1. Freshwater Ecosystems Lakes, Rivers and Streams
Aquatic Ecosystems
Freshwater Ecosystems
Lakes, Rivers and Streams

2. Objectives
Be able to describe the factors that determine where an organism lives in an aquatic ecosystem
Be able to describe the littoral zone and benthic zone that make up a lake or pond
Be able to describe 2 environmental functions of wetlands
Be able to describe one threat against river ecosystems

3. Aquatic Ecosystems
The types of organisms that live in an aquatic ecosystem is determined by the water’s salinity
Salinity is the amount of dissolved salts the water contains.
Freshwater= <0.5 ppt
Saltwater= ppt
Aquatic Ecosystems are divided into Freshwater and Saltwater or Marine

4. Freshwater vs Saltwater
Lakes and Ponds-Slow
Rivers and Streams-Fast
Wetlands-water logged land
Marshes and Swamps
Saltwater or Marine
Marshes and Swamps-Coastal
Coral Reefs
Deep Oceans

5. Characteristics of Aquatic Ecosystems
Aquatic Ecosystems are characterized by
Temperature
Sunlight Depth
Oxygen Concentration
Available Nutrients
Aquatic Organisms are grouped by their location at water depths and adaptations
Plankton-Surface, provide most of food, producers
Zooplankton-microscopic animals
Phytoplankton-microscopic plants
Nekton-Free swimming organisms
Fish, Turtles, Whales
Benthos-Bottom dwelling organism, lived attached to hard surfaces
Mussles, worms and Barnacles

6. Lakes and Ponds
Form naturally where ground water reaches the Earth’s surface
Humans and animals like beavers create lakes and ponds by interrupting water flow
Lake structure-2 zones
Littoral Zone-Surface, Sunlight
Aquatic Plants and Animal
Benthic Zone-Bottom, Dark
Bacteria, Decomposers, Bottom Feeding Fish
Animal Adaptations-Whiskers on Catfish to find food on the bottom, Amphibians burrow into the mud in winter to avoid freezing

7. Nutrients in Lakes
Lakes with an abundant amount of nutrients, causing overgrowth of plants, algae and bacteria are known as Eutrophic Lakes
Depletion of oxygen in these lakes called Eutrophication-kills off oxygen requiring organisms
Rainwater runoff carrying sewage, fertilizers and animal wastes from land into the water accelerates Eutrophication

8. Wetlands Areas of land covered by water for part of the year
2 Types of Wetlands
Marshes-contain nonwoody plants such as cattails, low, flat lands, characterized by salinity-ex. Florida Everglades
Swamps-dominated by woody plants such as cypress trees, low, poorly drained land, good habitat for amphibians- ex. Louisiana bayou
2 Purposes of Wetlands
Filter and absorb water-prevents pollutants from entering ground water
Control Flooding-absorb river overflow
Homes and nesting area for migratory birds
Cranberry, crawfish production
Wetlands are protected in many states

9. Rivers
Originate from snow melt in the mountains of Minnesota 1475 ft above sea level
2320 miles long, flows southward in meanders, terminating 95 miles below New Orleans at sea level or O ft.
4th longest river in the world
Changes with the land and climate through which it travels
Higher altitudes-cold, narrow, fast, oxygen rich-Head Waters
Trout, Minnows, Moss
Lower altitudes-warmer, wider, slower and decreased dissolved oxygen-Ends in a fan shape called the Delta
Plankton, Carp, Catfish
Arrowhead, Crowfoot

10. Threats to River Systems
Industries use river water in manufacturing processes and release waste into the waters.
People dispose of sewage and garbage in rivers
Pollutants and toxins produced have killed river organisms and made river fish inedible
Water runoff from land carries pesticides, fertilizers and manufacturing chemicals into the river coating sediment with toxic waste
Pollutants enter ground water and human drinking water resources in rural areas.

11. What Do You Know?-60 points
1.Why are aquatic ecosystems divided into freshwater and saltwater?
2. Freshwater ecosystems include what 7 bodies of water?
3. Summarize the 4 factors that characterize where organisms live in aquatic ecosystems?
4. Compare the littoral zone and benthic zone of lakes.
5. Describe 2 environmental functions of wetlands.
Trace the path of the Mississippi river, where does it start and end?
6. Discuss the importance of one threat against river ecosystems
Answer the questions and complete the tasks above.
All of the answers can be found in the PowerPoint presentation
Write the questions.
Answer each question using complete sentences.

12. Black History Month Extra Credit 110 points
Who founded the first settlement of Chicago?
When was this person born?
Where was he born?
Who were his parents?
Who did he marry?
What were the names of his children?
Name the river upon which the settlement was founded.
What was his occupation?
When did he die?
Where is he buried?
What Chicago Public School and Museum is named after this person?