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Author(s): |
Jennifer
Lamkin, Pricilla Ornelas, Muy Taing |
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Summary
of Activity
50-100 words
Pond Science teaches students
about freshwater ecology through visiting a pond and then creating
ponds in the classroom. The activities include visiting a pond, collecting
organisms, viewing them under a microscope, performing simple chemical
tests, and finally creating ponds in the classroom. Each activity
will allow the students to become familiar with ponds and water as
a habitat and as a working ecosystem. The students will learn to utilize
the scientific method during the activities. Throughout the activities,
the students will keep a journal, including in it observations of
the pond environment, physical characteristics of the water, and drawings
of plants and animals in the pond. After examining the water and organisms
under the microscopes, students will compare what they saw, and use
it in a creative writing activity. Finally, by looking at the water
quality data and variety of organisms collected, the health of the
pond will be discussed and connected to the overall theme of water
pollution and conservation. The samples collected will be used to
reconstruct aquarium ponds in the classroom, and the class will be
able join the adopt-a-pond online project. |
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Grade
levels
This activity is appropriate
for 6th through 8th grade levels. The optimal class size for the activity
is 25 students, but it could be done with 20 to 30 students. |
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General
description or introduction
The scientific principles
that the activity is founded on.
Pond Science allows students
to develop their knowledge of the scientific method as well as freshwater
ecology. The activities presented will allow students to become scientists
and use observation skills, questioning, and data collection to come
to a conclusion about the ecology of a local pond. The creative writing
microscope activity allows students to connect science to other subjects
in a unique manner. Creating aquariums in the classrooms as small
groups allows them to use what they have learned throughout the project
to create a mini-ecosystem. The students must decide what organisms
will go into the pond, and how many of each organism should be added.
These ponds can then be monitored to "ecosystem design" is most successful.
The most successful pond is the pond that is self-sustaining for the
longest amount of time. However, success could also be measured by
the number of organisms in the pond after a certain number of days.
Pond Science is a fun, hands on learning experience that brings nature
into the classroom. |
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Background
information
Earth is the only planet known to have running water. In fact,
over 70% of Earth is covered by water. All of this water is filled
with life. Water is the habitat for a diverse range of flora and
fauna, as well as many complex ecosystems. These ecosystems can
be found in all types of water including lakes, rivers, streams,
ponds, oceans and seas.
Ponds: Ponds are great for studying fresh water ecology
since they are located everywhere and are usually small enough to
be able to monitor easily. Ponds, like other isolated fresh water
communities are composed of stagnant water. Though the water is
considered fresh, it has a low ion content, the majority of which
is salt. The water also tends to have suspended particles, which
can give the water a murky appearance. Ponds tend to be small, shallow
bodies of water with sunlight penetrating all parts. The pond environment
is suitable to many different organisms. Pond life includes unicellular
organisms, developing insects, plants and algae, fish (eggs and
larval stages), snails, amphibians ( larval and development stages),
worms, and many other organisms.
Each pond creates its own ecosystem, and in interesting to study
due to the diversity of the organisms inhabiting the water. Creating
ponds in the classrooms allows students to use what they learn during
the field trip and subsequent activities to solve the problem of
creating their own ecosystem. This activity makes the students into
scientists. To create a successful mini-pond, there must be the
correct combination of organisms, amount of food, chemical balance,
sunlight, and temperature.A pond creating activity is outlined below,
and there are also many books available providing useful information
on maintaining an aquarium.
Pollution: By studying ecological relationships, scientists
have been able to show exactly how pollution affects wildlife. For
instance, high levels of mercury and other poisons in bodies of
water are harmful to inhabitants. Ecologists have discovered that
warm-blooded animals use up to 90% of their food for staying alive
and moving about. Only about 10% is used for fueling the animal’s
growth. For example, if an animal containing a milligram of mercury
is consumed by a larger animal, it retains most of the mercury itself
because it cannot easily get rid of it. However, the amount of weight
the larger animal gains is only one-tenth of the smaller animal’s
weight. So the mercury becomes much more concentrated as you move
up the food chain. This process is called bioaccumulation or biological
magnification.
A pH reading is a simple test that can indicate the quality of
the pond water. Typically, ponds have a pH of 6.5 to 9.0. pH levels
can change due to the acidity of rain and run off entering the pond.
Acid rain is typically considered to be rain with a pH of 5.0 or
less. The effect of acid rain can range from unnoticeable to almost
total destruction. Some acidity of rain water is caused naturally
by volcanic eruptions and lightning strikes. Dissolved CO2 in rainwater
can cause a pH of 5.6. However, the type of acid rain that makes
news is caused by humans.
A lake or pond affected by acid rain may have a pH of 4.5 to 6.0.
A pond can usually maintain a pH flux between 6.5 and 7.5 with little
stress to plants and animals. If the pH falls to 6.0 or below, a
noticeable reduction in abundance of snails, amphibians, crustaceans,
zooplankton, and fish occurs. Many insects and rotifers will be
unaffected, while some amphibians, especially eggs, will be severely
affected by even a small pH change. A pH of 5.0 will kill most organisms.
Furthermore, when the pH of a pond becomes low, the effects of metals,
storms, and toxins, may become more pronounced, making their devastating
effects even more so.
The Scientific Method: The scientific method is used by
scientists conducting research and experiments. Part of the pond
science lesson is to allow the students to familiarize themselves
with the scientific method. For the purpose of this lesson, the
scientific method has been broken down into five simple parts. The
parts are observation, question, experiment, data/results, and conclusion.
Students make observations of whatever is being researched, in this
case the pond. They use these observations to formulate questions.
What each student thinks the answer to the question is becomes his
or her hypothesis. An experiment is then set up to test the hypothesis
and determine if it was correct or incorrect. The data and results
collected are the evidence that answer the question being researched.
Finally, a conclusion is made about the questions being asked. The
conclusion usually includes whether or not the hypothesis was correct,
and what the outcome of the experiment actually was.
Keeping a journal is important to this process, since the student
will be able to refer back to what he or she has done and try and
determine what was right, what was wrong, and exactly where any
error in the results came from.
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Credit
for the activity
.
This lesson plan was originally
done by Betty Moore, Fall Semester 1999. Information for the lesson
plan was taken from http://www.yale.edu/ynhti/curriculum/units/1992/5/92.05.07.x.html.
Additional ideas were taken from http://www.csis.pace.edu/schools/mv/bjackson/ourclasspond.htm,
which contains information about pond science and allows classrooms
to adopt a neighborhood pond and put it on-line, so that it can be
compared to other ponds around the country and the world. This site
also contains a simulated pond, which could be useful to test pond
ideas before setting up the ponds in the classroom. Dr Mangin provided
the information for collecting pond species around Tucson, and also
suggested the earth ball activity. References used in creating this
project include: Horne A. and Goldman C. Limnology 2nd Edition. McGraw-Hill
Inc. 1994. Taylor C. and Pople S. The Oxford ChildrenÕs Book of Science.
Oxford U.P. New York, 1995. |
Estimated
time to do the activity
Field Trip: 3 hours plus
transportation
Microscope Activity: 60-90 minutes pH tests 30 minutes
Set up of ponds: 60-90 minutes Discussion: 60 minutes On-line pond
(optional): 30 minutes |
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Goals
of Activity:
Goal
A
Utilize the scientific method
through activities. |
Goal
B
Improve use of both dissecting
and compound microscopes. |
Goal
C
Set up aquariums in classroom
in small groups. |
Goal
D
Discover what types of life are
found in ponds and discuss the pond ecosystem. |
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National
Science Education Standards. (NSES)
Two
content standards that this lesson plan covers:
Standard
1
Diversity and Adaptations
of Organisms Pond Science meets this standard with the collection
of organisms at the pond site and the microscope activity. While at
the pond site, students are asked to collect ten different organisms.
Collecting these organisms will give them an idea of the diversity
of the pond. Using the microscopes will allow the students to view
organisms that they cannot see with their eyes. The microscope activity
will help the students see just how far diversity extends within pond
life. The microscope activity will also allow the students to see
adaptations of organisms. The students are asked to draw the organisms
they see, and not special adaptations. The students are also asked
to predict how the organism functions as an individual and also in
the ecosystem based on these adaptations. |
Standard
2
Develop descriptions, explanations,
predictions, and models using evidence In Pond Science, the students
keep journals to write down descriptions of organisms and the environment.
They gather evidence to predict whether or not the pond is healthy.
The students also use their findings in a discussion after the experiment
to explain what was found. All of this information is then used by
the students to create a in classroom mini-pond. In creating the pond,
students use the information collected to predict what makes a pond
successful, and then they built a model to test their hypotheses.
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Materials
Needed
Aquariums or large bowls gravel
large rocks and screen (for covers if desired) Various habitat material
of your choice (live plants, wood, etc.) Collected samples from local
pond (or store) Microscopes (slides) Magnifying glasses (hand lenses)
small vials for collection containers for water containers for larger
animals and plants litmus paper lemon juice distilled water ammonia
thermometer journals pencils blow up earth ball, or the earth part
of a globe |
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Preparation
Engage: Initiate discussion about fresh water ecology by
completing this pollution activity as a class. This activity is
to show the effects of pollution in a body of water and wildlife.
The materials required are one gallon glass jar, a measuring cup
(250ml), and red food coloring. The first step is to pour a half
cup of water in the gallon jar. The second step is to add two drops
of red food coloring. The third step is to add one cup of water
at a time to the jar until the red color disappears. It should take
seven cups total to make the water clear. The red color is visible
at the start of the experiment because the molecules of red food
coloring are close enough together to be seen. As more water is
added to the jar, the molecules of the red food coloring become
further apart and invisible. Materials that are visible initially
at one spot in a pond or a steam will eventually become invisible
as it mixes with more water. This doesnÕt mean that the material
is gone from the water. Animals can drink the water and they can
be affected. This activity will allow students to start thinking
about the overall theme of conservation and other ecological issues.
Preparation: Obtain materials needed for collection of organisms
and water at the pond site. Obtain materials needed to create the
classroom ponds. Though some will be collected at the pond, it may
be necessary to purchase gravel, small fish, etc. from a local pet
store. Make copies of the treasure hunt worksheet. Collecting animals
and algae for the aquaria from local sources: Schedule a field trip
to a local pond, stream, small pool, swamp, or lake. For the Tucson
area, You can collect in streams in any number of canyons in the
Catalina mountains. For example, Sabino and Bear Canyons, Pima Canyon,
and Fingerrock are all good sites. Go in the spring after it has
warmed up and insects are flying so that you can find aquatic insects
and other insect larvae in the streams and stagnant pools associated
with the streams. For example, very fun insects for tank are the
yellow spotted predaceous diving beetles and whirligig beetles.
Both of these eat fish food. In the canyon streams, near Tubac,
or at Empire Ranch Cienega, you can find giant water scorpions -
these are very active and interesting in aquaria, however, you must
provide them with fish or live insects (e.g., flies) for them to
eat. Another good source of aquatic insects is cattle tanks. If
you are very lucky, you might find a giant water scavenger beetle;
cattle tanks or other stagnant, algae-filled ponds are a good spot
to find these. They are the size of very large cockroaches, but
with better personalities. They eat algae (or lettuce) and will
actively graze while you watch them in your aquaria. Sewage ponds
do not tend to have many insects or larvae; neither does aqua caliente
spring in NE Tucson. Anywhere there are lots of fish, there will
not be many insects - the fish eat them!
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Step-by-Step
Procedure for the Activity
I. Earth ball Activity
1. As a fun starting activity, have the students sand in a circle
and throw a inflated earth ball to each other. As each student catches
the ball, have them look where their right index finger is pointing
on the earth. Is it on land or on water? Use the numbers to calculate
the percentage of water on the each. Divide the number of students
that are pointing to water by the total number of catches. This
will be the percentage of water. The percentage should be around
75%. This activity will help students realize how much of the earth
is water. This activity could also be extended, by having the students
that are pointing to water decide whether it is fresh or slat water,
and then calculating the percentages of each.
II. Start a scientific journal
1. Each student should have his or her own journal to write down
all observations, hypotheses, and data collected.
III. Collection of organisms and pond water
A. Field trip to pond
1. Divide students into small groups to collect plants and animals.
Make sure each group goes to a different location around the pond,
i.e. sunny, shady, etc. Each group should record in their journals,
the appearance of the site, a description of the environment around
the site (including trees, grass, shrubs, etc. and their distance
from the water), any pollution nearby or sources of pollution, the
clarity, the turgidity, the temperature, as well as the presence
of algae on the surface and at the bottom of the pond. 2. Each group
should find plants and/or animals to fill out their pond Treasure
Hunt sheet. A sample sheet is provided below. Animal or Plant (common
name) Location Observations 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Possible
species for collection include insects and larvae, tadpoles, algae,
plants, small fish, worms, leeches, etc. Collected specimens will
be put into vials (with water) for later observation and identification
in the classroom. 3. Between five and ten students will be given
gallon jugs to collect pond water for testing and to be used in
classroom aquariums.
IV. Observe water samples under dissecting and compound microscopes
1. Look at organisms under the dissecting microscope. Students should
from small groups (two to three) Students should draw what they
can see. Students should attempt to identify the organism generally
as eggs, plants, worms, other animals, etc. While looking at the
organism, they should answer questions in their journals. What role
does the organism play in the ecosystem? How does it function individually?
What adaptations does it have? How many are there? 2. Look at organisms
under the compound microscopes. The students should remain in small
groups. The students should draw a variety of unicellular organisms.
The students should attempt to identify the organisms using the
same general guidelines. The students should also try to answer
the questions above, as well as comment about the variety and abundance
of the organisms. Was it more or less than expected? 3. Have each
group show some of their drawings to the class. Students should
say what they found, their observations, and also what area of the
pond the organism was found in. 4. The teacher can describe what
was found and add more information while the students are presenting
their findings to the class. 5. Creative activity. Students can
do this activity individually. Each student should pick an organism
that he or she saw under the microscope that hasnÕt been observed
previously. First allow students time to list adjectives, verbs,
and adverbs that come to mind. In a poem or short paragraph, the
students should compare their organism to something. It should be
something that they know, so that a new object can be related to
an old one. This activity will encourage creativity and writing
skills.
V. Learn about pH and test the pH of the water collected.
1. Students will form small groups to learn about pH if they have
not already. Students will use litmus paper to test the pH of an
acid (i.e., lemon juice) as well as a base (i.e., ammonia). Each
group will then make a hypothesis about the pH of the pond water.
The pH of the pond water will be tested, along with the pH of distilled
water, so that the two samples can be compared. The hypothesis and
results will be recorded in the journal and will be used as a basis
for the discussion of the health of the pond, and how the pH affects
the living organisms. 2. Each group can be given a pH chart, to
compare the pH of the pond water to the pH of other liquids to give
them a better perception of pH. A pH chart is provided below. Strong
Acid 0 Stomach 1.0-3.0 Soft Drinks 2.0-4.0 Lemon Juice 2.2-2.4 Vinegar
2.4-3.4 Cider 2.9-3.3 CowÕs Milk 6.3-6.6 Drinking Water 6.5-8.0
Eggs 7.0-8.0 Washing Soda 11.0-12.0 Quick Lime 12.4 Strong Base
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VI. Discussion of the health of the pond ecosystem
1. Observations on the amount of pollution seen at the site, the
clarity, and the pH information will be important in the discussion.
Pollution indicators may include: trash at the site, trash in the
water, pH below 6.5, location of the pond; is it near a factory,
in a city?. Also, if organisms collected have been identified, the
presence or absence of some organisms will also be an indicator
of the health of the ecosystem. For example an abundance of algae
nay indicate high levels of nitrogen, small or undersized organisms
may mean water is not healthy, some insect larvae typically develop
in more polluted water: if they are present, what conclusions can
be made?.
VII. Creation of the classroom ponds.
1. Students form small groups, size depending on the number of aquariums
or large bowls. 2. Each group will search for organisms and water
samples at different designated areas of the pond. The type and
quantity of organism added should be recorded in the journals. 3.
Fill the base of the tank with aquarium gravel that has been rinsed
well to discourage algae growth (mud samples can also be added to
the bottom of the aquarium.) 4. Use rocks, pieces of dead wood,
to create an underwater landscape and surfaces for snails to feed
on, for example. 5. Add enough water to fill the tank to about half
its depth. Overfilling the tank may reduce the amount of oxygen
that is dissolved in the water. Water collected from the pond can
then be added to the tank (this will allow the introduction of tiny
animals such as daphnia. Add rooted plants in pots. The plants should
be covered, but the water does not need to be too deep (1/2 to 3/4
full). Essential oxygenating plants, such as floating pond weed,
can be left to float freely 6. Finally, insects, fish, bugs, and
whatever other organisms have been chosen can be added. If the ponds
need to be covered, a screen can be placed on as a lid, and secured
with rocks. 7. Place the tanks in bright light, but not direct sunlight.
The plants in the tank will grow and provide the food needed by
the organisms. 8. Students should continue to observe the ponds,
and record observations in their journals. During their observations
they should look for changes occurring. Have any organisms disappeared?
Have any new organisms appeared.? Has the abundance of specific
organisms changed? The groups can compare their ponds to see the
success of different models.
VIII. Join On-line pond project
1. Visit the internet site www.csis.pace.edu/schools/mv/bjackson/ourclasspond.htm.
Follow the directions provided to enter information about the pond
studied. There is also information about other ponds that have been
adopted by classes around the world.
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Images,
work sheets, additional web pages
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Items
for discussion or conclusion
1st
question
How does the pond ecosystem
function and how does it compare to other ecosystems? |
2nd
question
Was the diversity of the pond
greater then expected? |
3rd
question
Why is important to monitor
pollution in ponds and other bodies of water? |
4th
question
What is the purpose of keeping
a journal, and what did you learn from it? |
Conclusion
The best concluding activity
for Pond Science is the set-up of the classroom ponds. In setting
the ponds up, the students must use the knowledge they have gained
throughout the procedures. Setting up the ponds in small groups is
a great way for the students to compare what they think will be successful.
Thus, they can learn from each other. The ponds will be able to be
monitored over time, so the students will be able to see the results
of their predictions. By reviewing and perhaps grading their scientific
journals, you can see if the students have utilized all the parts
of the scientific method throughout the procedure. Also, the drawings
in the journal will help to show whether the students have been successful
with the microscopes. Is the drawing an actual organism or is it a
blob on the lens? Another concluding activity is simply the discussion
of what the students found. Students should be able to discuss what
types of organisms were present and how they function in the ecosystem.
This discussion can be extended to many other ecosystems. Students
could hypothesize about the components that make other ecosystems
function. A great starting place would be to discuss the environment
in which the students live. |
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Beyond
the Activity
Further
activities which relate to and extend the complexity of the experiment.
Have students present
the outcome of their group ponds to the rest of the class. Have them
identify what was right and what was wrong and suggest possible solutions
to the problems. Have students design other experiments or research
projects that could be done in small groups and presented to the class.
Possibilities include: What does pond water look like under a microscope?
How does temperature, light, food, oxygen, and/or pollution effect
a pond? How to insects develop from eggs to adults? How do amphibians
develop from eggs to adult? |
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Web
Resources
A web address with information on the topic of the activity.
Web
Address
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Additional
References
Reference
Taylor C. and Pople S. The
Oxford ChildrenÕs Book of Science. Oxford U.P. New York, 1995. |
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