Lab 1

Exercise 1:

Dissolved oxygen is oxygen that is trapped in a fluid, such as water. Since virtually every living organism requires oxygen to survive, it is a necessary component of water systems such as streams, lakes and rivers in order to support aquac life. The dissolved oxygen is measure in units of ppm—or parts per mil- lion. Examine the data in Table 2 showing the amount of dissolved oxygen present and the number of fish observed in the body of water the sample was taken from; finally, answer the questions below.

Lab 1 : Scientific Method

Table 2: Water Quality vs. Fish Population

Dissolved Oxygen (ppm) | 0 | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 |

Number of Fish Observed | 0 | 1 | 3 | 10 | 12 | 13 | 15 | 10 | 12 | 13 |

1. Based on the information in Table 2, what patterns do you observe?

a. there is an increase in the amount of dissolved oxygen with an increased number of fish.

b. something happens after the observation of 15 fish that decreases the fish population back down to 10 fish yet the amount of dissolved oxygen is still consistent with the original rate of increase.

2. Develop a hypothesis relating to the amount of dissolved oxygen measured in the water sample and the number of fish observed in the body of water.

My hypothesis would be that the greater number of fish in the water would indicate a greater amount of dissolved oxygen

3. What would your experimental approach be to test this hypothesis?

To test this I would divide a body of water into two parts. One part would have a specific number of fish put in and the other would not have any fish. I would measure the dissolved oxygen in both parts. I would check my readings with each additional fish that would be placed into water while at the same time monitoring the body of water that had no fish.

4. What are the independent and dependent variables?

Independent variable would be the amount of dissolved oxygen within the body of water. The...