1. Freshwater
Chapter 7ish

2. Freshwater Necessary to sustain life for plants and animals!
If you have too much you get:
Floods
Disease
Death
If you have too little you get:
Drought
Starvation

3. Freshwater 70% of the Earth’s surface is water
97% of water is found in oceans
Therefore only 3% is freshwater!
Only 1% is available to use for living things!!!
Out of all the water on earth only 0.01% is fresh surface water (lakes, rivers)!!!!!!!!

4. Chpt 7: Sec 1
Freshwater ecosystems

5. Vocab (Bold label in pic)
Lakes Zones
Picture Outline
Vocab (Bold label in pic)
Wetland
Plankton
Nekton
Benthos
Littoral zone
Benthic zone
Eutrophication

6. Aquatic Ecosystems Organisms determined by salinity
Salinity – amount of dissolved salts in water

7. Organisms Plankton The organisms that float near the surface
Phytoplankton – microscopic plants
Zooplankton – microscopic animals

8. Organisms Nekton Free-swimming organisms Fish, turtles, tadpoles,
large water beetles

9. Organisms Benthos Bottom-dwelling organisms Crabs, clams, decomposers,
Insect larvae

10. Lakes and Ponds
Some bodies of fresh water have areas so deep that there is too little light for photosynthesis.
Bacteria live in the deep areas of freshwater. Fish adapted to cooler, darker water also live there.
Eventually, dead and decaying organisms reach the benthic zone.

11. Lakes and Pond Adaptations
Animals that live in lakes and ponds have adaptations that help them obtain what they need to survive.
For example, water beetles use the hairs under their bodies to trap surface air so that they can breathe during their dives for food.
And, in regions where lakes partially freeze in the winter, amphibians burrow into the littoral mud to avoid freezing temperatures.

12. Littoral Zone Nutrient-rich area near the shore
Life is diverse and abundant. Plants and small animals
Plants:
Cattails
Reeds
Lilies

13. Benthic Zone Region near the bottom
Contains decomposers and insect larvae
Animals:
Clams
Crabs
Barnacles

14. Eutrophication
An increase in the amount of nutrients in an aquatic system.
Eutrophic lake – lake with large amount of plant growth

15. Eutrophication The good: The bad:
Naturally occurs to lakes over a long time
Plants and algae flourish
The bad:
Can be accelerated by human fertilizer or sewage runoff
Bacteria flourish feeding on the decaying plants
They use so much oxygen in the water it kills organisms that depend on oxygen
(Youtube video: ALGAE BLOOM LARGE MOUTH BASS FISH KILL)

16. Fresh Water Wetlands What areas count as wetlands?
Areas of land that are covered with fresh water for at least part of the year

17. Section 1 Freshwater Ecosystems
Chapter 7
Freshwater Wetlands

18. Functions of Wetlands Trapping and filtering water
Keeps sediment, nutrients and pollutants out of lakes, reservoirs and oceans

19. Functions of Wetlands Reduce likelihood of flooding
This protects agriculture, roads, and buildings
Also makes us safer (think if the wetlands could of contained Katrina)

20. Functions of Wetlands
Buffers shorelines against erosion

21. Functions of Wetlands
Provides spawning grounds for fish and habitat for wildlife
Spawning grounds especially commercial fish and shellfish that we eat
Habitat important for a lot of species that migrate

22. Environmental Functions of Wetlands
Section 1 Freshwater Ecosystems
Chapter 7
Environmental Functions of Wetlands

23. Fresh Water Wetlands Two main types:
Marshes – contain non-woody plants
Cattails, reeds, etc.
Swamps – dominated by woody plants
Trees and shrubs

24. Section 1 Freshwater Ecosystems
Chapter 7
Marshes
Freshwater marshes tend to occur on low, flat lands and have little water movement.
In shallow waters, plants root themselves in the rich bottom sediments while their leaves stick out about the surface of the water year-round.
There are several kinds of marshes, each of which is characterized by its salinity. Brackish marshes have slightly salty water, while salt marshes contain saltier water.

25. Section 1 Freshwater Ecosystems
Chapter 7
Marshes
The benthic zones of marshes are nutrient rich and contain plants, numerous types of decomposers, and scavengers.
Water fowl, such as ducks, have flat beaks adapted for sifting through the water for fish and insects. While water birds, such as herons, have spearlike beaks they use to grasp small fish and probe for frogs in the mud.
Marshes also attract migratory birds from temperate and tropical habitats.

26. Section 1 Freshwater Ecosystems
Chapter 7
Swamps
Swamps occur on flat, poorly drained land, often near streams and are dominated by woody shrubs or water loving trees.
Freshwater swamps are the ideal habitat for amphibians because of the continuous moisture. Birds are also attracted to hollow trees near or over the water.
Reptiles are the predators of the swamp, eating almost any organism that crosses their path.

27. 3. Bogs Bogs are wetlands dominated by moss or peat.
Cranberries are often gathered in bogs

28. Human Impact on Wetlands
Section 1 Freshwater Ecosystems
Chapter 7
Human Impact on Wetlands
Wetlands were previously considered to be wastelands that provide breeding grounds for insects.
As a result, many have been drained, filled, and cleared for farms or residential and commercial development.
The importance of wetlands is now recognized, as the law and the federal government protect many wetlands while most states now prohibit the destruction of certain wetlands.

29. Section 1 Freshwater Ecosystems
Chapter 7
Rivers
At its headwaters, a river is usually cold and full of oxygen and runs swiftly through a shallow riverbed.
As a river flows down a mountain, it may broaden, become warmer, wider, slower, and decrease in oxygen.
A river changes with the land and the climate through which it flows.

30. Section 1 Freshwater Ecosystems
Chapter 7
Life in a River
In and near the headwater, mosses anchor themselves to rocks by using rootlike structures called rhizoids. Trout and minnows are adapted to the cold, oxygen rich water.
Farther downstream, plankton can float in the warmer, calmer waters. Plants here can set roots in the river’s rich sediment, and the plant’s leaves vary in shape according to the strength of the river’s current. Fish such as catfish and carp also live in these calmer waters.

31. Rivers in Danger Chapter 7
Section 1 Freshwater Ecosystems
Chapter 7
Rivers in Danger
Industries use river water in manufacturing processes and as receptacles for wastes. In addition, people have used rivers to dispose of their sewage and garbage.
These practices have polluted rivers with toxins, which have killed river organisms and made river fish inedible.
Today, runoff from the land puts pesticides and other poisons into rivers and coats riverbeds with toxic sediments.