18. Water is brought to an estuary from a variety of sources. Which of the following would contribute to an increase in the salinity of the estuary?
1 point
A. rivers
B. streams
C. tides
D. urban run-off
19. What kind of habitat is the ocean covered and uncovered as the tide goes in and out?
1 point
A. estuaries
B. food web
C. food chain
D. intertidal zones
20. How do organisms exposed to air be able to prevent drying out?
1 point
A. They completely seal their shells.
B. They move up to zones that have plenty of water.
C. Organisms feed on other organisms that are watery.
D. Organisms store much water in their bodies.
21. What factors may affect the salinity of water across the intertidal zone?
1 point
A. amount of rainfall and evaporation
B. kinds of organisms living in the area
C. availability of space and food
D. runoff from the people living along the shoreline
22. Which best describes the water in an estuary?
1 point
A. brackish
B. fresh
C. frozen
D. salt
23. Which characteristic distinguishes an estuary from other bodies of water?
1 point
A. animal life
B. dissolved oxygen
C. plant life
D. salinity level
24. Which would be the impact on the environment if there were no estuaries?
1 point
A. There would be drought.
B. There would be more pollutants in the oceans.
C. There would be decreased concentration of salt in the oceans.
D. There would be less boating, fishing and swimming in local rivers.
25. Which characteristic of estuary makes it a good nursery area for marine organisms?
1 point
A. It is located at the mouth of a river.
B. It has many area to hide from predators.
C. It has a mix of salt and freshwater.
D. It has the ability to absorb water and prevent flooding.