The Effect of Acid Rain on the Survival Rate of Daphnia

Researched by Megan M.
2003-04

PURPOSE

The purpose of this experiment was to determine the effect of acid rain on the survival rate of daphnia.  

I became interested in this idea after I went on a field trip to Portland, Oregon and learned a great deal about acid rain and how it destroys living things.  

The information gained from this experiment could help factory owners and managers become aware that pollution from their factories causes damage to the food chain for water animals. Also it could let wildlife biologists better understand the effect of acid rain on freshwater plankton like daphnia.

HYPOTHESIS

My hypothesis was as the concentration of acid in the water increases; the survival rate of the daphnia will decrease.

I based my hypothesis on a movie I watched on the Internet. The movie explained; when sulfur dioxides and nitrogen oxides mix with sunlight, oxygen, and water it creates acid rain. Then when the acid rain falls to earth, it may kill forests, lakes, animals and many more things depending on how much of the pollution mixes with sunlight, oxygen, and water.

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EXPERIMENT DESIGN

The constants in this study were:

  •  Species of daphnia
  •  Age of daphnia
  •  Housing method for daphnia
  •  Number of daphnia in each test group
  •  Test containers’ size and type (Petri dishes)
  •  Amount of acid/water mixture used for each test
  •  Temperature of the acid/water mixture
  •  Amount of time daphnia were observed following introduction of acid
  •  Observation method (jeweler’s loupe)
  •  Light, temperature, and humidity of test environment
  •  General testing procedure


The manipulated variable was concentration or pH of the acid/water mixture the daphnia were subjected to.

The responding variable was the percentage of daphnia surviving at 15-minute intervals following introduction of the acid/water mixture.

To measure the responding variable I used a jeweler’s loupe to observe the daphnia for a heartbeat and counted the number of living (surviving) daphnia in each group for 15 minutes.

MATERIALS

QUANTITY ITEM DESCRIPTION
120 Daphnia pulex
7 Petri dish
20ml  Water
5ml Sulfuric Acid
1  Jeweler’s Loupe
1  Eye Dropper
2 Sheets of Paper
1  Pencil (to record data)

PROCEDURES

1. Get Petri dishes ready.  
2. Use an eyedropper to get 10 Daphnia out of the jar.
3. Put 25ml of H20 into a Petri dish.
4. Set timer for 15mins.
5. After every 5mins check and see how many Daphnia have still survived.
6. When 15mins are over use the Jewelers loupe to count how many Daphnia survived.
7. Record your data.
8. Put the lid back on the Petri dish and label it control group.
9. Take another Petri dish and add 5ml sulfuric acid into it.
10. Use an eyedropper to get 10 Daphnia out of the jar.
11. Pour 20ml H20 (including the water you got from taking the Daphnia out of the jar) into the Petri   dish.
12. Repeat steps 4-7.
13. Put the lid back on and label it 5ml sulfuric acid 20ml H20.
14. Take another Petri dish and add 5ml of the group labeled; 5ml sulfuric acid 20ml H20.
15. Use the eyedropper to get 10 Daphnia out of the jar.
16. Add 20ml H20 (including the water you got from taking the Daphnia out of the jar) into the Petri dish.
17. Repeat steps 4-7.
18. Put the lid back on and label it 5ml (5ml sulfuric acid 20ml H20) 20ml H20.
19. Take another Petri dish and add 5ml of the group labeled; 5ml (5ml sulfuric acid 20ml H20) 20mlH20.
20. Use an eyedropper to get 10 Daphnia out of the jar.
21. Add 20ml H20 (including the water you got from taking the Daphnia out of the jar) into the Petri dish.
22. Repeat steps 4-7.
23. Put the lid back on and label it 5ml (5ml of 5ml sulfuric acid 20ml H20) 20ml H20.
24. Take another Petri dish and add 5ml of the group labeled; 5ml (5ml of 5ml sulfuric acid 20ml H20) 20ml H20.
25. Use an eyedropper to get 10 Daphnia out of the jar.
26. Add 20ml H20 (including the water you got from taking the Daphnia out of the jar) into the Petri dish.
27. Repeat steps 4-7.
28. Put the lid back on and label it 5ml (5ml of 5ml sulfuric acid 20ml H20) 20ml H20.
29. Clean and rinse things used thoroughly.  

RESULTS

The original purpose of this experiment was to determine the effect of acid rain on the survival rate of daphnia.  

The results of the experiment were the less acid you put on the Daphnia the more survived. Every time I took 5ml of the test I just did the less acidic it was. The strongest acid I used was 4. 5. 5 of the 11 Daphnia had died. The least acidic only I Daphnia had died.  

See the table and graph.

CONCLUSION

My hypothesis was that the concentration of acid in the water increases; the survival rate of the daphnia will decrease.

The results indicate that this hypothesis should be accepted. The more acid I used in the water the fewer Daphnia survived.  

Because of the results of my first experiment, I wondered if I had used a different test organism would there be different results.  

If I were to conduct this project again I would test the daphnia longer. Maybe for 24 hours instead of 15-30mins.


RESEARCH REPORT

Introduction

Acid Rain forms when sulfur dioxides and nitrogen oxides mix with sunlight, oxygen, and water. It can hurt or damage many things, such as daphnia. Daphnia are from the group called arthropods.

Arthropods

Adult arthropods have jointed bodies and external skeletons. This exoskeleton may be thick like crayfish or transparent like Daphnia. Arthropods are divided into many groups which are the crustaceans, centipedes, millipedes, insects, and spiders.

Daphnia

Daphnia are from the group called Arthropods. There are up to 150 known types of Daphnia. Generally they all swim, breath, and eat the same way.  

Daphnia swim with a jerky motion through the water. (That is how it got its nickname “water flea”. ) Then with a stroking action they move toward the surface. They pause for a while, before the next stroke to the bottom.

Daphnia breath from either collecting oxygen from the water or when they capture their food.  

They eat by using the five pairs of legs inside the body to capture microscopic food. They mostly eat algae, protozoa, and bacteria. After it captures its food it will fall to the bottom of the pond or shallow lake.  

There are many body parts in Daphnia. Such as the heart that pushes clear fluid around the body. The heart beats from 25-35 times per 10 seconds. The eye is controlled by muscles with nerve connections to the brain. The first and second antennas are used for swimming and sensing the environment. The legs are used for collecting food and balancing the animal as it slowly sinks. The gut is where food particles are digested. They also have a brood pouch for incubating young that hatch from large yolk filled eggs. They have a protective outer shell.  
 

Pollution

There are many different forms of Pollution. In many large cities automobiles, and factories pollute the air so much that it creates smog. The smog can endanger many people in that area. For an example, in Los Angeles and Mexico City smog is a constant problem. Another form of Pollution is greenhouse gases. This rises miles into the atmosphere, way above the smog.  
Waste is another form of Pollution. Plastic Industries pollute third world. Countries in 1989 U. S. corporations threw away more than 12 billion pounds of plastic. There are many more types of pollution in our world that are big problems. The big problems turn into many little problems. Then we just have too many. One problem America can prevent is acid rain.

Acid Rain

Acid Rain is a dangerous form of pollution. Acid rain occurs when sulfur dioxides and nitrogen oxides mix with sunlight, oxygen, and water. The sulfur dioxides and nitrogen oxides come from burning fossil fuels in power plants, factories, and motor vehicle engines. Acid Rain can damage a lot of things such as forests, lakes/ponds, buildings, animals, cars, and many more things. The things that risk damage are building materials such as steel, paint, plastics, cement, masonry, galvanized, limestone, sandstone, and marble. For these to be replaced costs billions of dollars.
The cleanup from all of the damage could take about a decade (10 years).
To reduce acid rain people should start carpooling. Then that would reduce some of the dioxides and oxides all over the world.
 

Summary

Acid Rain can hurt or damage many things. If acid rain kills the daphnia it will cause damage to the food chain for water animals. Also if it damages buildings it will not make that area a very good place to live.
 
BIBLIOGRAPHY

“Acid Rain: Scourge From the Sky. ”1995.   http://elibrary. bigchalk. com 

“Daphina. ” November 5,2003. http://ehiomedia. com 

Michael Allaby. Fog, Smog, and Poisoned Rain. New York: 2003 page 6.  

The Acid Rain Story. Canada:1984 pages 3,6 

“What Causes Acid Rain?”11/18/03  http://elibrary. bigchalk. com

“Why Daphnia?. ” November 5,2003.
http://ei. cornell. edu/toxicology/bioassays/daphina/

“What causes Acid Rain?” Enteractive, Inc. 1995.

van Egmond, Wim. “Water-flea anatomy. ” http://www. microscopy-uk. org. uk/mag/artmar02/fleanatomy.html 12/3/03
 

ACKNOWLEDGEMENTS

I would like to thank the following people for helping make my project possible:
  •  My parents for buying my science supplies.  
  •  My teachers for helping me, providing daphnia and diluting the sulfuric acid to safe levels.

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