Wetland Biomes:
Essential and
Endangered
1 videocassette 26 minutes
Copyright MCMXCVIII
Rainbow Educational Media
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Raleigh, NC 27616-3177
Distributed by:
United Learning
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CREDITS
Author and Producer: Peter Cochran
Photography: Freestyle Productions
Zebra Media Productions
Narrators: Richard Cassell
Randye Kaye
Consultants: Ken Soltesz
Michael Worosz
Stock Video: ABCNEWS VideoSource
Rich Kearn
Leonard Rue Productions
National Park Service
Oxford Scientific Films
Post Production: North Country Media
Audio Sweetening: Acme Recording Studios
Produced for Rainbow Educational Media by
Cochran Communications
TABLE OF CONTENTS
Introduction .......................................................... 4
Program Summary................................................ 5
Objectives............................................................. 8
Review Questions................................................. 8
Activities ............................................................ 11
Glossary ............................................................. 13
Bibliography....................................................... 16
Related Videos from Rainbow ............................ 17
Appendix: Organizations to Contact................... 18
Script.................................................................. 20
INTRODUCTION
When students think of wetlands, they often picture
swampy, forbidding places full of mud and murky
water. However, wetlands are often places of great
beauty and contain an enormous variety of plant and
animal life.
Wetland Biomes: Essential and Endangered examines the major types of wetlands: freshwater swamps,
coastal mangrove swamps, freshwater marshes, salt
marshes, and bogs. It describes many of the animals
and plants that live in these different wetlands and how
they have adapted to the conditions that exist in each.
It explains how wetlands have benefited people by
providing food, controlling flooding, filtering pollution, and providing opportunities for recreation. Finally, the program examines the threats to wetlands
from developments and pollution.
The video is part of a series of Rainbow programs on
biomes.
Grade level: The video is appropriate for classes from
the fourth through eighth grades.
SUMMARY
The program opens with a group of students entering
a swamp. This section establishes the general characteristics of wetlands while emphasizing their diversity. The video describes how wetlands cover only
about 6% of the earth's land area, but play a large role
in our planet's animal and plant life.
The program introduces the different types of wetlands that will be explored in more detail in the
separate segments of the program that follow.
Swamps: This segment explains that a swamp is an
area whose vegetation is dominated by woody plants
like trees. Many of the plants in a swamp must be able
to withstand having their roots submerged for long
periods of time.
Focusing on the Fakahatchee Strand, a cypress swamp
in Florida, the video describes the various strata of
vegetation found in swamps and the types of animal
life that are common. It shows a group of students
collecting samples of fish from the swamp water.
This segment also describes a coastal mangrove swamp
that is a sanctuary for many types of birds.
Freshwater Marshes: In this section the program notes
that marshes are characterized by the absence of trees
or shrubs. Marsh plants tend to be soft-stemmed. The
video describes some of the plant life of a typical
freshwater marsh. Emergents grow with their stems
and leaves partly submerged. Submergents grow entirely under water. Floating aquatics include water
lilies that are rooted to the bottom and free-floaters
like duckweed.
Animal life described include amphibians, beavers
and birds. The program notes the importance of marshes
as breeding places for birds.
The video emphasizes how animals and plants are
adapted to their environment. For example, many
marsh birds have long legs for wading and long bills
for nabbing fish.
Salt Marshes: Tidal or salt marshes are restricted to
temperate coastal areas. They occur from the intertidal
zone to slightly above high tide.
The video shows the special kind of vegetation that
has adapted to survive conditions that exist in this
transition zone between salt water and dry land. Examples of plant life include spartina, phragmites, and
marsh elder. Examples of animal life include snails,
mussels, and fiddler crabs. This segment of the program ends by showing horseshoe crabs breeding.
Bogs: The video describes how many bogs started out
as lakes formed from rainwater or melted snow. These
lakes had no places for the water to run out. As a result
the water became stagnant. The stagnant, oxygenpoor and often acidic water of bogs doesn't support
decomposers like bacteria.
The video describes how undecayed plant material,
particularly from sphagnum moss, forms peat. It explains that because bogs don't provide as many nutrients for plant growth, you often find carnivorous
plants such as pitcher plants that trap and absorb
insects.
People and Wetlands: This section describes why
wetlands are important to people. Foods such as rice
are grown in wetlands. Many kinds of fish and shell
fish depend on nutrients from wetlands. Wetlands
help prevent flooding because they store water and
release it slowly. Wetlands filter pollution and help
clean water. Some communities use wetlands to purify their drinking water.
This section also describes various human impacts on
wetlands. Pollution has overwhelmed some wetlands
and threatens others. Wetlands have been lost to
agricultural and commercial development. The program describes the effects of canals, encroaching
farms and urban development, and the draining of
water on the Everglades in Florida.
A brief summary concludes the program.
OBJECTIVES
After viewing the program students will be able to:
1. define the characteristics of wetlands.
2. describe the three basic types of wetlands: swamps,
marshes, and bogs.
3. give examples of animal and plant life in wetlands.
4. describe how different plants and animals adapt to
wetland conditions.
5. describe how energy flows through wetland com
munities and the relationships of producers, consum
ers, and decomposers.
6. describe the human impact on wetlands.
REVIEW QUESTIONS
1. What is a biome?
A biome is an area that has a certain kind of
climate and certain kinds of living things.
2. What is a wetland?
A wetland is characterized by land that is wet.
3. What are the main types of wetlands? Describe
the major characteristics of each.
Freshwater marshes are characterized by softstemmed grasses and grasslike plants. Salt
marshes exist along coasts and are characterized
by plants like spartina that are tolerant of salt
water. A swamp is a wetland whose plant life is
dominated by woody plants like trees and shrubs.
A bog is characterized by stagnant water.
4. Why are wetlands homes to so many types of
animals?
Life depends on water, which is abundant in
wetlands.
5. How are birds adapted to life in a freshwater
marsh?
Answers may vary. Examples in the program
include the webbed feet of ducks and geese, the
long legs of wading birds, and the bills of birds
that feed on fish.
6. How is spartina adapted to the conditions of a salt
marsh?
It has glands that excrete the salt.
7. How have some bog plants adapted to conditions
where the water contains few nutrients and miner
als? Give examples of these plants.
There are several kinds of carnivorous plants
that get their nutrients and minerals by trapping
and digesting insects. Examples in the video are
sundews, pitcher and bladderworts.
8. How do wetlands help prevent flooding?
They can absorb great quantities of water that
would otherwise rush downstream.
9. How do wetlands reduce pollution?
They filter pollutants.
10. How are wetlands threatened?
They are being filled in for developments. They
are polluted from agriculture and other sources.
Water that normally would flow into wetlands is
often diverted for human use.
10
ACTIVITIES
1. Arrange for the class to visit a wetland. There are
many activities they can do. For example, students
can photograph the wetland at different times,
showing seasonal changes. They can also make an
inventory of the plants and animals they see. The
inventory can be repeated yearly by different classes
and the ongoing recorded data compared for
changes. Using cassette recorders, students can
record sounds of a wetland. They can then try to
match each sound with the animal that made it.
To find out what wetlands are close to you, contact
The National Geological Survey for a National
Wetlands Inventory map of your area. Call (800)
USA-MAPS.
2. Have students research and report on a wetland
animal and how it is adapted to its environment.
3. Ask students to form small groups and have each
group draw a wetland food chain showing how
energy flows from the sun to plants and from plants
to animals. Then have the class consolidate their
information to construct a food web.
11
4. Your class can help monitor and prevent pollution
of local wetlands. For information, contact:
Global Rivers Environmental Network
721 East Huron
Ann Arbor, MI 48104
(313)761-8142
e mail [email protected]
5. Ask students to compare a wetland's climate, land
scapes, and plant and animal life to those of another
biome, such as a rain forest, grassland, desert,
deciduous forest, or tundra. Ask them how the
conditions of each biome affect the kinds of life that
live there.
12
GLOSSARY
anhinga: type of wading bird that spears fish with its
bill
biome: area that has a certain kind of climate and
certain kinds of living things
bladderwort: carnivorous plant found in many bogs
bog: form of wetland characterized by stagnant water
and extensive peat deposits
bromeliad: type of epiphyte
canopy: highest layer of a swamp or forest
clam worm: animal that decomposes dead plant material in salt marshes
cottonmouth: poisonous water snake
cypress: large deciduous tree common in southern
swamps
decomposition: breaking down of a substance
duckweed: any of a family of very small flowering
plants that float on the surface of fresh water
ecosystem: community of living things along with its
physical environment
13
emergents: plants that root in the mud underwater and
protrude above the surface
epiphyte: plant that grows on another plant but gets its
nourishment from the air rather than from that plant
floating aquatics: plants like water lilies that float on
the surface of water
heron: wading bird often found in marshes and swamps
horseshoe crab: marine animal that is distant relative
of spiders
ibis: wading bird with a long, curved bill
mangrove swamp: coastal wetland where mangrove
trees grow
marsh: form of wetland characterized by grasses and
sedges rather than trees
marsh elder: shrub commonly found along the edge
of salt marshes
mud snail: animal that decomposes dead plant material in salt marshes
peat: dense layer of partly decayed plant material
found in bogs
photosynthesis: process in which plants use the energy of sunlight to convert water and carbon dioxide
into glucose and oxygen
14
phragmites: thick-stemmed grass that lives in fresh
and brackish water
pitcher plant: type of carnivorous plant found in
many bogs
prop roots: mangrove roots
rose pogonia; orchid found in many bogs
salt marsh: coastal marsh that is flooded daily by
tides
snipe: long-billed shorebird usually found near freshwater marshes
spartina: grass that is adapted to the salty water of salt
marshes
sphagnum moss: type of moss common in bogs
submergents: plants such as certain forms of algae
that never reach the surface of the water
sundew: type of carnivorous plant often found in bogs
swamp: form of wetland dominated by trees and
woody shrubs
wetland: places where the water table is at or near the
surface of the land or where the land is covered by
shallow water
15
BIBLIOGRAPHY
Duffy, Trent. Our Vanishing Wetlands. New York:
Franklin Watts, 1994.
Langley, Andrew. Wetlands Nature Search. A Joshua
Morris book from The Reader's Digest Association;
1993.
Lavies, Bianca. Mangrove Nursery. New York: Dutton,
1994.
Niering, William A. The Audubon Society Nature
Guide to Wetlands. New York: Knopf, 1985.
Sayre, April Puley. Wetland. Twenty-First Century
Books; New York: 1996.
Staub, Frank. America's Wetlands. Minneapolis:
Caolhoda Books; 1995.
Stone , Lynn M. Wetlands. Vero Beach, Florida:
Rourke Enterprises; 1989.
16
RELATED VIDEOS FROM RAINBOW
Amphibians: Amazing Animals
Animal Profile Series
Beyond the Bars: Zoos and Zoo Animals
Cool Creatures: Reptiles
Desert Biomes: Essential and Endangered
Grassland Biomes: Essential and Endangered
Oceans: Our Last Frontier
Our Changing Earth
Reduce, Reuse, Recycle: Environmental Concerns
Source of Life: Water and the Environment
Struggling to Survive: Tropical Rain Forests
Threats to Biodiversity: Why We Should Care
Treasures of the Deep: Our Ocean Resources
17
APPENDIX
Organizations to Contact
Chesapeake Bay Foundation
162 Prince George Street
Annapolis, MD 21401-9983
(410)268-8816
Friends of the Earth 218
D Street, SE Washington,
DC 20003 (202)5434312
National Audubon Society
700 Broadway
New York, NY 10003
National Wildlife Federation
1412 Sixteenth St., NW
Washington, DC 20036
National Resources Defense Council
40 W. 20th St.
New York, NY 10011
The Nature Conservancy
1800 North Kent Street
Arlington, VA 22209
(703) 841-5300
18
Sierra Club
30 Polk Street
San Francisco, CA 94109
The United States Fish and Wildlife Service
Publications Unit
4040 North Fairfax Drive
Suite 130
Arlington, VA 22203
(703)358-1711
The Wilderness Society
900 17th St., NW
Washington, DC 20006
19
SCRIPT
Title Wetland Biomes: Essential and Endangered
Female Narrator:
What is a wetland? In some ways a wetland is easy to
define. Its name seems to define itself. A wetland is
wet land, a combination of land and water, a place
where feet sink into the muddy ground or disappear
below the murky surface.
Male Narrator:
Wetlands are a biome, an area that has a certain kind
of climate and certain kinds of living things. There are
several major kinds of biomes. For example, grasslands are noted for their different kinds of grasses and
fairly dry climate. Tropical rain forests have a wet
climate and extremely lush vegetation. Deserts have
little rain at all and relatively little vegetation.
Female Narrator:
In some ways wetlands are harder to define than other
biomes because they take so many forms.
Swamps are wetlands. Some are forests of tall trees
whose bases rise out of a flooded forest floor.
Salt marshes are wetlands. They exist at the boundary
of sea and land, where plants and animals have adjusted to the daily rhythm of rising and falling tides.
20
Freshwater marshes are wetlands. Many border rivers,
lakes, and ponds. They have soft stemmed grasses and
other plants that can survive partly in and partly out of
the water.
Bogs are wetlands. They are covered by moss that
grows on top of layers of dead plant material called
peat.
Male Narrator:
Some wetlands are huge and stretch to the horizon in
all directions. Others can be measured in a few short
steps.
Wetlands exist throughout the world. There are wetlands in Canada and Alaska near the Arctic Circle, and
there are wetlands in tropical rain forests along the
equator.
Wetlands cover only about 6 percent of the earth's
land, but their importance is much greater than their
size indicates. Wetlands are thriving communities of
plants and animals. They are among the best places to
observe the different stages of life.
Let us look at different kinds of wetlands.
Subtitle: Swamps
Female Narrator:
A swamp is a wetland whose plant life is dominated by
woody plants like trees and shrubs. Only plants that
21
can withstand having their roots submerged for long
periods of time—like these cypress trees— can survive in a swamp. Many of the swamps in Florida and
other southern states are cypress swamps.
Swamps in other areas have different vegetation.
Northern swamps, like the Great Swamp of New
Jersey, have plants like red maples, black gum, and
ash.
Male Narrator:
In southwest Florida, students from the Everglades
City Middle School explore the Fakahatchee Strand, a
cypress swamp.
Swamps have distinct layers, each with its own kind of
life. Many unusual animals exist in the swamp water.
Glass shrimp are so transparent that you can watch
their stomachs digest their food.
Using small nets, the students easily capture several
species of small fish. Under the supervision of naturalist Mike Owens, they put the fish into aquariums.
After they've had a chance to study the fish, the
students release them back into the swamp.
Birds such as this great blue heron feed on fish and
other animals that inhabit the swampy waters.
A cottonmouth slides into the water in search of frogs
and other prey. The cottonmouth is highly poisonous,
22
but won't attack humans unless threatened. The
flooded forest floor is also home to turtles and many
other animals.
Female Narrator:
Above the floor of a cypress swamp, epiphytes cling
to the trunks and branches of the trees. Epiphytes are
plants that grow on another plant but don't get their
nutrients from that plant. Instead, they get their nourishment directly from the air and rain.
Among the different types of epiphytes are many
kinds of bromeliads, which are related to pineapples,
and various kinds of orchids.
The highest layer of a swamp is the canopy layer, the
tops of the trees themselves. Many kinds of birds—
such as herons—nest in the canopy of a swamp.
Male Narrator:
The Fakahatchee Strand and most other swamps are
freshwater swamps. Only a short distance away from
the Fakahatchee, along the southwest coast of Florida
there are other kinds of swamps: mangrove swamps.
Mangroves grow where few other trees can—in salt
water. Mangrove trees have stilt-like roots, called
prop roots, that support the trees against rising and
falling ocean tides and waves. The roots also are home
to oysters and many other kinds of animals.
23
Mangrove trees form islands that provide a home to
birds that nest in their canopy. As the sun sets, the sky
fills with different birds returning to these mangrove
islands, including pelicans, ibises, and herons. The
mangrove islands provide a sanctuary where these
birds are safe from most predators as they settle in for
the night.
Subtitle: Freshwater Marshes
Female Narrator:
Marshes can form in any shallow depression where the
soil becomes saturated, or so full of water that it can't
hold any more. Any additional water collects on top of
this saturated soil.
Many marshes look like shallow ponds full of weedy
plants. They may, in fact, have started out as ponds,
later to become marshes as they filled with decaying
vegetation. Marshes also lie along the banks of rivers
and lakes.
Male Narrator:
Marshes are more open, less dark and shady than
swamps. While swamps have trees and shrubs, marshes
have grasslike plants such as reeds. Such plants are
called emergents. This means that they grow with their
stems and leaves partly submerged.
Other plants—called submergents—grow entirely underwater. There are also floating aquatics—plants
24
like water lilies that float on the surface. Water lilies
are anchored to the bottom by their roots and have long
flexible stems.
Some floating aquatics don't have stems. What looks
like green slime coating this alligator in a Florida
marsh is actually thousands of tiny duckweed plants.
Duckweed has roots that hang down and absorb minerals from the marsh water.
Female Narrator:
Marshes are full of animal life. Raccoons are common
visitors to many marshes. In some marshes, you can
find beaver dams and lodges made of twigs and
branches. The beavers are often busy building and
repairing these elaborate structures.
The animals that inhabit marshes have special adaptations that help them survive in these environments.
Ducks, for example, have webbed feet to help them
move through the water. Other birds, such as this ibis,
have long legs for wading and long bills for nabbing
fish. Anhingas have daggerlike bills for spearing fish.
Marshes are important habitats for many different
birds. More than half of the geese and ducks and other
kinds of waterfowl in North America nest in freshwater marshes. These marshes are nurseries where—for
many animals—life begins.
25
Subtitle: Salt Marshes
Male Narrator:
Tidal or salt marshes exist in an environment that
changes dramatically every day as the ocean's tides
come in and go out. Twice a day, at low tide, muddy
flats are exposed to the air, only to be covered hours
later by salt water.
The vegetation in a salt marsh has adapted to survive
conditions that exist in this transition zone between
salt water and dry land. Each day as the tide comes in,
the plants in a salt marsh may be covered by salty and
often cold water, while at low tide they are exposed to
the dry air which —depending on the season—may be
hot as well.
Much of the grass in a salt marsh is spartina or cord
grass. Salt is harmful to plants, but spartina has special
glands that excrete or get rid of the salt. If you run your
finger over the grass, you can see the salty residue.
Another type of grass, phragmites, is somewhat less
tolerant of salt than spartina. It is more likely to grow
farther from the water.
Shrubs like marsh elder can be found along a salt
marsh's shore where the tides only occasionally reach
them.
26
Female Narrator:
Salt marshes are more productive than almost any
other places on earth in terms of how much plant
matter they grow. A salt marsh, for example, grows
more than twice as much plant matter as a corn field
the same size. Salt marshes are so productive because
they are full of nutrients brought in both by the ocean
tides and by freshwater rivers and streams.
Salt marshes are excellent laboratories in which to
observe the flow of energy in life. The ultimate source
of almost all life's energy is the sun. Plants use the
energy of sunlight to produce their own food and
grow. This is called photosynthesis.
When spartina and other plants in a salt marsh die, they
break down, or decompose, releasing their nutrients
back into the environment where other living things
can use them. The mud in the flats exposed at low tide
is actually made of decomposed plant material. Microscopic bacteria play an important role in decomposing dead plants and animals, but other creatures,
like these mud snails and clam worms, also act as
decomposers by chewing and shredding dead plants
and animals into smaller pieces.
Male Narrator:
All this decayed plant and animal material make the
water in a salt marsh a rich stew for many kinds of
animals, like this ribbed mussel, which filters the
water for particles of food.
27
When the tide is low, fiddler crabs feed on decaying
pieces of grass . When the tide comes in, they burrow
into the mud.
Fiddler crabs, mussels fish and other small animals are
themselves food for larger creatures. Like other wetlands, salt marshes are havens for many kinds of birds.
Some animals that spend most of their lives farther out
in the ocean breed in salt marshes. The unusuallooking horseshoe crab is one example. Horseshoe
crabs are actually not crabs at all, but distant relatives
of spiders. At high tide in late spring, a female horseshoe crab lays her eggs, and the smaller male fertilizes
them with his sperm. As they mate, some pairs are
exposed on the mud flats when the tide recedes, and
they risk being attacked and eaten by birds. They
slowly crawl into the water, creating a small trench as
they bulldoze their way through the mud.
Salt marshes are among the richest environments on
earth for life. Here, we can see—perhaps more clearly
than anywhere else —the universal cycle of birth,
growth, death and decay.
Subtitle: Bogs
Female Narrator:
While salt marshes are the most biologically productive kind of wetland, supporting a wide variety of plant
and animal life, bogs are the least productive.
28
A bog may have started out as a lake or pond formed
from rainwater or melted snow, but the water that
collected had no place to go. This stagnant, or inactive,
water has little oxygen and very few nutrients and
minerals. One result is that the water doesn't support
decomposers like bacteria that are common in other
wetlands.
Instead of breaking down and releasing their nutrients,
dead plants in a bog form mats of undecayed plant
material called peat. In some bogs the peat may be very
thick. Sometimes it forms on the surface of water so
that walking on a bog is a little like walking on a water
bed. The easiest way to see a bog, in fact, is by walking
on the more stable surface of a boardwalk,
There are many interesting things to see. Often you
will find different kinds of orchids, like this rose
pogonia.
Mats of sphagnum moss grow on top of the peat.
Sphagnum moss contains a great deal of acid, and it
makes the water in a bog very acidic. When it dies, this
moss becomes the main component of the undecayed
peat so that over time the peat becomes thicker and
thicker.
Male Narrator:
While the water in a bog is low in nutrients and
minerals, some plants have adapted to these harsh
29
conditions in an unusual reversal of how things occur
in nature.
In other wetlands, many animals get the nourishment
they need by eating plants. In a bog, the tables are
sometimes turned. There are carnivorous —or meateating—plants that trap unwary insects and other
small animals to obtain some of the nutrients they
need.
Sundews are a common bog plant. If you look closely
at a sundew, you might see an ant caught by the sticky
substance secreted by the plant's tiny hairs.
Pitcher plants get their name from their leaves, which
form a deep, pitcherlike shape. Special markings and
smells attract insects to their lips. Once they land,
however, they slip down the plant's slippery surface
into the liquid at the pitcher's base. This liquid contains juices that digest the insects.
The pretty yellow bladderwort is another deadly plant
for small animals, but the action doesn't take place
near the colorful flowers. Below the water's surface,
the plant has tiny, balloonlike bladders. These suck in
and digest tiny animals like red water mites.
Female Narrator:
You won't find the same kind of variety of animal life
in a bog that other wetlands have. Dragon flies and
other insects are common. Birds like this snipe and
30
other animals will occasionally visit a bog to feed on
plants, but for most animals bogs are difficult places to
live in.
Yet a bog is a still fascinating place to explore because
of the unusual plant life that exists there.
Subtitle: People and Wetlands
Male Narrator:
Wetlands are important to people for many reasons.
For one thing, we depend upon them for food. Over
half the world's population eats rice, which is grown
in wetlands. Two thirds of the fish and shellfish
obtained off the Atlantic and Gulf coasts of the United
States rely on nutrients from salt marshes and mangrove swamps. Decomposed plants and animals in
these wetlands are the basis of food chains upon which
fish and shellfish—and ultimately humans—depend.
Female Narrator:
Wetlands provide other benefits. They help prevent
flooding. In 1993 many places along the Mississippi
River suffered the worst floods in over one hundred
years as the river overflowed its banks. Billions of
dollars worth of damage was done to towns, cities and
farms when the Mississippi broke through levees built
to keep the river in check.
Wetlands can absorb great quantities of water and help
prevent such disasters. After heavy rains or when
31
snow melts in the spring, wetlands along rivers provide a place for the excess water to go rather than
rushing all at once downstream.
Wetlands also help clean water. As water flows through
a wetland, its plants filter out pollution. Some communities, in fact, use wetlands to treat their sewage.
Male Narrator:
As we have seen throughout this program, another
reason wetlands are important is that they provide
habitats for many different kinds of wildlife. Wetlands
help protect the earth's biodiversity, the diversity of
all its different plants and animals. In fact, one third of
endangered and threatened species, like the bog turtle,
live in wetlands.
For people, wetlands offer unusual opportunities to
observe and appreciate different kinds of plant and
animal life. Canoeists, bird watchers, hikers, fishermen, and hunters all take advantage of wetlands.
In spite of such benefits, however, many people have
not up to now recognized the worth of wetlands.
Female Narrator:
In many cases, the consequences of this ignorance or
indifference have been serious. The Everglades in
Florida offers one example. The Everglades is the
largest freshwater wetland in the United States. It is a
32
biological treasure. Alligators, turtles, snakes, and
many kinds of unusual birds make their home here.
Parts of the Everglades are marshes and parts are
swamp. Some call the Everglades a river of grass,
because the water in the Everglades is actually a broad,
shallow river that flows slowly from Lake Okeechobee.
Male Narrator:
Starting around 1900, however, state and local governments started building canals, so water that normally would have flowed into the Everglades could be
diverted for other purposes. Some of it was used for
drinking water for a growing population in Miami and
other places nearby. Much of it was used for farms,
particularly for growing sugar cane. The result was
that too little water reached the Everglades and much
of the water that did was polluted from agriculture.
One consequence has been that the numbers of many
kinds of wading birds and other kinds of wildlife have
decreased.
Female Narrator:
The Everglades is only one of many examples of the
human impact on wetlands. Throughout the world,
wetlands have been drained and filled to make way for
housing and developments. California has destroyed
90% of its wetlands.
The draining of marshes worldwide has led to a big
decline in the numbers of ducks and other waterfowl
33
that use these marshes to nest and feed. Throughout
the world, the numbers of frogs and other amphibians
have also declined sharply. One reason why some
amphibians are now threatened or endangered is that
their wetland habitats have been destroyed.
Male Narrator:
Fortunately, people have begun to wake up to what we
stand to lose if we continue to fill in or pollute our
remaining wetlands. What has happened to the Everglades is a warning signal of the damage that can be
done, but the Everglades are also a symbol of hope.
In the last few years, federal and state governments
and local people have worked to save the Everglades
and undo some of the damage. Canals that were built
to divert water away from the Everglades are being
taken apart so that water will flow once again into this
wetland refuge.
Female Narrator:
People worldwide are trying to conserve the marshes
that migratory birds depend on for breeding. In many
places people have taken a renewed interest in wetlands. Some are studying the plants and wildlife.
Others are researching how wetlands can protect us
from floods, or clean polluted water.
Male Narrator:
But even if these other reasons didn't exist, wetlands
would be worth saving for the sense of adventure we
feel when exploring a swamp,
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or seeing up close the carnivorous plants of a bog,
or observing an alligator swimming slowly through
duck weed,
or for the feeling of peace that conies from watching
the sun set on a marsh filled with birds.
End
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