What is a Wetland?
Meet Wet Wally. This know-it-all frog is here to answer your questions about wetlands.
What's a wetland, Wet Wally?
That's easy. Take some low-lying land, add water, mix in lots of plants and animals, and you have a wetland!
So wetlands are always wet, right?
Wetlands are places where there is shallow water or very soggy soil at least part of the time. Plants that grow there love having wet "feet" (roots).
Are all wetlands the same?
No way! Most folks think of three major wetland groups: swamps, marshes, and bogs. It’s easy to tell the difference between the first two. Swamps have mostly trees or shrubs. And marshes have mostly grassy plants. Bogs are spongy, mossy wetlands where plants pile up faster than they can rot away. All those plants form thick layers of peat.
Lakes are wet. Aren't they wetlands, too?
Not really—they're too wet. Remember wet-footed plants? Well, lakes are mostly too deep for plants to grow right up out of them. That goes for oceans and most ponds, rivers, and streams, too. But the edges of these bodies of water and waterways ... now that’s a different story.
The edges are where the water is often shallow enough — or the soil just soggy enough — for wetland plants to take hold. But you can also find wetlands far from any deep water. Mountains may have low spots where water collects. And water seeping up from underground can make a wetland — even in a desert.
What's so important about wetlands?
Ah, glad you asked. Without wetlands, thousands of species of animals and plants would become extinct. And floods and pollution would be much worse. Oh, I tell you wetlands are greatly misunderstood.
How so, Wet Wally?
People have often thought of wetlands as smelly, buggy wastelands. They've drained the water from them, making dry land for farms, houses, and shopping malls. Today more than half of the wetlands in the "lower 48" states have been destroyed.
But here's the good news: Many other people know that wetlands are wonderlands that we — and thousands of other species — could never do without.
Check out these fascinating facts about wetlands.
- Need Those Wet Spots. More than one-third of the endangered and threatened animals and plants in the United States depend on wetlands in some way. These species may die out if more of their wet places are destroyed. These species include whooping cranes, red wolves, Florida panthers, mission blue butterflies, and green pitcher plants.
- Dry Wetlands? Some wetlands are covered with water for only two or three weeks each year. But they are important as "fast-food restaurants" for ducks and geese flying north in spring. When the birds stop to rest, they fill up on the seeds and small creatures in the water. Many frogs also lay their eggs in wetlands that dry up by the end of summer.
- Swamp Cities. Did you know that parts of some big cities in the United States were built where wetlands used to be? Here are three: Boston, Massachusetts; San Francisco, California; and Washington, D.C.
- On Shaky Ground. Now people realize that filling wetlands with soil and then building on them is a bad idea. For example, the Jefferson Memorial in Washington, D.C., has sunk a bit because it was built on soft ground. And some parts of San Francisco are especially dangerous during earthquakes because the ground isn't firm where the wetlands were. It’s much better not to build on wetlands in the first place.
- Comet Zap. As many as 100,000 wetlands from Delaware to Florida were probably carved out by stuff falling from outer space. Some scientists think the wetlands were formed about 10,000 years ago when pieces of a comet or meteorite struck the Earth. Before long, the holes filled with water. Instant wetlands!
- Big and Wet. Two-thirds of all wetlands in the United States are in Alaska.