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Wetlands
Wetlands are submerged or permeated by water either permanently or temporarily and are characterized by plants adapted to saturated soil conditions. Wetlands include fresh and salt water marshes, wooded swamps, bogs, seasonally flooded forest, sloughs any land area that can keep water long enough to let wetland plants and soils develop.
They are the only ecosystem designated for conservation by international convention. They have been recognized as particularly useful areas because:
- they absorb the impact of hydrologic events such as large waves or floods;
- they filter sediments and toxic substances;
- they supply food and essential habitat for many species of fish, shellfish, shorebirds, waterfowl, and furbearing mammals;
- they also provide products for food (wild rice, cranberries, fish, wildfowl), energy (peat, wood, charcoal), and building material (lumber);
- they are valuable recreational areas for activities such as hunting, fishing, and birdwatching.
In the past, wetlands were considered wasteland, and many of southern Canada's wetlands were drained or filled in so that they could be farmed or built upon. Recently the value of wetlands has been recognized and efforts have been made to protect these ecosystems. However, they are still disappearing under the pressure of human activity, and are being threatened by air pollution and climate change.
Options to prevent further loss of wetlands include the following:
- adding sediment to coastal wetlands to keep up with rising sea levels;
- planting grasses to protect coastal sands from erosion;
- building dikes or barrier islands;
- controlling water levels artificially;
- developing a national policy of protection.
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