Exercise 1: The Scientific Method
Dissolved oxygen is oxygen that is trapped in a fluid, such as water. Since many living organism requires oxygen to survive, it is a necessary component of water systems such as streams, lakes and rivers in order to support aquatic life. The dissolved oxygen is measured in units of parts per million (ppm). Examine the data in Table 4 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.
1. Make an observation – Based on the data in Table 4, discuss what patterns you observe in regards to dissolved oxygen content and fish populations in the body of water?
Answer = My observation of the chart is that dissolved oxygen is needed fro fish to survive. The more oxygen in the water the more fish that are available for observation.
2. Do background research – Utilizing at least one scholarly source, describe how the dissolved oxygen content in a body of water can effect fish populations.
Answer = “Total dissolved gas concentrations in water should not exceed 110 percent. Concentrations above this level can be harmful to aquatic life. Fish in waters containing excessive dissolved gases may suffer from “gas bubble disease”; however, this is a very rare occurrence” (KY Water Watch). Its important to have a good level of O2 in water, to much will cause fish to die and to little will keep them from thriving.
3. Construct a hypothesis – Based on your observation in question 1 and your background research in question 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?
Answer = One hypothesis for this chart can be the higher the level of dissolved oxygen in the water the higher the amount of fish there are to observe. If the dissolved oxygen is too much for the amount of fish, than you have less fish to observe.
4. Test with an experiment – Describe an experiment that would allow you to test your hypothesis from question
3. This description must provide ample detail to show knowledge of experimental design and should list the independent and dependent variables, as well as your control.
Answer = One way to experiment this theory would be to put a tank together set up in such a way that it would represent a body of water in nature. Start out with no dissolved oxygen and a few fish than up the amount of Dissolved oxygen slowly to see the affect on the fish as well as the reproduction cycle as the levels rise.
5. Analyze results – Assume that your experiment produces results identical to those seen in Table 4, what type of graph would be appropriate for displaying the data and why?
Answer = I would use a line graph because it would allow me to see the level of dissolved oxygen against the amount of fish observed.
6. Analyze results – Graph the data from Table 4 and describe what your graph looks like (you do not have to submit a picture of the actual graph!).
Answer = My graphs shows a rise is the amount of fish that are observed as the level of dissolved oxygen increases but than the number of fish observed decreases which only leaves me to believe that the dissolved oxygen level was a little to much for the amount of fish.
7. Draw conclusions – Interpret the data from the graph made in Question 7. What conclusions can you make based on the results of this graph?
Answer = The conclusion I have made based on the data from the graph would be that there needs to be a safe level of dissolved oxygen in the water in order to maintain a healthy fish population.
8. Draw conclusions – Assuming that your experiment produced results identical to those seen in Table 4, would you reject or accept the hypothesis that you produced in question 3? Explain how you determined this.
Answer = I would accept the hypothesis from question 3 because in fact there needs to be a certain level of dissolved oxygen to the amount of fish. If the level of dissolved oxygen becomes way greater than the amount of fish, the fish will die off. There needs to be perfect levels of oxygen to the amount of fish involved.
Any sources utilized should be listed here.