Wetland

Where the Land Is Wet

Wetland environments are any flooded or water-soaked area with a covering of water plants. A wetland is classified by the plant species that live in it. What types of plants grow depend on how fast the water in the wetland flows. Some wetlands are like a swiftly flowing river, while others are like a thick sponge. The world’s major wetlands are located in southern Africa, North America, central South America, and Asia. The largest wetlands in the world are the bogs of the Siberian lowlands in Russia. They cover 600,000km2. That’s three times the size of Great Britain. All the world’s wetlands, even the large Siberian bogs, are endangered environments.

Wetlands

Wetlands are an important habitat for many bird species.Some of these species live year-round in wetlands. Others use several different wetlands along their migration route when traveling between their winter and summer grounds.

©G.Ellis/GLOBIO.org

Bogs, Marshes, and Swamps, Oh My!

Wetlands are found in nearly every region of the world. Types of wetlands include swamps, bogs, marshes, estuaries, and fens. In different areas, they may have different local names. For example, bogs are located in colder, temperate climates. You’ll find bogs in Finland, northern Germany, Scotland, Denmark, Estonia, and the Falkland Islands. Canada has bogs, too, but Canadians call them muskegs. In the southeastern United States, swamps are called bayous.

Keep That Water Clean

About one-third of all the water that evaporates from the ocean falls on the land as rain and snow. This is the water that fills rivers, lakes, swamps, marshes, and other wetlands. Wetlands filter and maintain much of the freshwater humans and other animals depend on. This makes wetlands one of the most important environments.

Only Soggy Sometimes

Not all wetlands are wet all year. The pantanal in southern Brazil is a large flat wetland. It is covered by 1m of water part of the year and is dry and spongy the rest of the year. Plants and animals in the wetlands must be able to adapt to seasonal changes.

Cormorants

Cormorants are sea birds that often fish in estuaries, which are salty wetlands found close to oceans.

©M.Wilhelm/GLOBIO.org

Wetlands With a Dash of Salt

Another type of wetland is an estuary or salt marsh.These wetlands are where freshwater and seawater mix. The plants and animals living here must adapt to many changes to survive. Estuaries are places where four conditions meet – freshwater, seawater, land, and air. These conditions allow for a great diversity of plant and animal life. This biodiversity is equal to or greater than that found in a tropicalrainforest. The unique habitat of an estuary makes a great home for animals that spend part of their lives in salt water and part of their lives in freshwater, like the salmon. Chesapeake Bay on the east coast of the USA is the largest estuary in the world.

Where Did the Dinosaurs Roam? Ancient Wetlands!

Alligators and Crocodiles

Alligators and crocodiles are found in warmer, more tropical wetland areas on several continents. Animals like these spend time in water and on land. They are responsible for carrying plants and their seeds to new areas where they can grow and spread.

©G.Ellis/GLOBIO.org

Wetlands have been an important part of life on Earth for millions of years. Many dinosaur species depended on wetlands and the plants growing there for food and safety. Today, scientists find some of the best-preserved dinosaur fossils in ancient wetlands. A few dinosaur relatives still live in tropical wetlands. These include crocodiles, caimans, and alligators.

Layers of a Wetland

Wetlands are really interesting places. They are rich in diversity and are where land and water environments meet and mix.

Discover more about what makes a wetland interesting by clicking below.

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©G.Ellis/GLOBIO.org

A Great Place to Call Home

Wetlands provide habitat for a great number of water and land species. They are also an important environment to many migratory bird species. These birds use them on their way to and from their winter and summer grounds. Almost half of all threatened and endangered species in North America rely on wetlands.

Who Lives in a Wetland?

Fish, frogs, water birds, and insects are found in wetlands on every continent. There are also some fascinating creatures that live only in specific wetlands. In South America, capybara, the world’s largest rodents, are found in wetlands. In Africa, flamingoes, hippos, lechwe antelope, fish eagles, and Nile crocodiles all need wetlands. In the South Pacific, wetlands are home to reptiles like snake necked and pig nosed turtles and freshwater crocodiles. American beavers help create and maintain North American wetlands used by ducks, bald eagles, and moose. Wetlands in the grasslands are critical habitat for millions of geese, ducks, and wading birds such as herons. In the southeast USA, swamps are home to alligators, anhingas, and endangered Florida panthers.

Ducks

Different species of ducks are found in most wetlands around the world. Ducks have webbed feet that make them great swimmers. They also have special sieve-like bills for pushing water out of their mouths while keeping little plants and arthropods in.

©M.Wilhelm/GLOBIO.org

Arthropods at the Beginning

Arthropods are some of the wetlands’ most important creatures. They take advantage of the many different niches a wetland environment creates. Arthropods are also at the beginning of the food chain. This means they help support all kinds of other life, from fishes and frogs to birds and crocodiles.

Wetlands and People

Very few people live in wetlands. In Iraq, the Ma’dan, or Marsh Arabs, learned to build mudhif - distinctive cathedral-shaped reed houses. They fished and lived in the large wetlands east of An Nasiriyah. But the Ma’dan, who inhabited these areas for thousands of years, no longer live there. Habitat destruction poses serious threats not only to native peoples but also to the area's wildlife populations. New conservation projects are working to restore the marsh for the Ma’dan and the wildlife.

Wetlands Are Not Wastelands

People once viewed wetlands as wasted land. For most of the past one hundred years, people have been draining the water from wetlands and filling them in. They then build houses, cities, and roads where the wetlands used to be. Thousands of areas have been drained and converted to farms, too. Pollution from chemicals, fertilizers, and other sources poses another threat to wetlands. Some scientists estimate that the world may have lost up to 50% of all wetlands since 1900. The remaining wetlands are in danger of degradation or are currently degraded.

Pollution harming wetlands

Almost all wetlands are degraded or in danger of becoming degraded. Air and water pollution damage many wetland areas, especially those near factories and industrial plants. Many wetlands have also been drained and destroyed in order to build houses and cities. Wetlands are not only homes for millions of species, but they also help keep the world’s water clean.

©G.Ellis/GLOBIO.org

Protect Them!

Fortunately, people are discovering how important wetlands are to the health of the environment that surrounds the wetland. Many countries now have laws to protect wetlands, and they are working to protect even more. The Ramsar Convention is an international treaty that has been signed by 146 parties for the wise use of wetlands and their resources. The Convention has been critical to the protection of wetlands for migrating water birds.

Plants

There are many plant species that have special adaptations for living in wetland environments. These plants are very good at living where the ground is soaked with water. Many of them have adapted to taking in nutrients from the water, which keeps them healthy and the water clean.

©G.Ellis/GLOBIO.org