Analyzing Abiotic Factors of the Ocean
AP Environmental Science
Name ___________________________ Per. _____
Introduction
Abiotic factors are very important in influencing the types of organisms that can survive in a particular
ecosystem. In this activity, we will explore some of the most important abiotic factors in the ocean
ecosystem. We will explore how various abiotic factors change in the different zones of the ocean and
consider the implications for living organisms.
Note: The data provided for this laboratory activity were obtained using a Modular Microstructure Profiler
(MMP), which measures temperature, salinity, density and dissolved oxygen of the ocean at profiles down
to 300 meters in the ocean. The MMP data in this lab was obtained from 10N latitude, 95W longitude (off
the west coast of Guatemala).
Hypothesis
In the space below, predict five differences between the surface water of the ocean and the water in the
deep ocean with respect to biodiversity, water density, dissolved oxygen, salinity and temperature. Be sure
to write your hypothesis in If…, then… form.
Procedure
Analyze the data presented in the graphs to answer the analysis questions.
Note:
 For both graphs the units on the y-axis are megapascals, a unit of pressure. One megapascal is
equivalent to 100 meters of depth in the ocean (1Mpa = 100 m).
 For Figure 1: There are three separate x-axes. The first axis displays temperature (degrees Celcius), the
second axis displays salinity (parts per thousand) and the third axis displays density (kilograms per
cubic meter).
Analysis
Answer each question in the space provided using complete sentences.
1. What temperature is the water at the surface? What temperature is the water at 300 meters deep?
2. At what depth does temperature drastically decrease? Why does this drastic decrease in temperature
occur?
3. What is the salinity of the water at the surface? What is the salinity of the water at 300 meters deep?
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4. At what depth does salinity drastically increase? Why does this sudden increase in salinity occur?
5. What density is the water at the surface? What density is the water at 300 meters deep?
6. At what depth does density drastically increase? Why does this sudden increase in density occur?
7. Given the information presented, how is density of ocean water related to temperature and salinity?
8. How much dissolved oxygen is present at the surface? How much dissolved oxygen is present at 300
meters deep?
9. At what depth does dissolved oxygen drastically decrease? Why does this sudden decrease in dissolved
oxygen occur?
10. Identify the depths at which dissolved oxygen does not have a consistent trend with depth? Why would
these inconsistencies occur?
11. If you were an animal that eats kelp, at what approximate depth would you live?
12. If you were a species of animal that didn't have eyes, at what approximate depth would you live?
13. If you were an animal that can tolerate low salinity conditions, at what approximate depth would you
live?
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14. Describe the types of adaptations an organism would need to live at 300 meters below sea level to
tolerate the levels of each abiotic factor considered in this activity.
15. Describe the effects depth has on the abundance of organisms present. Explain why this is the case.
16 -18. Complete the conclusion as outlined on the following page. Staple to this packet.
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Conclusion
On a separate sheet of paper, write a conclusion paragraph based on the data you analyzed. In your
conclusion, identify the trends in the data and provide insight to explain those trends. Reflect on your
hypotheses. Support or refute your hypothesis based on your analysis of the data. Provide suggestions and
questions that would guide further research related to the data you analyzed.
Graphs
Figure 1: The Effects of Ocean Depth on Temperature,
Salinity and Density
Salinity
Figure 2: The Effects of Ocean Depth on
Dissolved Oxygen
Temperature
Density
50 M
100 M
150 M
200 M
250 M
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