Impact Area

What is a wetland?

Wetlands are a natural defence system for drought, floods and climate change.

Canada’s wetlands are diverse. They appear on the prairies, in the boreal forest, along coastlines and even in the tundra, helping to keep our communities healthy and safe.

They protect us from flooding, drought and help mitigate the impacts of climate change. They are vital for wildlife by providing important habitat for feeding, resting and raising young.

Wetlands are defined as land that is saturated with water long enough to promote wetland or aquatic processes as indicated by poorly drained soils, vegetation and other biological activity adapted to a wet environment.  (National Wetlands Working Group 1997).

Wetland plants absorb carbon dioxide as they grow. When they die, that carbon doesn’t get released back into the atmosphere. © Ducks Unlimited Canada

They protect us from flooding, drought and climate change. They protect wildlife by providing hundreds of species with safe places to eat, sleep and raise young. They give us natural places to play, learn and explore. They also clean the water we enjoy at beaches, lakes and rivers.

Educator resources

Types of wetlands

Canada’s wetlands can be broadly grouped into two categories: organic and mineral. Within these categories, they are further grouped into five classes: bog, fen, swamp, marsh, and shallow water wetlands.

Organic wetlands

Organic wetlands are known as peatlands (or muskeg) and include bogs and fens and sometimes swamps. These wetlands have accumulated 40 cm or more of organic material (peat).

Bogs

Bogs are peatlands with over 40 cm of accumulated peat, averaging 3 to 5 m, and with some exceptional cases reporting up to 10 m.

Fens

Fens are peatlands with over 40 cm of accumulated peat that is primarily composed of sedge and brown moss plant materials.

Mineral wetlands

Mineral wetlands include swamps, marshes and shallow water. Mineral wetlands are characterized by saturated (wet) soils resulting in gleying (blue-grey colour) and mottling (red or brown mottles). There may be some organic material (peat) accumulation, but it is a thin layer less than 40 cm thick.

Marshes

Marshes are mineral wetlands with areas of shallow water that tend to fluctuate (change up and down), daily, seasonally or even annually.

Swamps

Swamps, sometimes called thickets, are dominated by either trees or tall shrubs.

Shallow open-water wetlands

Shallow water wetlands, which may also be referred to as ponds, shallow lakes, oxbows and sloughs, are a distinct class of mineral wetlands.

Salt marsh

Salt marshes are tidal wetlands typically found in the upper intertidal zone between mean sea level and high tide, where salt- and flood-tolerant vegetation can grow.

How wetlands work

Wetlands act like sponges: soaking up rain and melted snow, and slowly releasing water during drier seasons.
Wetlands clean our water: acting as natural filters, they slowing the flow of water, so bacteria, algae and plants can break down contaminants, which are then removed by sedimentation.
Wetlands trap and store carbon: capturing carbon in plants and soil instead of releasing it into the atmosphere as carbon dioxide.
Wetlands offer critical wildlife habitat: giving many species places to rest, feed and raise young.

This graphic demonstrates how wetlands work and the many benefits they provide for the health of our environment.

How wetlands work? Wetlands act like sponges, soaking up rain and melted snow, and can slowly release water during drier seasons.

What we do

We are building on the momentum of our successes—working with our supporters to protect and restore Canada’s wetlands.

Estimates put 25 per cent of the world’s remaining marshes, bogs, swamps and other cattail-lined, carbon-rich water bodies inside Canada’s borders. Our understanding of wetlands is growing, but they continue to be lost.

In southern areas of Canada, up to 70 per cent of our wetlands have already been destroyed or degraded and up to 95 per cent in densely populated areas. As they continue to disappear, so too do the many benefits they provide.

Putting wetlands on the map: Since 1979, Ducks Unlimited Canada has used aerial photography and satellite imagery to map and inventory millions of acres of wetlands across Canada. In 2002, we started advocating for a national wetland inventory and monitoring system and, with the support of 150-plus conservation partners, have built a database — the Canadian Wetland Inventory.