The Oceans: Carbon Sink or Source?
Part B: Phytoplankton: Nature's Green Machines
Begin by watching a NASA video The Ocean's Green Machines. In addition to watching the video, read an accompanying NASA article entitled What Are Phytoplankton?
As you watch the video and read the article, take notes on the topics listed below. Your teacher may want to assign specific topics to individuals, which can then be shared within your group in a jigsaw activity.
- the role of phytoplankton in the carbon cycle
- what phytoplankton need to grow
- why scientists think it is important to study phytoplankton
- how do satellites measure phytoplankton blooms
- global locations where phytoplankton flourish and grow
- why phytoplankton flourish in some locations but not others
- the relationship between warmer oceans and phytoplankton productivity
- differences in phytoplankton growth from season to season and year to year
Next, watch a NASA visualization of a 10-year data set of phytoplankton growth. The satellite is measuring the amount of chlorophyll used by phytoplankton to photosynthesize. Pay careful attention to the phytoplankton bloomswhere they happen and any seasonal variability that you observe. Phytoplankton blooms are considered to be the "greening up" of the oceans. Hint: Paying attention to what the terrestrial vegetation is doing will give you a clue as to the seasonal variability. Reading the information on the website will help you interpret the visualization.
The colors are very important to observe;
Dark blue = very low phytoplankton numbers. No bloom.
Green to red = high phytoplankton numbers generating large blooms.
Now, use your notes from the movie, the article, and the visualization to help you answer the Checking In and Stop and Think questions, below.
Stop and Think1. A warmer climate produces warmer oceans. Phytoplankton reproduction requires important nutrients such as nitrates and phosphates. When oceans warm, the ability of deep ocean currents to bring these important nutrients up to the surface is reduced.
a. What effect(s), if any, would this have on phytoplankton reproduction, the biological pump, and the ocean as a large carbon sink?
b. What effects, if any, would this have on other parts of the carbon cycle?
- Have you ever wondered how NASA visualizations like the one on the right are created? If you have the time, watch this SciFri video Creating Earth
- Read the other articles on Phytoplankton and ocean research in the NASA Earth Observatory features collection. You can access these articles at here
- Grow your own phytoplankton and use it to design an experiment on variables that affect phytoplankton growth. Here is one of several videos that tells you How to grow phytoplankton.
- Carry out a case study on predicting the Spring Phytoplankton Bloom in the Gulf of Maine. When is Dinner Served? Predicting the Spring Phytoplankton Bloom in the Gulf of Maine