Some of the most threatened habitats in the world, yet also the most vital for wildlife and people, wetlands can be found in millions of squares kilometres of stunning scenery or simply in your back garden.

Technically, wetlands are unique ecosystems that are either permanently or seasonally inundated with water, supporting species that are adapted to live there. They’re dynamic, changing with the seasons and over time into different forms.

Often, types of wetland habitat work together as part of an intricate ecosystem, home to a huge diversity of wildlife.

Types of wetland

Learn to recognise some of the most common wetland ecosystems from all over the world here, and their surprising hidden depths.

Rivers and streams

The river with its banks and trees is an iconic setting for childhood stories like Wind in the Willows.

Riverine wetlands are the home of species such as the water vole and otter, as well as waterbirds and vast swathes of invertebrates.

Unfortunately, only 14% of rivers in England and Wales are in a healthy state (or good ecological condition), so there’s still work to be done to keep our rivers healthy.

Ever changing and flowing, these fertile lands have been a symbol of life and prosperity since the time of the ancient Egyptians.


A floodplain is created when a body of water, such as a river or the sea, overflows and submerges the surrounding land. This leaving mineral-rich sediment behind, creating new habitat like salt marsh. Some are well known, such as the Mekong - 70 million people are reliant on the Mekong Basin.

Deltas and estuaries

An estuary is where freshwater and saltwater meet, and often goes hand in hand with river deltas (the surrounding landmass).

Estuaries like the Severn are gateways for migrating wetland species like salmon and the critically endangered European eel. The Severn is also the home of the magnificent Severn bore.

Read more about estuaries

Modern waterways are difficult for eels to navigate, so we are developing ways to help eels and other aquatic species get into and out of our wetland habitats.

In 2019, WWT conservationists worked with Malagasy communities to release the Critically Endangered Madagascar pochard into Lake Sofia, and will continue to make improvements to this habitat.


You may pass a local lake regularly but did you know that more than 140,000 species are known to live in freshwater ecosystems?

Lakes are usually natural features, larger and deeper than ponds. These wetlands are called ‘lacustrine’.


From farmland ponds just waiting for restoration to ancient glacial ‘pingos’ and even your humble garden pond, they’re an incredible and much needed freshwater ecosystem that can support a huge range of bird, amphibian, mammal and invertebrate life.

If you’re up near WWT Caerlaverock, you might find small ephemeral (temporary) ponds that magically fill with life such as tadpole shrimp and natterjack toads.

At Slimbridge, the amount of ditches used by water voles went up from just 250m to over 15 kilometres in just four years thanks to sympathetic ditch management.


Ditches are man-made channels for the purpose of collecting water runoff. The humble ditch might not seem like much - but healthy ditches, both roadside and agricultural, can actually be hotbeds of life.

For example, fenland ditches are one of the last strongholds of the rare great silver water beetle.

Wet grasslands

Lowland wet grassland often occurs on farmland, where areas of the land are periodically flooded. They provide vital nesting habitat for ground-nesters such as lapwing, curlew and black-tailed godwit, all species on the BoCC 4 Red List.

Read more about wet grasslands

Wet grassland has declined more than 40% in the UK since 1930, mostly due to an increase in agricultural intensity and land development.

Steart Marshes is expected to deliver benefits worth up to £3.5 million in the next 10 years.


Historically overlooked, marshes are wetlands populated by mainly herbaceous species (not trees).

They provide natural drainage systems, water cleaning and flood defences for humans. The new formation of coastal salt marshes such as the Steart reserve is already protecting communities from flooding and drought.


Mudflats are coastal wetlands that form in inter-tidal sheltered areas, usually visible during low tide.

Birds like the Critically Endangered Spoon-billed sandpiper will migrate across the world every season, stopping at tidal mudflats like the Yellow Sea in order to reach their breeding grounds. These mudflats act like wetland 'service stations' for migratory birds.

The sport of ‘mudflat hiking’ at the Wadden Sea is becoming more popular in recent years. The word ‘wad’ is Dutch for mudflat.

Peatlands store around a third of the world’s carbon, but their cutting and processing for garden compost releases it back into the atmosphere.

Peat bogs

Peat bogs can come in two forms: raised bogs or blanket bog. Put simply, they form by rainfall filling up peatlands in old depressions, and can take thousands of years. Because the decaying plant matter in peat bogs doesn’t escape, they act as incredible ‘carbon sinks’. Inch for inch, UK wetlands like peat can store more carbon than the Amazon rainforest.

Read more about peat bogs


Highly nutrient-rich and teeming with bio-organic matter, these areas are some of the most fertile landscapes in the world. Yet the fen wetlands that we see today are not as wild, natural or vast as those that covered England a few centuries ago - only 1% of the original fen habitat remains in scraps across our landscape.

Despite less than 1% of the original fen habitats remaining in the UK, these fragments still support an exceptional diversity of wildlife, like the fen raft spider and fen violet.

The secret swamp (or wet woodland) at WWT Castle Espie is small but important, providing habitat for all sorts of fungi, mosses, bats, birds and invertebrates.

Wet woodlands

Wetlands and woodlands come together in harmony. Water loving trees like willow and alder grow tall and tangled, whilst shade-loving water plants grow beneath. Also known as swamps in other parts of the world, their only value was thought to be when drained, but we now understand that they are valuable for all sorts of reasons.

Read more about wet woodlands


Reedbeds provide shelter to shy wetland species. Bittern, eels and water rails prefer wet reedbeds, while bearded reedlings and many invertebrates need a build up of reed stems. Harvest mice weave tennis ball-sized nests in their stalks. They also act as water filters to clean it of heavy metals and organic compounds such as pathogens.

Read more about reedbeds

The reed plants, sediment and bacteria that hang around the rhizomes in very shallow water all work together to provide brilliant natural water filtering.

The Everglades in Florida supports the largest mangrove forest in the western hemisphere.


Mangrove snakes and hummingbirds dart through the branches of these unique trees, whilst corals, fish and crustaceans use their roots as nurseries. According to a NASA study, mangrove forests are incredible at processing carbon, earning them a place as "one of the planet's best carbon scrubbers".

Read more about mangroves

Coral reefs

Did you know that a coral reef is a wetland? They complement mangroves and seagrass beds, to help to protect vulnerable coastal communities around the world from stormy conditions and wave damage, protection that would otherwise have to be paid for by people.

33% of reef-forming corals and more than a third of all marine mammals are threatened with extinction.