A white heron flying across a marsh in York County, Virginia.
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
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...
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...
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...
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...
A white heron flying across a marsh in York County, Virginia.
Brown patches and brown stems show stress in this phagmites (roseau cane) stand in Pass A Loutre Wildlife Management Area, a tract of state-owned land in Louisiana's bird foot delta, where the Mississippi River meets the Gulf of Mexico. An ongoing phragmites was first discovered in spring 2017 and blamed on an invasive scale insect from Asia.
Brown patches and brown stems show stress in this phagmites (roseau cane) stand in Pass A Loutre Wildlife Management Area, a tract of state-owned land in Louisiana's bird foot delta, where the Mississippi River meets the Gulf of Mexico. An ongoing phragmites was first discovered in spring 2017 and blamed on an invasive scale insect from Asia.
- Wetlands are hotspots for mercury methylation and export of methylmercury to aquatic foodwebs.
- Rice is the most abundant wetland type in California and globally in temperate and tropical latitudes.
- Wetlands are hotspots for mercury methylation and export of methylmercury to aquatic foodwebs.
- Rice is the most abundant wetland type in California and globally in temperate and tropical latitudes.
--The South Bay Salt Pond Restoration Project
By Laura Valoppi, Lead Scientist
--The South Bay Salt Pond Restoration Project
By Laura Valoppi, Lead Scientist
Slideshow of images related to USGS wetlands research.
Slideshow of images related to USGS wetlands research.
This video describes causes of wetland loss in the Mississippi River Delta.
This video describes causes of wetland loss in the Mississippi River Delta.
Wetlands in the prairie pothole region of North American, while often appearing as being isolated from each other, are interconnect to each through a variety of ways including temporary surface-water flows, long-term groundwater flows, and biotic movements.
Wetlands in the prairie pothole region of North American, while often appearing as being isolated from each other, are interconnect to each through a variety of ways including temporary surface-water flows, long-term groundwater flows, and biotic movements.
This video describes research being conducted by Dr. Karen McKee, USGS Research Ecologist, and her university partner, Dr. Julia Cherry. Their goal is to better understand the effects of sea-level rise and other global change factors on coastal wetlands in the Mississippi River Delta. This region contains over 40% of the U.S.
This video describes research being conducted by Dr. Karen McKee, USGS Research Ecologist, and her university partner, Dr. Julia Cherry. Their goal is to better understand the effects of sea-level rise and other global change factors on coastal wetlands in the Mississippi River Delta. This region contains over 40% of the U.S.
This video describes research conducted by Dr. Karen McKee, USGS Research Ecologist, and her university partners, Dr. Irv Mendelssohn (Louisiana State University) and Dr. Mark Hester (University of Louisiana). They are studying the effects of hurricanes on marsh and mangrove wetlands in the Mississippi River Delta, which contains over 40% of the U.S.
This video describes research conducted by Dr. Karen McKee, USGS Research Ecologist, and her university partners, Dr. Irv Mendelssohn (Louisiana State University) and Dr. Mark Hester (University of Louisiana). They are studying the effects of hurricanes on marsh and mangrove wetlands in the Mississippi River Delta, which contains over 40% of the U.S.
USGS scientists deliver a variety of science in the effort to restore wetlands to over 25,000 acres in San Francisco Bay. "Wetland Revival" shows how science is contributing to the transformation of once industrial salt producing ponds into more natural habitat. The program was completed in 2008. USGS General Information Product 61.
USGS scientists deliver a variety of science in the effort to restore wetlands to over 25,000 acres in San Francisco Bay. "Wetland Revival" shows how science is contributing to the transformation of once industrial salt producing ponds into more natural habitat. The program was completed in 2008. USGS General Information Product 61.
Long Island marsh water
Long Island marsh water
Dr. Lee Foote, National Wetlands Research Center, studies a Louisiana marshland.
Dr. Lee Foote, National Wetlands Research Center, studies a Louisiana marshland.
Knowledge gaps and opportunities in water-quality drivers of aquatic ecosystem health
Everglades Depth Estimation Network (EDEN)—A decade of serving hydrologic information to scientists and resource managers
Desert wetlands—Archives of a wetter past
Trends and causes of historical wetland loss in coastal Louisiana
Wetland fire remote sensing research--The Greater Everglades example
Integrated monitoring of ecological conditions in wetland-upland landscapes
The Cottonwood Lake study area, a long-term wetland ecosystem monitoring site
Methods for processing and imaging marsh foraminifera
USGS research on Florida's isolated freshwater wetlands
Estuaries of the Greater Everglades Ecosystem: Laboratories of Long-term Change
Hydrology and Ecology of Freshwater Wetlands in Central Florida - A Primer
Potential consequences of saltwater intrusion associated with Hurricanes Katrina and Rita
Related Content
- FAQ
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...
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...
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...
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...
- Multimedia
White Heron in Marsh
A white heron flying across a marsh in York County, Virginia.
A white heron flying across a marsh in York County, Virginia.
High stakes, big questions in marsh grass die-backHigh stakes, big questions in marsh grass die-backBrown patches and brown stems show stress in this phagmites (roseau cane) stand in Pass A Loutre Wildlife Management Area, a tract of state-owned land in Louisiana's bird foot delta, where the Mississippi River meets the Gulf of Mexico. An ongoing phragmites was first discovered in spring 2017 and blamed on an invasive scale insect from Asia.
Brown patches and brown stems show stress in this phagmites (roseau cane) stand in Pass A Loutre Wildlife Management Area, a tract of state-owned land in Louisiana's bird foot delta, where the Mississippi River meets the Gulf of Mexico. An ongoing phragmites was first discovered in spring 2017 and blamed on an invasive scale insect from Asia.
Mercury and Rice in the California Delta: Lessons Linking Wetlands to Water to WildlifeMercury and Rice in the California Delta: Lessons Linking Wetlands to Water to WildlifeMercury and Rice in the California Delta: Lessons Linking Wetlands to Water to Wildlife- Wetlands are hotspots for mercury methylation and export of methylmercury to aquatic foodwebs.
- Rice is the most abundant wetland type in California and globally in temperate and tropical latitudes.
- Wetlands are hotspots for mercury methylation and export of methylmercury to aquatic foodwebs.
- Rice is the most abundant wetland type in California and globally in temperate and tropical latitudes.
PubTalk 5/2012 — Restoring the Wild Heart of South San Francisco BayPubTalk 5/2012 — Restoring the Wild Heart of South San Francisco BayPubTalk 5/2012 — Restoring the Wild Heart of South San Francisco Bay--The South Bay Salt Pond Restoration Project
By Laura Valoppi, Lead Scientist
--The South Bay Salt Pond Restoration Project
By Laura Valoppi, Lead Scientist
Wade into Wetlands ResearchSlideshow of images related to USGS wetlands research.
BySlideshow of images related to USGS wetlands research.
BySea-Level Rise, Subsidence, and Wetland LossThis video describes causes of wetland loss in the Mississippi River Delta.
ByThis video describes causes of wetland loss in the Mississippi River Delta.
ByWetlands in the prairie pothole region of North AmericanWetlands in the prairie pothole region of North AmericanWetlands in the prairie pothole region of North American, while often appearing as being isolated from each other, are interconnect to each through a variety of ways including temporary surface-water flows, long-term groundwater flows, and biotic movements.
Wetlands in the prairie pothole region of North American, while often appearing as being isolated from each other, are interconnect to each through a variety of ways including temporary surface-water flows, long-term groundwater flows, and biotic movements.
Effects of Sea-Level Rise on Coastal Wetlands in the Mississippi DeltaEffects of Sea-Level Rise on Coastal Wetlands in the Mississippi DeltaEffects of Sea-Level Rise on Coastal Wetlands in the Mississippi DeltaThis video describes research being conducted by Dr. Karen McKee, USGS Research Ecologist, and her university partner, Dr. Julia Cherry. Their goal is to better understand the effects of sea-level rise and other global change factors on coastal wetlands in the Mississippi River Delta. This region contains over 40% of the U.S.
This video describes research being conducted by Dr. Karen McKee, USGS Research Ecologist, and her university partner, Dr. Julia Cherry. Their goal is to better understand the effects of sea-level rise and other global change factors on coastal wetlands in the Mississippi River Delta. This region contains over 40% of the U.S.
Coastal Louisiana: Impacts of Hurricanes on Salt Marsh and Mangrove WetlandsCoastal Louisiana: Impacts of Hurricanes on Salt Marsh and Mangrove WetlandsCoastal Louisiana: Impacts of Hurricanes on Salt Marsh and Mangrove WetlandsThis video describes research conducted by Dr. Karen McKee, USGS Research Ecologist, and her university partners, Dr. Irv Mendelssohn (Louisiana State University) and Dr. Mark Hester (University of Louisiana). They are studying the effects of hurricanes on marsh and mangrove wetlands in the Mississippi River Delta, which contains over 40% of the U.S.
This video describes research conducted by Dr. Karen McKee, USGS Research Ecologist, and her university partners, Dr. Irv Mendelssohn (Louisiana State University) and Dr. Mark Hester (University of Louisiana). They are studying the effects of hurricanes on marsh and mangrove wetlands in the Mississippi River Delta, which contains over 40% of the U.S.
Wetland RevivalUSGS scientists deliver a variety of science in the effort to restore wetlands to over 25,000 acres in San Francisco Bay. "Wetland Revival" shows how science is contributing to the transformation of once industrial salt producing ponds into more natural habitat. The program was completed in 2008. USGS General Information Product 61.
ByUSGS scientists deliver a variety of science in the effort to restore wetlands to over 25,000 acres in San Francisco Bay. "Wetland Revival" shows how science is contributing to the transformation of once industrial salt producing ponds into more natural habitat. The program was completed in 2008. USGS General Information Product 61.
ByLong Island marsh waterLong Island marsh water
Long Island marsh water
Studying Louisiana MarshlandDr. Lee Foote, National Wetlands Research Center, studies a Louisiana marshland.
Dr. Lee Foote, National Wetlands Research Center, studies a Louisiana marshland.
- Publications
Filter Total Items: 13
Knowledge gaps and opportunities in water-quality drivers of aquatic ecosystem health
This report identifies key scientific gaps that limit our ability to predict water quality effects on health of aquatic ecosystems and proposes approaches to address those gaps. Topics considered include (1) coupled nutrient-carbon cycle processes and related ecological-flow-regime drivers of ecosystem health, (2) anthropogenic and geogenic toxin bioexposure, (3) fine sediment drivers of aquatic eEverglades 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 interpolAuthorsEduardo Patino, Paul Conrads, Eric D. Swain, James M. BeerensDesert 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 ofAuthorsJeffery S. Pigati, Kathleen B. Springer, Craig R. MankerTrends 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 reAuthorsJulie BernierWetland 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 ecosAuthorsJohn JonesIntegrated 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 analyAuthorsAlisa Gallant, Walt SadinskiThe 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 theAuthorsDavid M. Mushet, Ned H. EulissMethods 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, intertidAuthorsChandra A. Dreher, James G. FlocksUSGS 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 numbAuthorsArturo E. Torres, Kim H. Haag, Terrie M. Lee, Patricia A. MetzEstuaries 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-driAuthorsG.L. Wingard, J.W. Hudley, F.E. MarshallHydrology 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 StAuthorsKim H. Haag, Terrie M. LeePotential 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.AuthorsGregory D. Steyer, Brian C. Perez, Sarai C. Piazza, Glenn Suir - News