Coastal Ecosystems - Estuaries, Salt Marshes, Mangrove Swamps, Seagrasses
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 1. Coastal ecosystems are generally highly productive because a. they benefit from nutrient-rich runoff from land. b. benthic organisms can live in the upper photic zone. c. plants provide shelter. d. all of the above
____ 2. Human activities have wide-ranging potential effects on coastal ecosystems because a. trophic pyramids are unstable in coastal ecosystems. b. we can’t anticipate all the consequences of our many activities. c. the effects are immediately at hand with coastal ecosystems. d. both B and C
____ 3. Eutrophication is a. the trophic pyramid common to European estuaries. b. pollution that results from dumping toxins into the ocean. c. pollution that results from excess nutrients in the ocean. d. none of the above
____ 4. Factors that limit the productivity of estuary ecosystems include a. a lack of seawater. b. the need to survive osmotic stress. c. the depletion of the oxygen in the sediments. d. both B and C
____ 5. Estuary ecosystems act as nurseries for about ____% of commercial fish species. a. 25 b. 50 c. 75 d. 100
____ 6. Estuaries contribute to the productivity of surrounding marine ecosystems by a. providing a nursery for juvenile species. b. providing a steady stream of nutrients. c. allowing all sediment from storm runoff to reach them. d. both A and B
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____ 7. In the ____ marsh of a salt water marsh, organisms must deal with salt water as a regular part of the tidal cycle. The ____ marsh, by contrast, includes areas rarely flooded by tides. a. upper, lower b. inner, upper c. lower, upper d. outer, lower
____ 8. Adaptations that allow halophytes to survive in salt water include a. salt glands. b. stomata. c. sacrificial leaves. d. all of the above
____ 9. The two characteristics that make mangroves the basis for mangrove ecosystems include a. strong, tangled roots that provide habitats. b. the ability to hold soil in storm surges, waves, and weather. c. special sap that repels large predators. d. both A and B
____ 10. Seagrasses differ from other halophytes because a. they live entirely under water. b. they can live in deep water. c. they have the same internal salinity as seawater. d. all of the above
____ 11. Seagrass ecosystems differ from other halophyte-based ecosystems because a. they don’t require a freshwater source. b. they can exist in deep water. c. the seagrasses provide food for ecosystem inhabitants. d. all of the above
Short Answer
Provide a short answer to the following questions.
12. Explain why coastal ecosystems are generally highly productive. Why do human activities have wide-ranging potential effects on these ecosystems?
13. Explain eutrophication and why it is one of the biggest threats to coral reefs.
© Current Publishing Corp. 2006. All rights reserved. Reprinted with permission of Current Publishing Corp.

14. What factors limit the productivity of estuary ecosystems?
15. Explain how estuaries contribute to the productivity of surrounding marine ecosystems. For about what percentage of commercial fish do estuary ecosystems serve as nurseries?
16. Contrast and compare the differences in conditions between the upper marsh and lower marsh of a salt marsh.
17. List the adaptations halophytes use to survive in salt water. What is the advantage of being a halophyte?
18. List the two characteristics that make mangroves the basis for mangrove ecosystems.
Explain how these characteristics contribute to the ecosystem.
19. Compare and contrast seagrasses with other halophytes. Compare and contrast seagrass ecosystems with other halophyte-based ecosystems.
© Current Publishing Corp. 2006. All rights reserved. Reprinted with permission of Current Publishing Corp.

Coastal Ecosystems - Estuaries, Salt Marshes, Mangrove Swamps, Seagrasses
Answer Section
MULTIPLE CHOICE
1. ANS: D PTS: 1 DIF: Easy
TOP: High Productivity Marine Environments
OBJ: Why are coastal ecosystems generally highly productive?
KEY: ecosystem
2. ANS: D PTS: 1 DIF: Average
OBJ: Why do human activities have wide-ranging potential effects on coastal ecosystems?
TOP: High Productivity Marine Environments
3. ANS: D PTS: 1 DIF: Easy
TOP: High Productivity Marine Environments
OBJ: What is eutrophication?
KEY: eutrophication
4. ANS: D PTS: 1 DIF: Average
OBJ: What factors limit the productivity of estuary ecosystems?
TOP: Estuaries KEY: estuary
5. ANS: C PTS: 1 DIF: Easy
OBJ: For about what percentage of commercial fish species do estuary ecosystems serve as nurseries?
TOP: Estuaries KEY: estuary
6. ANS: D PTS: 1 DIF: Average
OBJ: How do estuaries contribute to the productivity of surrounding marine ecosystems?
TOP: Estuaries KEY: estuary
7. ANS: C PTS: 1 DIF: Easy
OBJ: How do conditions differ in the upper marsh compared to the lower marsh of a salt marsh?
TOP: Salt Marshes
8. ANS: D PTS: 1 DIF: Average
OBJ: What adaptations allow halophytes to survive in salt water?
TOP: Salt Marshes KEY: halophyte | stomata
9. ANS: D PTS: 1 DIF: Average
OBJ: What tow characteristics of mangrove trees make them the basis for mangrove ecosystems?
TOP: Mangrove Swamps KEY: mangroves
10. ANS: D PTS: 1 DIF: Average
OBJ: How do seagrasses differ from other halophytes? TOP: Seagrasses
KEY: halophyte | seagrasses
© Current Publishing Corp. 2006. All rights reserved. Reprinted with permission of Current Publishing Corp.

11. ANS: D PTS: 1 DIF: Average
OBJ: How do seagrass ecosystems differ from other halophyte-based ecosystems?
TOP: Seagrasses KEY: halophyte | seagrasses
SHORT ANSWER
12. ANS:
Coastal ecosystems are generally highly productive because they benefit from nutrients in runoff water and they’re shallow, providing ample light and shelter because plants can grow in many coastal ecosystems. Human activities have wide-ranging potential effects because humans tend to live close to the coast and because the effects aren’t always obvious in advance.
PTS: 1 DIF: Average
OBJ: Why are coastal ecosystems generally highly productive? | Why do human activities have wide-ranging potential effects on coastal ecosystems?
TOP: High Productivity Marine Environments KEY: ecosystems?_
13. ANS:
Eutrophication is an over abundance of nutrients caused by fertilizer runoff or other pollutants. Eutrophication can cause red tides. It is one of the biggest threats to coral reefs because a rise in nutrients allows algae that compete with coral to overgrow coral. It also increases plankton growth, blocking the light that coral needs.
PTS: 1 DIF: Average OBJ: What is eutrophication?
TOP: High Productivity Marine Environments KEY: eutrophication
14. ANS:
Salinity ranges and decomposition limit the productivity of estuary ecosystems. Organisms that do not tolerate wide salinity ranges can only live in limited areas in an estuary.
Decomposition tends to deplete oxygen in nutrient rich sediments.
PTS: 1 DIF: Average OBJ: What factors limit the productivity of estuary ecosystems?
TOP: Estuaries KEY: estuary
15. ANS:
Estuaries contribute to the productivity of surrounding marine ecosystems by providing a habitat and nursery for juvenile marine species. Estimates show that about 75% of commercial fish species rely on estuaries as nurseries.
PTS: 1 DIF: Average
OBJ: For about what percentage of commercial fish species do estuary ecosystems serve as nurseries? | How do estuaries contribute to the productivity of surrounding marine ecosystems?
© Current Publishing Corp. 2006. All rights reserved. Reprinted with permission of Current Publishing Corp.

TOP: Estuaries KEY: estuary
16. ANS:
The upper marsh is rarely flooded by salt water, so organisms that cannot tolerate much osmotic stress can live there. The lower marsh is regularly flooded by salt water, so organisms living there must have adaptations to surviving in salt water.
PTS: 1 DIF: Average
OBJ: How do conditions differ in the upper marsh compared to the lower marsh of a salt marsh?
TOP: Salt Marshes
17. ANS:
Halophytes have glands that secrete salt, pores that obtain oxygen from salt water and sacrificial leaves that eliminate salt. The advantages of being a halophyte include the ability to survive in salt water, and not being a common food plant for herbivores.
PTS: 1 DIF: Average
OBJ: What adaptations allow halophytes to survive in salt water?
TOP: Salt Marshes KEY: halophyte
18. ANS:
The two characteristics that make mangroves the basis for mangrove ecosystems are their strong, tangled root systems and that they’re large plants. The root systems provide a habitat for many species, including juveniles. Their large size helps them hold soil, trapping nutrients and protecting the coast from wave erosion.
PTS: 1 DIF: Average
OBJ: What two characteristics of mangrove trees make them the basis for mangrove ecosystems?
TOP: Mangrove Swamps KEY: mangroves
19. ANS:
Seagrasses differ from other halophytes by being entirely submergent. They do not have methods for excreting salt, but have an internal salinity the same as the surrounding water.
Unlike other halophyte systems, seagrass ecosystems don’t require a source of fresh water and can exist in deep water. Seagrasses also provide a food source for marine organisms, whereas most other halophytes do not.
PTS: 1 DIF: Average
OBJ: How do seagrasses differ from other halophytes? | How do seagrass ecosystems
TOP: Seagrasses KEY: differ from other halophyte-based ecosystems? halophytes | seagrasses
© Current Publishing Corp. 2006. All rights reserved. Reprinted with permission of Current Publishing Corp.