Realms of refuge and recreation
Wetlands such as marshes, swamps, and bogs host animals ranging from amphibians and fish to large mammals. Birds, wetlands’ most conspicuous creatures, use these refuges for nesting,
permanent homes, and stopovers during migration. Wetlands also aid human endeavour. They trap nutrients and purify water by filtering out pollutants. They store rainfall and runoff, preventing flooding and shoreline erosion. Wetlands provide food (wild rice, cranberries, fish, wildfowl), energy (peat, wood, charcoal), and building material (lumber). Finally, wetlands are valued for recreation. Wetlands cover 6 percent of the world’s surface. Canada holds a quarter of these wetlands, which occupy 1.27 million square kilometres, an area surpassed only by Russia’s 1.5 million square kilometres. Wetlands exist in all provinces and territories, but the greatest number dot the Boreal Shield and Hudson Bay Lowlands. Here, bogs (also called muskeg) absorb carbon dioxide, storing it in thick layers of peat. This counters the impact of greenhouse gases produced by humans. An estimated 25 percent of the world’s carbon may be locked up in the peat bogs of Canada’s boreal forests.
Protecting the wetlands
In Canada, wetlands are in retreat. Most losses are due to agricultural expansion. Wetland areas hardest hit include the Fraser River delta (80 percent gone), the Prairies potholes region (71 percent), the lower Great Lakes and the St. Lawrence Valley (70 percent), and Atlantic coastal marshes (65 percent). In 1981, Canada entered into the Ramsar Convention, an international accord on wetlands protection, to stem further losses. Across Canada, 36 Ramsar sites protect 13 million hectares of wetlands.
This animation contains three diagrams of the three basic forms of wetlands: marshes, swamps and bogs. Hovering over an image reveals its name; clicking on it opens a text box with details.