Awards Earned: 1st Place, 7th Life Science, PCA Science Fair 2nd Place, 7th Life Science, ACSI Science Fair

How does different pH level affect algae cell structure?

I think algae will be healthier in a neutral pH (7).

My variables are spyrogyra growing in water with:
pH of 8 (normal pond pH 7.6-8.2)
pH of 7 (neutral pH)
pH of 6 (normal rainwater pH)
pH of 5 (normal lakewater pH)
pH of 4
pH of 3

My control group is Spyrogyra growing in water of neutral pH (7).

6-500ml bowls
6 liters sterilized pond water
2 lamps with 40 watt bulbs
one thermometer
concave microscope slide
200x microscope
pH hydrion paper
eye dropper
sulfuric acid
powdered limestone
1 Spyrogyra culture

Add 1 liter pond water to each of the bowls, label each bowl. Place the Spyrogyra cultures in the 6 bowls. Keep lamp over each group of bowls and keep at 20 degrees Celsius. Observe daily. When algae look healthy take a sample from each of the bowls and observe under the microscope. Sterilize all equipment for handling Spyrogyra with bleach and let sit for 24 hours to make sure all bleach is evaporated after each observation. Take another sample and observe under microscope. Then measure pH of water with pH hydrion paper. Add sulfuric acid to the bowls one drop at a time until correct pH is achieved. Add limestone 14.8 ml at a time to bowl 1 to achieve pH 8.
Bowl 1 of Spyrogyra should be pH 8 (normal pond pH 7.6-8.2).
Bowl 2 of Spyrogyra should be pH 7 (neutral pH).
Bowl 3 of Spyrogyra should be pH 6 (normal rainwater pH ).
Bowl 4 of Spyrogyra should be pH 5 (normal lake water pH).
Bowl 5 of Spyrogyra should be pH 4.
Bowl 6 of Spyrogyra should be pH 3.
Take a sample of each bowl and observe under a microscope. After 24 hours take a sample from each bowl and observe under a microscope. Record changes in cell structure. Draw a diagram of the algae. After another 24 hours take a sample, observe under microscope, record cell changes, and draw. Compare the changes in cell structures from the last recording.

The algae was healthiest in basic pH 8 and did better than the algae in the neutral pH 7. All the acidic pH's were more deteriorated than the basic and neutral pH. In the acidic pH's the more acidic the pH got the more deteriorated the cell structure became.

In conclusion my hypothesis was incorrect. The algae was healthiest in basic pH 8 and did better than the algae in the neutral pH 7. Next time I should try a pH 9 to see if the higher the pH the healthier the algae. What affect did the limestone and sulfuric acid have on the algae? What would have happened if a different material was used to change the pH.

This experiment attempted to determine what pH algae lives in with the least amount of cell structure change. Pollution creates acid rain which changes the pH of our lakes and rivers. This different pH changes the cell structure of algae, and God wants us to be good stewards of his earth. Therefore we need to know the effects of technological advancements on the earth.

Genesis 1:28 says, “And God blessed them, and God said unto them, be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish in the sea, and over the fowl in of the air, and over every living thing that creepeth upon the earth.”

This means we are to take good care of God's earth. We should be constantly trying to reverse the effects of acid rain which is destroying our plant life. And also we must try to reduce the production of pollution.

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