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Wetlands

 

Overview

Heated controversy has surrounded attempts to preserve wetlands. For decades, many thought wetlands were mucky, mosquito-infested places and drained them to use as farmland, industrial sites, or residential areas. Fewer than half as many acres of wetlands remain in the continental United States compared with when the first European settlers arrived about 500 years ago. Now, wetlands are recognized as important wildlife refuges and water purification systems. Wetlands are areas that have standing water for at least part of the year. Marshes, swamps, tidal flats and associated pools, bayous, and bogs are the most common. Marshes are water-saturated, poorly drained areas with both aquatic and grasslike plants. Swamps, unlike marshes, have trees and bushes. Water flows into swamps and marshes from streams, or even an ocean. Bogs are waterlogged, spongy ground in former lakes now filled with living and dead mosses, which eventually become peat. Wetlands are important for many reasons. They support a large volume of plants, which in turn supply cover and food for animals. Wetlands retain water like a giant sponge - flowing water is slowed as it passes through and is absorbed by plants and soils. By soaking up the water, wetlands not only prevent floods but make water available during a drought. They also help reduce the threat of low salinities in coastal waters. Wetlands can also clean up contaminated water. Organisms and soils in a wetland act as a filter for fertilizers and other pollutants. Algae and bacteria break down mineral and organic matter, which can then be used as food for plant life. Some municipalities use wetlands as the final stage in treating waste from sewage treatment plants. Other communities are actually constructing wetlands for this purpose. However, wetlands can't perform miracles. They can be ruined by too much waste. Because the economic and health benefits of wetlands are now well known, Congress has passed several laws protecting them. However, in many areas developers want to build on the land, farmers want to cultivate it, and oil companies want to remove the oil under the ground. As long as our population keeps growing, the struggle over what will become of the wetlands will continue.

Activity

(Note: This activity should be done before the first frost of fall or after spring thaw.) Wetlands are important habitats for animals. One kind of animal that you might not think to look for there is insects. Yet there are more species of insects than of all the other animal species combined, and they live in almost all known habitats on earth. You can find insects in any body of water, unless it’s very polluted. Materials
  • kitchen strainer
  • jars
  • insect net (optional)
  • magnifying glass
  • field guide to insects
  • notebook
  • pencil
1. Go to a nearby body of water. Before you do any collecting, look around. What wildlife do you see? Do you notice any insects? 2. Draw or write about any insects that you see. Look them up in your field guide. Can you identify them? 3. See if you can catch any insects. Put them in a jar to take back to the classroom. 4. Now look in the water. What wildlife do you see? Do you notice any insects? 5. Pull your strainer through the water and look at what animals you catch. If it isn't a fish or polliwog, chances are it's an insect. Put any insects you catch in a jar with some water. 6. Draw or write about the insects you caught. Were there any you could see that you couldn't catch? Look them up in your field guide. Can you identify them? 7. Chances are that many of the insects you see in the water are larval stages of the insects you see on land and in the air. Many insects start their lives in water and then move out of the water as they mature. Can you figure out which of the insects you caught in the water are an earlier stage of the same insects you saw on land? 8. Take the insects you caught back to the classroom and try to identify them more clearly. See what else you can learn about them. Questions
  1. How would the food chain change if many insects didn't have aquatic life-history stages?

Resources

    Levantines, L. (1995, July-Aug) Science gets swamped. Audubon, p. 112.
    Lewis, W.M., Jr. (1996, July) Wetlands on the line. Geotimes, p. 5.
    (This issue includes other articles on wetlands)
    Manks, M. (1996, June-July) The beauty of wetlands. National Wildlife, p. 20.
    Niering, W.A. (1985) Wetlands: The Audubon Society Guides. New York:
    Alfred A. Knopf, Inc.
    Rood, R. (1994) Wetlands. New York: Harper Collins.
    Rybolt, T.R. & Mebane, R.C. (1993) Environmental experiments about life.
    Hillside, NJ: Enslow Publishers, Inc.
    U.S. Fish and Wildlife Service?national wetlands inventory:
    http://www.nwi.fws.gov/
    Wetnet (includes virtual bird tour):
    http://www.wetlands.ca/
    Ducks Unlimited
    1 Waterfowl Way
    Memphis, TN 38120
    (901) 758-3825