unit 1

Hypoxia is

• a large trash pile in the Pacific Ocean

• low oxygen and is primarily a problem for estuaries and coastal waters.

• excessive oxygen in the water near the coast

What is Eutrophication?

• Polluted ocean water

• A process when the ocean water gets too hot and everything dies.

• A process in which a body of water gets too many nutrients, such as phosphorus and nitrogen

The main nutrients that are of concern in nonpoint pollution are

• sodium and chlorine

• potassium and nitrogen

• nitrogen and phosphorous

Nonpoint source pollution is:

• not happening in Virginia and it's rivers

• runoff that goes into our, drains, ground waters, rivers and estuaries.

• due to factories and sewage treatment plants

What nutrients increase the rate of algae growth and reproduction in aquatic ecosystems?

• nitrates and phosphates

• sulfates and ammoniates

• philates and sulfates

• phosphates and communicates

Which type of pollution can lead to harmful "algal blooms"?

• thermal pollution

• oil spills

• nutrient pollution

• bacteria

The Mississippi River carries agricultural runoff to the Gulf of Mexico.  What phenomenon results?

• a dead zone
• regular flooding of the Mississippi delta
• return of mining refuse water
• Gold tides

How do bacteria affect Dissolved Oxygen (DO) in water bodies?

• increase DO through decomposition

• decrease DO through decomposition

• DO stays the same

• bacteria multiply DO by 8

Most estuarine organisms are ____________________________, meaning they can tolerate a wide range of salinity. They can survive extreme changes in salinity.

• freshwater only

• stenohaline

• brackish water only

• euryhaline

Fish are ectotherms. What does this mean?

• their body temperature is the same as the water temperature

• their body temperature is always higher than the water temperature

• their body temperature is always lower than the water temperature

• their body temperature is not influenced by the water temperature