• A great blue heron wades through a marsh near Ottawa, ON. (Photo: David White/CanGeo Photo Club)

Every year on February 2nd, the world comes together to celebrate the importance of wetlands, which are the only ecosystem designated for conservation by international convention. World Wetlands Day marks the anniversary of the adoption of the Ramsar Convention (formerly the Convention on Wetlands of International Importance), named for the city of Ramsar, Iran, where it was signed in 1971.

Currently 169 nations, including Canada, are contracting members of the convention, which means they have committed to protecting wetlands within their borders as well as raising public awareness about the importance of wetlands.

In honour of World Wetlands Day 2016, here are seven facts you may not know about these vital ecosystems.

1. Wetlands make up 14 per cent of Canada's landmass

A green frog at Grindstone Marsh Trail in Hamilton, ON. (Photo: Miguel Low Foon/CanGeo Photo Club)

Unfortunately, wetlands were once considered wasteland and often drained or filled in to create farmland or suburbs. Agricultural expansion is responsible for 85 per cent of Canada's wetland loss. In southern Ontario alone, more than 70 per cent of wetlands have disappeared, gobbled up by roads, farmland, housing and industry.

2. There are many different kinds of wetlands

A foggy fall morning in Orillia, ON. (Photo: Grace Donald/CanGeo Photo Club)

'Wetland' refers to any land that is permanently or temporarily submerged in or permeated with water. By this definition, freshwater and saltwater marshes, wooded swamps, bogs, seasonally flooded forest, sloughs and peatlands are all considered wetland.

3. Canada is divided into seven wetland regions

A mountain wetland in Jasper National Park, AB. (Photo: Ray Fortner/CanGeo Photo Club)

These regions - arctic, subarctic, boreal, prairie, temperate, oceanic and mountain - describe broad climatic/vegetation zones that hew closely to Canada's physical geography.

4. Canada has protected 13 million hectares of wetland

Early morning on the boardwalk at Point Pelee National Park. (Photo: Susan Breau/CanGeo Photo Club)

To date, Canada has designated 37 Ramsar sites, 17 of which are National Wildlife Areas or Migratory Bird Sanctuaries. 90 per cent of Canada's protected wetland lies within National and Provincial parks and other federally-managed areas.

5. Wetlands are a critical part of the water cycle

Lily pads after the rain in Windsor, NS. (Photo: Kristen Dunlop/CanGeo Photo Club)

Wetlands help moderate river flow, taking on excess water during floods and maintaining flow in dry years. Wetlands also recharge groundwater, and clean and remediate polluted water.

6. Animals rely on wetlands

A marsh wren in the reeds. (Photo: Justin Ohata/CanGeo Photo Club)

From the tiniest zooplankton to massive mammals, wetlands are teeming with life. The water's surface and the wetland bottom are covered with insect eggs, larvae, and nymphs, which are important parts of the food chain. Fish, amphibians, and reptiles all depend on the habitat provided by wetlands, and numerous birds and mammals make use of the water and shoreline.

7. So do humans

Birdwatching at Oak Hammock Marsh in Manitoba. (Photo: Cailin Hodder/CanGeo Photo Club)

In addition to providing space for recreational activities like hunting, fishing and birdwatching, they also provide products for food (wild rice, cranberries, fish, wildfowl), energy (peat, wood, charcoal), and building material (lumber).