Dissolved Oxygen for Fish Production, Lan Report Example

The Scientific Method

Dissolved oxygen is oxygen that is trapped in a fluid, such as water. Since many living organisms require 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 and then answer the questions below.

Make an observation – Based on the data in Table 4, describe the relationship between dissolved oxygen content and fish populations in the body of water. Discuss the pattern observed in the data set.

Answer = Based on the data in Table 4, it appears that as the number of fish observed increases, the amount of dissolved oxygen increases as well until a certain threshold population of fish are met. At around 12 fish, this amount of dissolved oxygen no longer rises proportional to the population.

Do background research – Utilizing at least one scholarly source, describe how variations in dissolved oxygen content in a body of water can affect fish populations.

Answer = Fish need a certain amount of dissolved oxygen to breathe. Therefore, water with more dissolved oxygen is able to support higher population of fish (Francis-Floyd, 2014).

Construct a hypothesis – Based on your observation in Question 1 and your background research in Question 2, develop a hypothesis statement that addresses the relationship between dissolved oxygen in the water sample and the number of fish observed in the body of water.

Answer = If there is a high amount if dissolved oxygen in the water, the environment will be able to support a high population of fish. If this oxygen is utilized by these fish, it will not be possible for larger populations to thrive.

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 = Several fish tanks will be set up in a manner that allows them to have the same amount of dissolved oxygen in the tank. The tanks will be closed off to prevent additional oxygen from entering the environment. Different amounts of fish will be put in each tank and observed to determine when the fish pass out. At this point, the experiment will end and the fish will be released to an environment with oxygen. The time point to the pass out will be taken for each fish. This will allow an examination of the relationship between number of fish and dissolved oxygen.

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 = A line graph would be needed to indicate the relationship between the variables.

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 = There is a positive trend that becomes a negative trend.

Draw conclusions – Interpret the data from the graph made in Question 6.  What conclusions can you make based on the results of this graph?

Answer = At a certain point, the level of oxygen dissolved in water prevents large numbers of fish from being able to survive.

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 this hypothesis because this data shows that different population sizes have different oxygen requirements.

References

Francis-Floyd R. (2014). Dissolved Oxygen for Fish Production. Retrieved from http://edis.ifas.ufl.edu/fa002