PURPOSE
The purpose of this
experiment was to determine the effect of motor oil on the survival rate of
brine shrimp.
I first became interested in this idea because I had heard horrible reports, over and over, from watching the news about the pollutants getting in our lakes, rivers, seas, and oceans that damage the aquatic life. I wanted to see for myself how a common pollutant would affect an organism. I chose to test on brine shrimp because they are at the bottom of the food chain. If the motor oil killed them then the whole food chain itself would collapse.
The information gained from this experiment could warn anyone who owns a car how much the motor oil that they dispose of could affect the population of living creatures in our waters. Oil must be disposed of correctly. Pollutants add up in the environment, so my results would help us in the future.
My first hypothesis was
that as the amount of motor oil in the water increased the survival rate of the
brine shrimp would decrease.
My second hypothesis was that the more motor oil there was in the water the shorter time the brine shrimp would survive.
The constants in this study
were:
- The amount of brine shrimp in each Petri dish (10)
- The amount of water in each Petri dish (5 ml.)
- The type of water in each Petri dish (salt water)
- The total time the brine shrimp were left in the Petri dishes (1 hour)
- The frequency of when the brine shrimp are checked during the test (every 10 min.)
The manipulated variable was the amount of motor oil put in each Petri dish.
The responding variable was the rate of the deaths of the tested brine shrimp.
To measure the responding variable, I counted how many brine shrimp survived in each petri dish about every 10 min. for a period of 1 hour.
MATERIALS
QUANTITY
|
ITEM
DESCRIPTION
|
4
|
droppers
|
1
|
brine shrimp hatcher
|
1
|
container of brine shrimp
eggs
|
20
|
Petri dishes
|
1
|
timer
|
1
|
bottle motor oil
|
1
|
L. water
|
55
|
g. salt
|
1
|
egg
|
1
|
disecting microscope
|
4
|
syringes
|
1. Prepare the salt water
a) mix
55 grams of non-iodized salt into each 1 liter of distilled water
2.
Culture brine shrimp at 20ο C.
a)add ¼ tsp. Of dry eggs to
½ a liter of salt solution
b)Let them grow for about 48 hours
3. Mixing together the salt water and motor oil
a)Mix
water and motor oil together using an emulsifier, then stir
b)I
used 5 ml. of egg white in each petri dish
c)Have
10%of motor oil with 5 ml. of salt water into one petri dish
d)Then double the amount of motor oil that you put in on the other petri dishes as you go on, but keep the amount of salt water the same
4. Move 10 brine shrimp into the 5 petri dishes
a) using a dropper
b) count the brine shrimp that are inside just by looking inside
5.
Checking the brine shrimp
a)I
took each petri dish with the different amounts of motor oil one at a time
under a microscope and counted how many were still living
b)They might not be moving around much, but check carefully to see if they are still kicking
c)Every 10 min. I counted how many were living out of 10
d) I continued each trial for 1 hour
e) Then I recorded how many brine shrimp had survived the trial at the last counting
The original purpose of
this experiment was to determine the effect of motor oil on the survival rate of
brine shrimp.
The average results of the experiment were that the brine shrimp that were held in the petri dish with 5% motor oil only had 85% living after 1 hour. The brine shrimp that where being held in the petri dish with 10% motor oil only had 83% living after 1 hour. The brine shrimp that were being held in the petri dish with 20% motor only had 76% living after 1 hour. The brine shrimp that were being held in the petri dish with 40% motor oil only had 76% living after 1 hour. The control group with no oil had 98% living after 1 hour.
CONCLUSION
My first hypothesis was that as the amount of motor oil in the water increased the survival rate of the brine shrimp would decrease.
The
results indicate that my first hypothesis should be accepted, because having
the motor oil increase did have the survival rate of brine shrimp decrease.
My
second hypothesis was that the more motor oil there was in the water the
shorter time the brine shrimp would survive.
The
results indicate that my second hypothesis should be accepted, because the more
motor oil there was in the water the shorter time the brine shrimp would
survive.
After
thinking about the results of this experiment, I wonder if antifreeze would
decrease the survival rate of brine shrimp even more than the motor oil did.
Antiifreeze is soluable in water and motor oil is not. I also wonder if I used
water from a different water source the results would change.
If I
were to conduct this project again I would probably add more motor oil in
with the brine shrimp to get bigger results.
Researched
by ---- Lyndsey S
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