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Dead Zones

A place where life dies
Image result for Dead zones

“The sea is the universal sewer.”

~Jacques Yves Cousteau, Oceanographer

                                              


DISCUSSION

    “Dead Zones” is another term for hypoxia, meaning there is a reduced oxygen level in the water of the ecosystem.  Every kind of ecosystem is able to have a dead zone, but they are most commonly found in oceans.  These zones are uninhabitable, and animals that are lucky enough when coming across them will leave, while the more commonly unlucky ones are suffocated and killed.  Although dead zones can be found in many areas in the United States, the most commonly known locations are in the East Coast, the Great Lakes, and the Gulf of Mexico (where the second largest dead zone in the world is located).

 

KEY VOCABULARY

  • Hypoxic (zones)- areas in the ocean of low oxygen

  • Suffocate- die or cause to die from lack of air or inability to breath

  • Chemical run-off- the draining away of water (or substances carried into in) from the surface of an area of land, a building or structure, etc.

  • Decomposition- the state or process of rotting; decay

  • Pollution- the presence in or introduction into the environment of a substance or thing that has harmful or poisonous effects

  • Stimulate- raises levels of physiological or nervous activity in (the body or any biological system)



SUMMARY

  • Dead zones are areas of the ocean where oxygen is not as prominent as in other areas

  • This makes it impossible for life forms to prosper

  • Many life forms either die or have to move to different parts of the ocean as the result of the loss of oxygen

  • Some major dead zones around the world are Lake Erie, the Chesapeake Bay, the Gulf of Mexico, and the Baltic Sea.

  • Some areas go through dead zones periodically

  • One major cause of dead zones is the fertilizer that some farming communities use. The fertilizer flows into the ocean and kills the oxygen in a certain area, making it impossible to sustain life.



VIDEO

http://oceantoday.noaa.gov/happnowdeadzone/

EXPLORE MORE

  • Every kind of lake or ecosystem is susceptible to become a dead zone

  • There is a dead zone in the Gulf of Mexico

  • The Baltic Sea

    • Home to 7 of the world’s 10 Largest Dead Zones

  • Why Do Dead Zones Happen?

    • Excessive nutrient pollution from human and natural activities that cause mass oxygen depletion (hypoxia) in marine life and low bottom water

  • The largest dead zones are located all over the world

    • The entire bottom of the Baltic Sea

    • Lake Erie

    • Off the coast of Oregon

    • Chesapeake Bay 

REVIEW QUESTIONS

  1. What is the other word for a “Dead Zone”?
  2. Why are there no living organisms in Dead Zones?
  3. Where are they most commonly located?
  4. What are the most well known Dead Zones?
  5. Why is it important to know about Dead Zones?

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