module 8

In the Gulf of Mexico, hypoxia occurs in winter.

false

Which process removes oxygen from water in hypoxic zones?

decaying plankton

Which of the following correctly expresses the relationship between decomposition and dissolved oxygen?

Decomposition uses dissolved oxygen, removing it from the water

How do excess nutrients in the Gulf of Mexico affect plankton?

allows them to grow to higher than usual levels

Which of the following is not a source of nitrogen and phosphorous to a river?

burning fossil

What does DO stand for?

dissolved oxygen

In order to solve problems associate with Gulf of Mexico "dead zone", the followings can be done: Change flood control practices Use ____________ more efficiently Control discharges of nitrogen Create and restore wetlands Reduce nutrient loading Manage the whole system

fertilizers

Which of the following would help reduce the dead zone in the Gulf of Mexico?

improved agricultural technologies that reduce nutrient inputs to rivers

Where are dead zones found throughout the world?

in many places worldwide

An excess of which of the following would most likely be associated with the formation of a dead zone?

nitrogen

The depletion of which essential element is responsible for the Gulf of Mexico dead zone?

oxygen

The term "anoxic" refers to an absence of what?

oxygen

What is the primary culprit behind the dead zone in the Gulf of Mexico?

sewage discharge agricultural chemicals