Download Marine Ecosystems

Section 3: Aquatic Ecosystems
Aquatic ecosystems are grouped based on abiotic factors such
as water flow, depth, distance from shore, salinity, and latitude.
Essential Questions
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What are the major abiotic factors that determine the aquatic ecosystems?
What are transitional aquatic ecosystems and why are they important?
What are the zones of marine ecosystems?
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Aquatic Ecosystems
Vocabulary
Review
New continued
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salinity
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sediment
littoral zone
limnetic zone
plankton
profundal zone
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wetlands
estuary
intertidal zone
photic zone
aphotic zone
benthic zone
abyssal zone
Aquatic Ecosystems
The Water on Earth
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Aquatic environments are divided into freshwater and marine ecosystems.
Only about 2.5 percent of the water on Earth is freshwater.
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Aquatic Ecosystems
Freshwater Ecosystems
Rivers and streams
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Water in rivers and streams flow in one direction.
The slope of the landscape determines the direction and speed of the water.
Sediment is the material that is deposited by water, wind, or glaciers.
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Aquatic Ecosystems
Freshwater Ecosystems
Rivers and streams
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Interactions between land and water result in differences in erosion, nutrient
availability, and species composition and diversity along the course of the
water.
• Fast moving water: less sediment and organic matter; fewer species
• Slow moving water: sediment is deposited as mud, silt, and sand;
supports a diversity of plant and animal species
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Aquatic Ecosystems
Freshwater Ecosystems
Lakes and ponds
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An inland body of standing water is called a lake or pond.
The temperature of lakes and ponds varies depending on the season.
Turnover in lake water circulates nutrients and oxygen between water depths
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Aquatic Ecosystems
Freshwater Ecosystems
Lakes and ponds
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Lakes and ponds are divided into three zones based on the amount of
sunlight that penetrates the water.
The littoral zone is closest to shore, shallow, and sunlight reaches the
bottom.
The littoral zone is a highly productive area, with numerous producers.
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Aquatic Ecosystems
Freshwater Ecosystems
Lakes and ponds
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The limnetic zone is an open water area that is well lit.
Production is dominated by plankton, free-floating autotrophs
Home to many freshwater fish
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Aquatic Ecosystems
Freshwater Ecosystems
Lakes and ponds
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The profundal zone is the deepest part of a lake or pond.
Little light penetrates through the limnetic layer
Colder and lower in oxygen
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Aquatic Ecosystems
Transitional Aquatic Ecosystems
Wetlands
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Areas of land such as marshes, swamps, and bogs that are saturated with
water and that support aquatic plants are called wetlands.
Wetlands have high levels of species diversity.
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Aquatic Ecosystems
Transitional Aquatic Ecosystems
Estuaries
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An estuary is where freshwater from a stream or river meets saltwater from
the ocean.
Estuaries can support a variety of habitats, such as mangrove forests or salt
marshes.
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Aquatic Ecosystems
Marine Ecosystems
Intertidal zone
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The intertidal zone is a narrow band where the ocean meets land.
Organisms must adapt to daily changes in tides and wave action.
The intertidal zone is further divided into vertical zones.
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Aquatic Ecosystems
Marine Ecosystems
Open ocean ecosystems
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The open ocean is divided into three zones: pelagic, abyssal, and benthic.
The pelagic zone is further divided into two zones
The photic zone is shallow enough that sunlight is able to penetrate.
The aphotic zone is an area that sunlight is unable to penetrate.
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Aquatic Ecosystems
Marine Ecosystems
Open ocean ecosystems
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The benthic zone is the area along the ocean floor.
In shallow areas, the benthic zone receives sunlight, as depth increases,
light and temperature decrease.
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Aquatic Ecosystems
Marine Ecosystems
Open ocean ecosystems
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The deepest region of the ocean is called the abyssal zone.
Water is very cold, and there is no light penetration
Organisms depend on food materials that sink from the surface
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Aquatic Ecosystems
Marine Ecosystems
Coastal ocean and coral reefs
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Coral reefs are one of the most diverse ecosystems on Earth.
Widely distributed in warm shallow marine waters
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Aquatic Ecosystems