1. Chapter Seven: Aquatic Ecosystems

2. Section One: Freshwater Ecosystems
Lakes
Ponds
Rivers
Streams
Wetlands: where land is periodically under water

3. Section One: Freshwater Ecosystems
Characteristics of Aquatic Ecosystems
Temperature, Sunlight, Oxygen and Nutrients
Plankton: organisms that cannot swim against currents so they are drifters
Nekton: free swimming organisms
Benthos: bottom dwelling organisms

4. Section One: Freshwater Ecosystems
Lakes and Ponds
Littoral Zone: nutrient rich zone near the shore
Phytoplankton, ducks, reeds
Benthic Zone: bottom of a pond or lake
Decomposers, insect larvae, clams

5. Section One: Freshwater Ecosystems

6. Section One: Freshwater Ecosystems
How Nutrients Affect Lakes
Eutrophication: an increase in the amount of nutrients in an aquatic ecosystem
Happens naturally but can be sped up by runoff

7. Section One: Freshwater Ecosystems
Freshwater wetlands
Swamps and marshes
Absorb and remove pollutants from the water
Control flooding
Spawning of freshwater fish
Home for native and migratory wildlife

8. Section One: Freshwater Ecosystems
Marshes
Low flat lands, with little water movement
Benthic zones are nutrient rich
Salinity varies
Swamps
Occur on flat poorly drained land, often near streams
Reptiles are predators

9. Section One: Freshwater Ecosystems
Human Impact on Wetlands
Many were drained because they were considered breeding grounds for insects
Purifiers of wastewater
Flood prevention

10. Section One: Freshwater Ecosystems
Rivers
Mosses are found on rocks near the headwaters
Animals are adapted to the cold oxygen-rich waters
Communities and industries affect the health of rivers

11. Section Two: Marine Ecosystems
Coastal Wetlands
Estuaries
Salt Marshes
Mangrove Swamps

12. Section Two: Marine Ecosystems
Estuaries
An area in which fresh water from a river mixes with salt water from the ocean
Serves as a nutrient trap
Mineral rich mud and dissolved nutrients fall to the bottom and become available for producers.

13. Section Two: Marine Ecosystems
Estuaries
Plants and Animals
Manatees, Horseshoe crabs, dolphins, otters, oysters
Able to tolerate variations in salinity
Threats
Used as landfills
Pollutants such as runoff and sewage

14. Section Two: Marine Ecosystems
Salt Marshes
In estuaries where rivers deposit their mineral rich mud
Acts as a nursery for shrimp, crabs, and fish
Absorb pollutants and protect inland areas

15. Section Two: Marine Ecosystems
Mangrove Swamps
Dense growth of mangrove trees in swampy areas
Protect the coastline from erosion

16. Section Two: Marine Ecosystems
Rocky and Sandy Shores
Have more plant and animal species than sandy shores
Barrier islands: run parallel to sandy shores

17. Section Two: Marine Ecosystems
Coral Reefs
Limestone ridges built by tiny coral animals called coral polyps
Found in shallow tropical seas where light is plentiful for photosynthesis
Serve as a habitat for many organisms

18. Section Two: Marine Ecosystems
Coral Reefs
Very fragile
Susceptible to extreme hot or cold and high nutrients
Coral bleaching: when coral turns white and can die
50% of of the world’s coral reefs in danger

19. Section Two: Marine Ecosystems
Oceans
Much of ocean life concentrated in shallow coastal waters
Plants and Animals
Phytoplankton and zooplankton

20. Section Two: Marine Ecosystems
Oceans
Threats
Pollution
Overfishing and certain fishing methods
Arctic and Antarctic
Arctic is rich in nutrients from surrounding land masses
Antarctic is the only continent not colonized by humans