1. what is hypoxia?
a. reduction in water levels
b. depletion of oxygen
c. having excess sediment in the water
d. a form of run off

2. what are the main pollutants that contribute to hypoxia in water?
a. organic chemicals
b. infectious agents
c. plant nutrients
d. metals

3. in the gulf of mexico hypoxia results from agricultural chemicals used in various us states.
true or false?

4. why is a hypoxic zone sometimes called a dead zone?
a. fish and other water organisms cannot live without sufficient oxygen
b. people cannot swim in the water
c. algae will not grow in the water
d. the water contains many bacteria and viruses

5. hypoxia in the gulf of mexico is an example of point source pollution.
true or false?

6. how do wetlands control hypoxia?
a. contribute nutrients to the water
b. contribute sediment to the water
c. speed up the flow of water
d. filter nitrogen and phosphorus from the water

7. controlling sewage water can control hypoxia.
true or false?