Section 2 Aquatic Ecosystems Chapter 21 Objectives Describe the major aquatic ecosystems. Identify...

Section 2 Aquatic EcosystemsChapter 21

Objectives

Describe the major aquatic ecosystems.

Identify major biotic and abiotic factors associated with different aquatic ecosystems.

Compare the ocean and freshwater zones.


Ocean Zones

Photic zone in the ocean receives light (top 100 m) Water absorbs light

Aphotic zone does not Most of the ocean Photosynthesis does not occur

Other zones of the ocean are defined based on their relative locations.


Ocean Zones, continued

The Intertidal Zone Area of shoreline covered in

water at high tide and exposed during low tide.

Organisms must be able to tolerate drying and pounding by waves. Crabs, clams, mussels,

oysters, sea anemones, sea stars

Chapter 21Intertidal Zone

Section 2 Aquatic Ecosystems



The Neritic Zone The neritic zone receives nutrients from

the bottom of the ocean and from land. It is the ocean’s richest zone in terms of the number of species and individuals.

Plankton, fish, sea turtles

Chapter 21Neritic Zone




The Oceanic Zone Deepest parts of the ocean with fewer

species. Production in the oceanic zone is limited

by a shortage of nutrients. Photic zone producers: protists, bacteria,

plants, invertebrates. Photic zone consumers: fish, mammals such as

whales, large invertebrates. Aphotic producers: chemosynthetic bacteria

(feed tubeworms) Aphotic consumers: squid, fish

Adaptations:

•Large eyes•Sensitive vision•Barbed arms with photophores •webbing

Chapter 21Oceanic Zone




Estuaries Estuaries are very productive areas where

rivers and streams flow into the sea. Variations in temperature and salinity Impacted by tide changes


Freshwater Zones

Lakes and Ponds Oligotrophic lakes are clear and lacking

in nutrients. Eutrophic lakes are rich in nutrients and

are often murky. Both contain fish, otter, muskrat, ducks,

loons, turtles, snakes, salamanders, frogs.

Chapter 21

Three Lake Zones


Section 2 Aquatic EcosystemsChapter 21Freshwater Zones,

continued Rivers and Streams

Rivers and streams are bodies of water that flow down an elevation gradient within a watershed. Insect larvae attach to rocks, fish adapted to

swim upstream against powerful currents.Stream River

Section 2 Aquatic EcosystemsChapter 21Freshwater Zones,

continued Freshwater Wetlands

Freshwater wetlands are areas of land, such as marshes and swamps, that are covered with fresh water for at least part of each year. Marshes: nonwoody plants (cattails) Swamp: woody plants

Most productive freshwater ecosystem. Birds, fish, mammals, amphibians, invertebrates,

reptiles. US wetlands have large predators like American

alligator, American crocodile, the Florida panther, the whooping crane.

Chapter 21Freshwater Biomes


Freshwater Wetlands

Significance Stopover for migrating birds Protect spawning organisms like fish Filter pollutants out of water Flood control

Everglades National Park

Multiple Choice

1. Why are estuaries more productive than most other biomes?A. Estuaries contain vast coniferous forests.B. Estuaries have shallow, nutrient-laden water.C. Estuaries get more sunlight than other biomes.D. The majority of land on Earth is covered by estuaries.

Standardized Test PrepChapter 21

Multiple Choice, continued

1. Why are estuaries more productive than most other biomes?A. Estuaries contain vast coniferous forests.B. Estuaries have shallow, nutrient-laden water.C. Estuaries get more sunlight than other biomes.D. The majority of land on Earth is covered by estuaries.



2. Which of the following characterizes the neritic zone of the ocean?F. It receives little sunlight.G. It supports very few species.H. It is exposed to the air by low tide.J. It receives nutrients washed from land.



3. Which of the following is true of temperate deciduous forests?A. They are found near the equator.B. They have the lowest rainfall of any biome.C. They undergo seasonal changes in temperature.D. They have the highest species richness of any biome.



4. Which of the following best describes the water of all eutrophic lakes?F. coldG. saltyH. murkyJ. lifeless



Use the graph below to answer question 5. The graph shows the relative temperature, precipitation, and soil nutrient content in a specific biome.



5. Which of the following biomes is best represented by this graph?A. tundraB. desertC. tropical rain forestD. temperate grassland



Complete the following analogy:

6. grasses : savanna :: coniferous trees :F. taigaG. tundraH. desertJ. temperate deciduous forest



Use the graph below to answer question 7. The graph ranks several types of biomes in terms of their relative productivity.



7. If a scientist needed to add a bar representing the temperate grassland biome to this graph, where should the bar be placed?A. to the left of desertB. between savanna and estuaryC. between estuary and tropical rain forestD. to the right of tropical rain forest


Short Response

Biomes are very large terrestrial ecosystems that contain a number of smaller but related ecosystems.

Describe how the major biomes are characterized.


Short Response, continued

Biomes are very large terrestrial ecosystems that contain a number of smaller but related ecosystems.

Describe how the major biomes are characterized.

Answer: The major biomes are distinguished by abiotic factors and by the presence of characteristic plants and animals.


Standardized Test PrepChapter 21Extended Response

Base your answers to parts A & B on the information below.

Ecologists recognize the following ecological zones in the ocean: photic, aphotic, intertidal, neritic, oceanic, pelagic, and benthic.

Part A Describe the factors used as a basis for distinguishing the zones.

Part B Relate these factors to the types of organisms that inhabit each zone.

Standardized Test PrepChapter 21Extended Response, continued

Answer:

Part A Factors used as a basis for distinguishing the ecological zones of the ocean are depth, distance from shore, and penetration of sunlight.

Part B Student responses should explain that the ocean can be divided into zones along a vertical axis on the basis of light penetration (photic and aphotic zones) or nearness to the bottom (benthic and pelagic zones), or along a horizontal axis on the basis of distance from shorelines (intertidal, neritic, and oceanic zones). Responses should also describe typical organisms and adaptations for each of these zones.

Section 2 Aquatic Ecosystems Chapter 21 Objectives Describe the major aquatic ecosystems. Identify...

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