and ecology in Florida since the 1990s. USGS wetland studies in Florida and other parts of the Nation provide resource managers with tools to assess current conditions and regional trends in wetland resources. Wetland hydrologists in the USGS Florida Water Science Center (FLWSC) have completed a numb
    By
    Water Resources, Caribbean-Florida Water Science Center (CFWSC)

    Estuaries of the Greater Everglades Ecosystem: Laboratories of Long-term Change

    Restoring the greater Everglades ecosystem of south Florida is arguably the largest ecosystem restoration effort to date. A critical goal is to return more natural patterns of flow through south Florida wetlands and into the estuaries, but development of realistic targets requires acknowledgement that ecosystems are constantly evolving and changing in response to a variety of natural and human-dri
    By
    Florence Bascom Geoscience Center

    Hydrology and Ecology of Freshwater Wetlands in Central Florida - A Primer

    Freshwater wetlands are an integral part of central Florida, where thousands are distributed across the landscape. However, their relatively small size and vast numbers challenge efforts to characterize them collectively as a statewide water resource. Wetlands are a dominant landscape feature in Florida; in 1996, an estimated 11.4 million acres of wetlands occupied 29 percent of the area of the St

    Potential consequences of saltwater intrusion associated with Hurricanes Katrina and Rita

    Hurricanes Katrina and Rita pushed salt water from the Gulf of Mexico well inland into freshwater marsh communities in coastal Louisiana. This paper describes the spatial extent of saltwater intrusion and provides an initial assessment of impacts (salt stress) to coastal marsh vegetation communities.
    By
    Ecosystems, Wetland and Aquatic Research Center
  • News
    link

    Changes in Rainfall, Temperature Expected to Transform Coastal Wetlands This Century

    Changes in rainfall and temperature are predicted to transform wetlands in the Gulf of Mexico and around the world within the century, a new study...

    Read Article
    link

    New Technique Quickly Predicts Salt Marsh Vulnerability

    If coastal salt marshes are like savings accounts, with sediment as the principal, all eight Atlantic and Pacific coast salt marshes studied are "in...

    Read Article
    link

    Normal Weather Drives Salt Marsh Erosion

    For salt marshes, hurricanes are just another day at the beach.
    Read Article
    link

    Drainage of Prairie Pothole Wetlands Can Increase Flooding and Degrade Ecosystems

    The drainage of small wetlands can decrease wildlife habitat and may contribute to flooding in the Prairie Pothole Region (PPR), according to a recent...
    Read Article