SVN3M - Water
Notes on Wetlands
(from the Ducks Unlimited website, accessed 01/20/08)
Top Ten Wetland Facts
Wetlands are a vital part of our environment. Unfortunately, when people think of wetlands, many think of them as wastelands. This couldn’t be further from the truth.
1.Wetlands are found all over the world
Wetlands are up there with tropical rainforests for their productivity. They are found all over the world—the only continent that does not have wetlands is Antarctica. Canada is fortunate to be home to more than 1,270,000 square kilometres (127 million hectares) of wetlands. That’s nearly 25 per cent of all the wetlands on Earth!
2.Wetlands keep our water clean
Water quality is one of the most important environmental issues facing Canada and the world at large. As nature’s water filters, wetlands play a key role in keeping our water clean. The many types of plants, bacteria and animals that live in wetlands remove many harmful impurities.
3.Wetlands are valuable wildlife habitat
Wetlands and their surrounding uplands are habitat for approximately 600 species of plants, animals and insects in Canada. This includes mammals, birds, amphibians, reptiles, fish and many invertebrates. These species use wetlands as habitat for food, water, breeding and nesting grounds, resting areas and shelter.
4.Wetlands can help to reduce flooding
Often, spring runoff and heavy rain can cause flooding. There is simply too much water for the landscape to absorb. When wetlands are lost, so is a natural storage area for water. Wetlands can help to reduce the risk and severity of flooding by storing excess water and slowing the flow.
5.Wetlands are great places to have fun
Thanks to their natural beauty and abundant wildlife, wetlands make great places to relax and have fun. Activities like hiking, wildlife watching, hunting, angling, camping and canoeing are just some of the things people do in wetland areas. Visit a wetland near you to see how you can enjoy the great outdoors!
6.Wetlands can help treat wastewater
One of the problems faced by society is how to properly dispose of wastewater and sewage. Wetlands are so good at removing impurities from water that they can help to treat and clean wastewater. In fact, specially constructed treatment wetlands have been used to treat wastewater in Europe for over 50 years. Several communities and businesses in Canada now use wetlands to treat their wastewater.
7.Wetlands make great outdoor classrooms
Wetlands are full of life and they make great places to learn about biology and the environment! They are full of the ‘raw materials’ that make learning fun and effective.
8.Wetlands help to replenish groundwater
As wetlands store excess water, they release it back into the environment. Water held in wetlands seeps slowly back into the ground and is purified and filtered. This supplies people with clean water.
9.Wetlands help to guard against erosion
Thanks to the vegetation found in wetlands, these habitats can help to protect against soil erosion. These plants stabilize the soil, holding it in place against erosive forces. Plants break up waves and currents that would otherwise impact on soil. By trapping sediments found in the water, wetland plants also help to reinforce soils against erosion.
10.Canada’s wetlands continue to disappear
Despite these many benefits that wetlands provide to people and wildlife, they continue to be destroyed across Canada. As much as 70 percent have been lost in some areas of the country.
Wetlands—Nature’s Water Filters
Wetlands are an important feature on Canada’s many landscapes. As part of Canada’s vast water systems, wetlands play the role of nature’s water filter. They have the amazing ability to remove harmful impurities from the water we drink and use every day—long before it reaches the pipes that carry it to our homes.Wetlands exist as part of a watershed. Watersheds are landscape-level systems through which water flows and drains. Lakes, rivers and wetlands—as well as the land that separates them—are all part of these systems.
These systems are very large and complex. As a result, there are lots of ways that water can become polluted from human activity along the way. Wetlands, and the plants, microbes and wildlife that inhabit them, are the filters in this process.
One way that wetlands clean water is to clean out excess nutrients. Nutrients like phosphorus and nitrogen can enter the water system from agriculture and industrial development and can seriously pollute water and harm the life that depends on it.
Research has shown that the sediments and organisms that live in wetlands can trap, breakdown or absorb these nutrients. In fact, up to 92 per cent of phosphorus and 95 per cent of nitrogen draining from the surrounding watershed can be removed from water passing through a wetland! / Another way that wetlands filter water is to trap and absorb harmful bacteria. Because wetlands are full of life, they are home to a very complex food chain. At the bottom of the food chain are the various microbes and bacteria, which invertebrates, such as insects, feed on. That’s why wetlands can filter up to 90 per cent of bacteria in the water.
Wetlands also trap sediments—up to 70 per cent of sediments found in runoff, according to research. This is important because it helps to purify the water, as well as lessen the impact of erosion.
For these reasons, wetlands are known as nature’s finest water filters! In fact, wetlands are so good at this process that specially constructed wetlands have been used to treat wastewater (sewage) in Europe for over 50 years.
Wetlands are a key link in the water system chain. Canadians have made it clear that water is one of our most important environmental issues. Wetland and water conservation is critical if we want to keep our water healthy. The next time you take a drink of water, think about how Canada’s wetlands help to keep our water clean.
Graphic from Natural Resources Canada website, accessed January 23, 2008