Homework II Oceanic Dead Zones and the Decline of Corals
Due Friday, October 2nd in class
Responses must be typed
1. Follow the link below and listen to the story on NPR related to the decline of
corals.
http://www.npr.org/templates/story/story.php?storyId=17243164
Questions to address:
Carbon dioxide dissolved in water produces _____________________
When is it estimated that coral reefs might disappear?
What other factor related to climate change also is affecting coral reefs?
When coral reefs die or disappear, what organisms take over?
What is the current concentration of CO2 in the atmosphere?
What is the expected CO2 concentration by mid-century?
How does increased atmospheric CO2 affect corals?
What other kinds of organisms are also susceptible?
When was the last time corals disappeared from earth?
How long did it take for them to return?
2. The following is an excerpt from a news story from June 21 by the AP
concerning recent Mid-west flooding and its potential impact on the dead zone
in the Gulf of Mexico.
Flood, size of gulf dead zone linked
Extra farm runoff in the Mississippi to increase area with no oxygen
Associated Press
June 21, 2008
WASHINGTON - Floodwaters loaded with farm runoff are heading down the Mississippi River,
and scientists fear that the deluge will sharply increase the expected dead zone this summer in
the Gulf of Mexico, covering an area the size of Maryland.
The dead zone is a region of the gulf that becomes starved for oxygen during much of the
summer and cannot support fish or other sea life.
There are hundreds of dead zones around the world that wreak havoc on marine ecology and cut
off vast areas for commercial fishing. The zone in the gulf is the largest in the Western
Hemisphere.
Essentially what this story is communicating is that agricultural run-off in the
Mississippi is entering the Gulf of Mexico creating low oxygen conditions over wide
areas.
Using internet resources and any others you might find helpful, answer the following
questions relating to dead zones in the worlds oceans.
What is in the river water that is ultimately causing development of
dead zones?
What type of organisms (aerobic or anaerobic) cause low oxygen
conditions?
What process that occurs in lakes is essentially identical to the
formation of dead zones?
How can dead zones be remediated?
Name three places where significant dead zones are found.
How large and extensive is the Gulf of Mexico dead zone? Include a
map, if possible.