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Testing for Nitrogen
Procedure
1. Monitor Locally
| 1a. |
Select a local body of water (lake, stream, river, etc.) and an area of soil near the body of water. |
| 1b. |
Complete the site characterization worksheet. |
| 1c. |
Complete water and soil quality tests. |
| 1d. |
Record the data and answer all the questions on the Water and Soil Quality worksheet. |
| 1e. |
Write a Letter of Introduction. |
| 1f. |
Submit data to the project web site. |
Optional Extension:
Measure and compare the nitrogen levels
in soil and water before and after a significant rain event.
2. Monitor Remotely
In science books, the description of the photosynthesis process often focuses on terrestrial
plants. However, tiny plants in the water, called phytoplankton also need sunlight, food, water
and proper temperature to grow. Phytoplankton are the base level of the food web in the ocean,
absorb a large amount of CO2, and produce large amounts of O2. Since phytoplankton are so important
and can be an indicator of nutrient levels (nitrogen and phosphorus), the levels of phytoplankton in the ocean are
constantly monitored...from space. Satellites measure the amount of phytoplankton in the water
by measuring the chlorophyll-a produced by phytoplankton.
Use the Ocean Color Browser to access
real time phytoplankton levels in the ocean and answer the questions on the student worksheet.
(Purples and blues represent low levels, while reds represent high levels of phytoplankton, black
represents no data available). Note: if accessing this information during the first few days of the
month, it might be helpful to select the last day of the previous month to display a complete image.
| 2a. |
Are there any areas of the world's ocean that have low levels of phytoplankton? If so, where? |
| 2b. |
Are there any areas of the word's ocean that have high levels of phytoplankton? If so, where? |
3. Compare Seasons
Compare the levels of phytoplankton during different times of the year and answer the questions
on the student worksheet. (Note: Each link will open in a separate browser window to
allow for easier comparison of the images.)
| 3a. |
Which month does the ocean around Antarctica have the highest levels of phytoplankton? Explain. |
| 3b. |
Which month does the ocean around the Arctic have the highest levels of phytoplankton? Explain. |
| 3c. |
In the January image, the area of ocean around the Arctic are black. Explain. |
Assessment
Answer the following questions using the data on your Water and Soil Quality worksheet:
| 1. |
Were the tested levels of nitrogen in the soil and water within an
"acceptable" or "normal" range? |
| 2. |
Why do you think it is important to monitor locally for nutrients? |
| 3. |
What other water quality tests are important? Why? |
Use the Ocean Color Browser to answer
the following questions.
| 4. |
Where are large purple colored areas found? |
| 5. |
What does the purple area represent? |
| 6. |
Where are the majority of areas colored green and red, symbolizing
higher levels of phytoplankton found? |
| 7. |
Why do you think this is so? |
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