Compare the healthy ocean on the left with the dead zone on the right.
Healthy Ocean | Dead Zone | |
|---|---|---|
Nutrients from runoff | ||
Algae | ||
Oxygen | ||
Fish & marine life |
Explain dead zones, overfishing, and by-catch, and describe how each one harms marine ecosystems.
Describe the steps that create a dead zone.
Make an argument for which fishing method is most sustainable and why.
If you need help with this assignment, click here for the class recording.
Explain dead zones, overfishing, and by-catch, and describe how each one harms marine ecosystems.
Describe the steps that create a dead zone.
Make an argument for which fishing method is most sustainable and why.
If you need help with this assignment, click here for the class recording.
Marine: This word describes anything connected to salt water, ocean ecosystems, or ocean life such as marine animals, marine plants, or marine environments.
Think about it: What are the basic requirements for marine life?
Compare the healthy ocean on the left with the dead zone on the right.
Healthy Ocean | Dead Zone | |
|---|---|---|
Nutrients from runoff | ||
Algae | ||
Oxygen | ||
Fish & marine life |
Place the steps of dead zone formation in order:
Decomposition: Dead algae broken down by bacteria
Hypoxia: Low oxygen creates dead zones where marine life can't survive
Oxygen depletion: Increased bacteria use up oxygen in the water
Algae bloom: Rapid growth of algae due to extra nutrients
Eutrophication: Increased nutrients from agricultural runoff and sewage
A student argues: "But Mrs. Winer! If algae performs photosynthesis, there should be increased oxygen in the water."
What is the best explanation for why this doesn't occur in a dead zone?
The map above marks areas that are eutrophic (areas of low oxygen) and hypoxic (dead zone). Zoom out and explore the map.
What do you notice about the locations of eutrophic and hypoxic areas? Where are the majority located?
Another major threat to marine life is overfishing.
Click on the infographic to make it bigger:
What is overfishing?
By-catch is when people accidentally catch animals they didn't mean to catch.
Click on the infographic to make it bigger:
Which of these is an example of by-catch?
Learn about different commercial fishing methods:
If you were a fisherman, which method would you choose and why?
Include at least 1 advantage and 1 disadvantage.
Reflect on your understanding of the learning objectives:
Explain dead zones, overfishing, and by-catch, and describe how each one harms marine ecosystems. |
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Reflect on your mastery of the success criteria:
Describe the steps that create a dead zone. | |
|---|---|
Make an argument for which fishing method is most sustainable and why. |
What marine organisms produce the oxygen that other ocean life needs?
What is eutrophication?
Why does excessive surface algae growth reduce oxygen for deeper plants?
Which human source is a major contributor of nutrients that cause the Gulf dead zone?
What short term solutions could help reduce dead zones?
Which long-term solution will require a change in agriculture to prevent dead zones?
Why is by-catch a concern?
Which region of the world produces the largest amount of by-catch?