Introduction of Aquatic ecosystem

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An ecosystem is a natural unit of living and nonliving parts that interact to produce a stable system. Ecology is the study of ecosystems, or how living things relate to the environment and to one another. Understanding this relationship is important because living things and non-living things depend upon and impact each other.
Lesson 1: Aquatic Ecosystems
Keywords: ecosystem, ecology, watershed, surface water, hydrologic cycle,
evaporation, transpiration, precipitation, surface runoff, percolation, porous,
aquifer, groundwater, spring, pond, phytoplankton, zooplankton, photosynthesis,
An ecosystem is a natural unit of biological components. The plants
living and nonliving parts that interact within an ecosystem convert the
to produce a stable system. Ecology sun's energy into food, and are in
is the study of ecosystems, or how turn grazed upon by animals, which
living things relate to the are consumed by predators.
environment and to one another. Microorganisms within an
Understanding this relationship is ecosystem, such as fungi and
important because living things and bacteria, also exchange energy
non-living things depend upon and within the ecosystem by breaking
impact each other. down waste material to substances
that can be used by plants for food.
Ecosystems operate from day to day In this way, each element within the
by exchanging energy. The energy ecosystem depends on the others for
exchanged within an ecosystem is survival.
recycled between the physical and
Aquatic Ecosystems and Watersheds
Aquatic ecosystems include oceans, which water flows to reach a
lakes, rivers, streams, estuaries, and common body of water such as a
wetlands. Within these aquatic lake or pond. We all live in a
ecosystems are living things that watershed, or drainage basin.
depend on the water for survival, Watersheds can be as large as the
such as fish, plants, and Mississippi River drainage basin or
microorganisms. These ecosystems as small as a farm with a pond. Your
are very fragile and can be easily watershed may be made up of
disturbed by pollution. mountains, farms, houses,
businesses, or towns. You share
All living things within an ecosystem your watershed with all other living
share the same watershed. A things within the ecosystem.
watershed is an area of land over
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A watershed is a good example of directly into the water. This will have
how the living and nonliving things an effect on the organisms that
within an ecosystem depend upon depend on the water for survival. For
each other. Altering a watershed will example, some fish feed on
affect all the living things within that organisms in the water. Polluted
watershed. People can alter a water may cause these organisms to
watershed by paving over land and die, leaving the fish with no food.
constructing buildings. This will affect This is why we must understand
how water flows over the land and these relationships and protect our
may cause harmful materials to flow water resources.
Today’s Water
Only 1 percent of the water on Earth glaciers, within the ground as fresh
is available to humans as fresh groundwater, fresh surface water,
water. Most of the earth’s water and in the atmosphere. Fresh
exists in the oceans as salt water. surface water includes water in
The small percentage of water lakes, rivers, streams, creeks,
remaining on the earth’s surface is ponds, and
found trapped in polar ice caps and
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wetlands. Humans obtain their fresh This is why we must protect our
water from surface waters and fresh water supplies.
groundwater. These make up only a
small quantity of the world’s water.
The Hydrologic Cycle
The hydrologic cycle is the the surface as ground water. The
circulation of water among the water may exist as each of the three
oceans, the atmosphere, and the states of matter: solid, liquid, or gas.
land masses, through evaporation, Evaporation is the change in water
precipitation, surface runoff, and from a liquid to a gas. Water
groundwater percolation. The cycle evaporates from the surface of the
has no beginning and no end. This oceans, lakes, streams, and rivers.
means there is no new water put into As the sun heats the surface waters,
the cycle, the same water is used water will be released into the
over and over again. Water exists in atmosphere in the form of water
all stages of the cycle: oceans, vapor. The greater the sun’s energy,
clouds, lakes and rivers, and below the more evaporation occurs. The
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sun can also cause water to Plants and animals will use some of
evaporate from plants leaves the precipitation that falls over land,
through a process called and some of the precipitation will be
transpiration. absorbed by the ground and moves
Water vapor rises from the surface downward through the soil in a
waters and enters the atmosphere process called percolation. Once
where it is transported by winds. the surface water has moved
When atmospheric conditions are underground it is called
suitable, water droplets will form and groundwater.
stick together to form clouds. This
process is called condensation. The water that enters these
When the atmosphere is saturated, pathways eventually finds its way
or cannot hold anymore water vapor, back to the oceans through river
these droplets will be released and runoff, groundwater flow, and melting
fall to the earth’s surface as ice, which all discharge water into
precipitation. the oceans. This closes the
hydrologic cycle by returning the
Precipitation is water that is water originally removed from the
released from the atmosphere as ocean by evaporation.
rain, snow, hail, etc. Precipitation
that falls to the Earth’s surface can In this way, water goes around the
enter several different pathways hydrologic cycle. No new water is put
within the hydrologic cycle. on Earth; it is just stored in different
Precipitation that falls over bodies of places on Earth in different states
water such as lakes and rivers (solid, liquid, and gas). This means
becomes surface water, that we have the same amount of
Precipitation that drains across the water on earth today as when the
land and into lakes, streams, and dinosaurs roamed the planet.
rivers is termed surface runoff,
How Does Water Get Underground?
Water that falls to the earth’s surface underground through the tiny spaces
will runoff the land to join a body of between rocks.
water, be absorbed by the soil and
move downward through the ground Groundwater is important because
or be evaporated. Water that seeps most of the population depends on
into the soil will percolate through the underground water for drinking
ground and become part of the water. Groundwater can become
underground water system. This is polluted through percolation of
how surface water gets contaminated surface waters. The
underground. Groundwater moves water on the surface will pick up any
contaminates on the ground and
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transport these through the soil into the groundwater.
Underground Water and Aquifers
Below the ground is a series of rocks pollutants that may be found in the
that act as a sponge for water.
groundwater, soaking up water and Your local aquifer holds fresh
holding it in many crevices and groundwater beneath the surface. In
grooves. The spaces in a rock where some areas the aquifer will be deep
the water will move are called pores. within the ground and covered by a
A rock that has many pores is called thick layer of rock that is not as
a porous rock. An underground porous as the rock of the aquifer
water system that is made of very below. In other areas the aquifer is
porous rock and sand material is not far beneath the surface and
called an aquifer. An aquifer holds water can easily seep into the
and allows groundwater to flow ground and enter the aquifer. This
through the spaces between the type of aquifer also allows harmful
rocks. The rocks help filter the pollutants on the surface to easily
groundwater by absorbing some enter the aquifer and contaminate
the groundwater.
How Does Underground Water Get to the Surface?
Groundwater can also re-emerge at Springs can discharge freshwater
the surface. Underground water can into large surface water bodies such
sometimes flow into a surface water as lakes and streams, and even
body such as a lake, stream, or offshore in the oceans. Springs
pond. For example, a spring is connect the groundwater to the
water that is returning to the surface surface water.
after being absorbed by the ground.
Pond Cycles
Ponds play an important role in Ponds are important to the
aquatic ecosystems. Ponds can watershed connection. They capture
develop naturally in a low-lying area rainwater as it flows over the ground,
and produce a surrounding reducing erosion and flooding. By
ecosystem that is unique. Wildlife holding stormwater, ponds allow
depends upon ponds for food, nutrients and other chemicals to be
shelter, and breeding. Ponds can filtered from the water by plants and
provide much needed water for birds animals before it moves into rivers
an 8d wildlife. and lakes. Therefore, ponds can
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help protect the watershed from processes. The plants and animals
harmful pollutants. of a pond work together for survival.
Water is essential to the pond
Ponds are a good example of an ecosystem. The quality of the water
ecosystem in which all elements can determine the type of aquatic
work together to maintain a balance animals found and the health of the
between physical and biological ecosystem.
The Role of Aquatic Plants
Plant life that grows in and around a feed on fish. Birds and small
pond ranges from single celled mammals make up a higher level of
algae, called phytoplankton, to the food chain in a pond.
large woody trees. Plants are vital to
the functioning of ponds. Plants that Larger aquatic plants can grow
grow along the edge of a pond help rooted to the bottom of ponds and
reduce erosion, capture pollutants are supported by the water. These
before they can enter the water, plants help stabilize the sediments
stabilize sediments, and take up on the bottom of the pond. They also
excess nutrients. provide food and living space for
animals that live on the bottom, such
Plant life converts energy from the as snails. Rooted plants also help
sun into food through keep the pond water clear and free
photosynthesis. By converting the of algae because they take up
sun's energy and water's nutrients nutrients, which would otherwise be
into carbon-based energy, plants available to algae.
form the base of the food chain in
ponds. Tiny animals in the water, Plants can also affect the bird life
called zooplankton, use that is found near a pond. Birds use
phytoplankton as a food source. large aquatic plants for nesting,
Larger animals such as fish, use resting, and refuge. Large plants are
zooplankton as a food source. And also used for food.
still larger animals, such as birds,
The wildlife present in a pond can Aquatic animals help recycle the
range from amphibians to migrating nutrients within the pond ecosystem.
birds. Common wildlife species that By feeding on plants, seeds, fruits,
are found near ponds include: and tubers they take up nutrients
raccoons, birds, turtles, snakes, from the water and recycle them
frogs, and salamanders. when they decay. Animals can also
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remove nutrients from the pond by it and deposit the seed in a new
feeding on plants and moving out of area, creating a new habitat.
the pond, either to the surrounding
area or another ecosystem. Most of the wildlife spend the
majority of their lives in the areas
Animals of the pond are important surrounding the pond. Therefore, the
seed dispersers. Many animals will type of land present around the pond
disperse seeds around the pond is important. For example, female
ecosystem and thereby help turtles must dig holes in the
maintain the population and diversity surrounding banks and lay their
of plants. Animals can also disperse eggs. The pond edge is important
seeds to other areas. A migratory habitat for insects, frogs, small fish,
bird that injests a seed can transport and wading birds.
The Pond Watershed
Ponds are important to the overall is used for agricultural purposes then
health of the watershed because chemicals used on the land may
they collect stormwater before it contaminate the water of the pond,
enters larger water bodies. raising the nutrient levels. A pond
Stormwater draining from the nearby can become harmful to fish and
land can contain many unwanted wildlife when unnaturally high
chemicals that can be taken up by nutrient levels are present.
plants and animals and redistributed
within the ecosystem. Ponds often The best way to maintain a healthy
drain into larger bodies of water such pond ecosystem and surrounding
as lakes and streams. Therefore, it is watershed is to prevent water
important to maintain the health of pollution by picking up any debris
the pond. that could be washed into the pond,
using fertilizers sparingly on your
The type of land surrounding a pond lawn, and learning about the native
is important to maintaining the health aquatic life of your local pond.
of the pond. If the surrounding land
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Water Facts:
There are about one million miles of pipeline and aqueducts for water delivery
in the US and Canada...enough to go around the earth 40 times!
Water is the most common substance on earth, however only 1% of the
earth's water is available for drinking.
66% (two-thirds) of the human body is water. A cow must drink 3 gallons of
water to make 1 gallon of milk.
75% of a tree is water. 70% of an elephant is water.
You can survive about three weeks without food, but only 3 days without
It takes 50 glasses of water to grow enough oranges to make 1 glass of
orange juice.
You can fill an 8 oz. glass of water about 15, 000 times for the same cost as a
six pack of soda pop.
Rivers and streams make up 3.5 million miles.
Lakes cover 41 million acres
The average daily requirement for freshwater in the United States is about
338 billion gallons.
There are more than 200,000 individual water systems providing water to the
public in the United States.
If the Earth were completely flat, it would be covered by water 2 miles deep!
One gallon of gasoline can contaminate 750,000 gallons of water.
We use about 108 gallons of water per person per day in our homes.
There’s as much water in the world today as there was thousands of years
ago. In fact, it’s the same water.
A single dripping faucet can waste far more in a single day than one person
needs for drinking in an entire week.
Every glass of water brought to your table in a restaurant requires another
two glasses to wash and rinse the glass.
A leak of one drop per second wastes 2,400 gallons of water per year.
If you find any interesting facts, or have any questions that you would like to share with the staff
at Project Oceanography, please feel free to call us at: 1-800-51-OCEAN or e-mail us at: We will answer you either via e-mail or on the air during a broadcast.
Visit our website at
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Activity 1-1. Create Your Own Watershed
To teach the function of watersheds
To stimulate thought about the role watersheds play in the world
Materials needed
• Large aluminum cake pan
• Several pieces of crumpled paper
• Large sheet of aluminum foil or plastic wrap
• Variety of colored powders (cocoa, fruit drinks, etc.)
• Clear Water
• Spray Bottle
• Small model pieces to represent homes, trees, cars, farm animals, etc.
1. To set up the activity, crumple several pieces of newspaper or other paper.
2. Place paper in cake pan to represent different elevation levels of land. Cover
the paper with aluminum foil or plastic wrap. Position small model pieces as
3. Use a spray bottle to spray clear water at the highest elevation. Observe
4. Add small amounts of colored powders to various places to represent soil
erosion, green fruit drink mix powder may represent fertilizer, etc.
5. Again, use the spray bottle to spray water at the highest elevation. Observe
Discussion Questions
1. What happened the first time you sprayed clear water on your watershed
2. What happened to the pollutants when you sprayed water again?
3. What could be done to reduce the amount of pollutants affecting your
4. How does your watershed compare with watershed models made by other
5. classmates?
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Activity 1-2. Edible Groundwater Model
Source: The Groundwater Foundation Kids Corner.
To teach about the geologic formations in an aquifer
To demonstrate how pollutants enter the groundwater system
To illustrate the effects of pumping on the groundwater system
Materials needed:
• Blue or red food coloring
• Vanilla ice cream
• Clear soda
• Crushed ice
• Cake decoration sprinkles
• Drinking straws
• Clear plastic cups or bowls
1. Fill a clear plastic cup or bowl 1/3 full with crushed ice to represent gravel
and soil.
2. Add enough soda to just cover the ice.
3. Add a layer of ice cream to serve as a confining layer over the water-filled
4. Then add more crushed ice on top of the confining layer. Colored sprinkles
represent soils and should be sprinkled over the top to create the porous top
5. Now add food coloring to the soda. The food coloring represents
6. Watch what happens when it is poured on top of the‘aquifer’.
7. Using your straw, drill a well into the center of your aquifer.
8. Slowly begin to pump the well by sucking on the straw. Watch the decline of
the water level. Notice how the contaminants can get sucked into the well
area and end up in the groundwater by leaking through the confining layer.
9. Now recharge your aquifer by pouring more soda over the top. This
represents rain falling.
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Aquatic Ecosystems
Water is important to all living important to use our water
things. Not only do people need carefully and protect it from
water, but plants, animals and pollution.
other living things need it too.
Did you know that two-thirds of In order to know how to protect
your body is water? And almost our water, we must first
every living thing depends on understand where it comes
water for more than half of its from. As water travels through
body weight. the environment it changes. It
can become part of an ocean or
For example, a pond. It can be absorbed by
a living tree is 75% water, the soil for plants to use. It can
an elephant is 70% water, travel through your own
a tomato is 95% water, county’s water system and right
an ear of corn is 80% water. out the end of your faucet.
These paths that water takes
All living things are connected as it travels through the
through the need for clean, environment make up the water
fresh water. That is why it is so cycle.
Water traveling through
your neighborhood may fall
from clouds and run over
streets and lawns into a
nearby lake, stream, or
pond. The land that water
flows over before it reaches
a body of water is called a
watershed. Everyone lives
in a watershed. Your
watershed may be made up
of mountains, farms, houses, or businesses.
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