Learning Objectives and Study Questions
Chapter 12: Withgott and Laposata, 5th ed.
1. Rank the following freshwater reservoirs from largest to smallest: atmosphere, glaciers and ice caps,
groundwater, lakes, and rivers.
2. Describe the conditions under which groundwater can become surface water and vice versa.
3. Calculate a stream’s discharge given data on the cross-sectional area of its channel and its average velocity.
4. Sketch the general pattern of surface currents in Earth’s oceans and the more complex thermohaline
circulation of its surface and deep waters.
5. Outline the causes and consequences of El Niño and La Niña conditions.
6. Recognize the following coastal or marine environments from descriptions or photographs and briefly
describe the ecosystems and ecological benefits characteristic of each: coral reefs, estuaries, intertidal
zones, kelp forests, mangrove swamps, and salt marshes.
7. List the most and least biologically-productive parts of the open-ocean pelagic environment and explain
why each has the productivity it does.
8. Contrast consumptive with nonconsumptive uses of water and give an example of each.
9. Cite two positive and two negative environmental effects of damming a river and creating a reservoir.
10. Outline two potential solutions to humanity’s depletion of fresh surface and groundwater.
11. Contrast point source and non-point source sources of water pollution and give an example of each.
12. Briefly describe the sources and effects of water pollution by: toxic chemicals, pathogens, excess nutrients,
biodegradable waste, sediment, oil, plastic debris, and heat (thermal pollution).
13. Outline the steps used to treat wastewater before it is returned to the environment.
14. Define bycatch and predict how much of a given commercial harvest of fish is likely to be bycatch.
1. Of the major freshwater reservoirs on Earth _____ are the smallest.
A. atmosphere
B. glaciers and ice caps
C. groundwater
D. lakes
E. rivers
2. Groundwater naturally flows out to become surface water at _____, places where the water table intersects
the ground surface.
A. artesian wells
B. confined aquifers
C. recharge areas
D. springs
E. wells
3. A stream with a cross-sectional channel area of 5.2 m2 and an average velocity of 0.5 m/s will have a
discharge of _____ m3/s.
A. 0.5
B. 2.6
C. 5.2
D. 10.4
E. indeterminate, we cannot tell from the data given
4. Between about 0° and 60°N surface currents circulate _____ in Earth’s oceans.
A. clockwise
B. counterclockwise
C. erratically
D. in seasonally-variable directions
E. little if at all
5. El Niño conditions are associated with all of the following except _____.
A. decreased upwelling along the western coast of South America
B. greater marine productivity along the western coast of South America
C. warming of surface water in the equatorial Pacific
D. weakening of Trade Winds
E. actually, El Niño is associated with all of the above conditions
6. Abundant stands of brown algae (“seaweed”) that provide food and shelter for marine organisms and help
dissipate storm energy and minimize coastal erosion are the hallmarks of _____.
A. estuaries
B. intertidal zones
C. kelp forests
D. mangrove swamps
E. salt marshes
7. Even in the tropics open-ocean pelagic environments tend to have low productivities because of a lack of
_____.
A. dissolved salts (Na, Cl, K, Mg, etc.)
B. nutrients
C. political will
D. sunlight
E. warm water
8. All of the following are consumptive uses of water except _____.
A. dust abatement at building sites
B. growing crops
C. hydroelectric power generation
D. providing municipal drinking water
E. watering livestock
9. When tailwater runs off agricultural fields and back into an adjoining stream or river we are likely to see
pollution by _____.
A. biodegradable waste
B. excess nutrients
C. heat
D. sediment
E. all of the above
10. If a large commercial fishing vessel hauls in 50 metric tons of fish, how much is likely to be bycatch?
A. 1.7 tons
B. 5.0 tons
C. 8.5 tons
D. 12.5 tons
E. 17.0 tons