Something Fishy Going On
Activity Time: 60 minutes
TEACHERS: Read “‘Populution and Water Source Protection” on page 80 of Peel Water Story book.
Objectives:
Students will:
• define the term “acidic”.
• define the term pH.
• describe what happens to aquatic life when pH levels change.
Introduction:
This activity aims to educate and empower students to become active guardians of their water
supply by increasing their awareness of how changing pH levels have adverse effects on an
ecosystem. In this activity, the students will test different household substances to determine how
they measure on the pH scale. They also will be able to compare a “normal”/healthy lake to one
that has been affected by acid rain.
Background Information:
• Acids & Acid Rain - Acids in water solutions turn litmus paper RED. They alter pH levels in
lakes, destroying certain populations of plants and animals and causing other populations to
explode, drastically altering the delicate balance of the ecosystem. Acid rain (the source of
the acidification of lakes) is caused by industrial pollutants and automobile emissions. These
pollutants combine with water in the atmosphere and fall as acid rain. Rainwater with a pH
of less than 5.3 is considered acidic.
• pH – (potential Hydorgen) a range of numbers from 0 to 14 with acidic solutions having a pH
below 7 and basic solutions having a pH above 7. A pH value of 7 exactly is considered a
neutral solution.
• Buffer - A buffer is a solution that can keep its pH constant, despite the addition of strong
acids or strong bases.
• The results for living organisms: Many acid-base reactions take place in living organisms.
However, for organisms to perform certain vital functions, the body fluids associated with
these functions must maintain a constant pH. For example, blood must maintain a pH of
close to 7.4 in order to carry oxygen from the lungs to cells; blood is therefore a powerful
buffer. If the pH in the environment changes too much (i.e. too acidic or too basic) the
organism’s buffering capacity is lost, and the organism will die because it will not be able to
perform many vital functions. This will affect the whole ecosystem and/or food chain.
• DO NOT TASTE THE LIQUIDS AND WASH HANDS AFTERWARDS
• Reference: http://www.epa.gov/acidrain/
Materials:
y pH test strips
y Milk
y pH scale colour guide
y Vinegar
y Lemon Juice
y Baking soda
y Bottle of Water
y Antacids (e.g. Rolaids or Tums)
y One large container with representations of animal life in a “normal” lake
y One large container with representations of animal life in an “acidified” lake
Procedure:
Peel Water Story, Environment, Transportation and Planning Services Department, Region of Peel
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1. Start by introducing the concept of pH and acids. Ask the students if they can think of
common things that might be acidic (e.g. vinegar).
2. Students will be testing the pH levels of various household substances. Give each student
a few paper pH strips (please note: can only be used ONCE). Explain to the students that
this is special paper, which determines how acidic or basic substances are.
3. Test the pH by having the students dip the paper into containers with the substances
provided. Students can then determine the pH level by matching the colour to the chart
provided. Next, test the pH of water (tap water, or bottled water). They will discover
that many common substances can be acidic and still be consumed by humans. Please
ensure students do not TASTE any of the substances provided.
4. Be sure to refresh the liquids that have changed colour due to the pH strips themselves.
5. Ask the students if fish or other aquatic life could live in substances such as lemon juice or
vinegar. Why of why not? Explain the concept of acid rain and what causes it (see
background information above). Encourage discussion around what could happen when the
ecosystem is disrupted. For example, what would happen if one species of small fish was
unable to adapt to the acid conditions and died off. What would happen to the larger
organisms that fed on that small fish and so on up the food chain?
6. Next, have the students reach into the “normal” lake container. This will be filled with
examples of healthy fish and plants (artificial). Then have the students reach into the
“acidified” lake container. Explain that this represents the same lake with the pH level
changed. This container will be virtually empty, with only a few items (like insects)
representative of a lower pH level.
Debrief:
Ask the students to tell you ways they can help prevent acid rain. Remind the students that
they can stop acid rain by doing things that stop air pollution too. All of the factors that
contribute to smog also cause acid rain. Students can do the following:
• Ride a bike or walk whenever possible to limit automobile use.
• Conserve energy to reduce power production needs.
• Use public transit as often as possible to limit automobile use.
• Be smart shoppers as they get older, buying locally grown products like fruits and
vegetables to limit the emissions from trucks and planes used to ship produce from
afar.
• Spread the word! Encourage others to help stop acid rain too!
Also, try the Peel Water Story activity: Water Hogs Make Smog.
Adapted from the Peel Children’s Water Festival by the Region of Peel’s Environment, Transportation
and Planning Services Department, Public Education & Outreach.
Contents of this publication may be photocopied provided the source is acknowledged on every page by
including the following Peel Water Story, Environment, Transportation and Planning Services
Department, Region of Peel
Not to be adapted or reprinted without written permission of the Environment, Transportation and
Planning Services Department of the Regional Municipality of Peel.
Address: 10 Peel Centre Drive, Brampton, Ontario L6T 4B9
Peel Water Story, Environment, Transportation and Planning Services Department, Region of Peel
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Peel Water Story, Environment, Transportation and Planning Services Department, Region of Peel
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