1. AQUATIC ECOSYSTEMS Determined by the salinity of water 2 types:
Freshwater : lakes, ponds, rivers, streams, wetlands
Marine: coastal marshes & swamps, coral reefs, oceans

2. CHARACTERISTICS Determines which organisms live where TEMPERATURE
SUNLIGHT*
OXYGEN
NUTRIENTS
Determines which organisms live where
*Photosynthetic organisms live near the surface

3. Three types of organisms: based on location & adaptations
Plankton
Phytonplankton
zooplankton
Nekton
Benthos

4. Plankton – microscopic drifters
Phytoplankton: photosynthethic
Algae (base of food chain)
Zooplankton: heterotrophic microscopic organisms –
jellyfish

5. Nekton – free-swimming

6. Benthos – bottom dwelling

7. Decomposers

8. 7-1 Freshwater Ecosystems

9. These include rivers, streams, lakes, and ponds.
Rivers and streams have moving water. The water may be moving fast or slow.
Lake are usually larger and deeper than ponds.
Just like in the oceans, plants and animals live in the shallow (less deep) parts. The sun shines more in the shallow parts.

11. Lakes & Ponds Littoral zone: near shore Nutrient rich Diverse life
Plants rooted in mud,
stems above water

12. Littoral zone

13. Lakes & Ponds Open water: Further from shore No rooted plants
Phytoplankton starts food chain

15. Lakes & Ponds Deep Water: No light
Bacteria & decomposers live on dead things that drift down
Fish adapted to cool water

16. Lakes & Ponds
Benthic Zone:
Bottom
Decomposers, insect
larva, clams

19. How nutrients affect lakes
Eutrophication= an increase in the amount of nutrients in an aquatic ecosystem.
Plants & algae grow
Bacteria feeding on decaying plants grow
Bacteria use oxygen in water
Reduced oxygen levels kills fish
Run-off increase nutrients

20. Freshwater Wetlands Swamps – woody plants Marshes – non-woody
Poorly drained land,
Marshes – non-woody
plants (cattails, grasses)

24. Function of Wetlands Trap & filter sediments, nutrients, pollutants
Reduce flooding
Buffer shoreline against erosion
Spawning grounds & habitat for fish & shellfish
Provide habitat for rare, threatened, endangered species
Recreation

25. Human Impact
Considered wasteland & breeders of disease carrying insects. Drained, cleared & developed.
Now we recognize importance as water purifiers & flood prevention.

27. % of Wetlands lost states have lost 50% of wetlands7 have lost 80% (Indiana, Ill, Miss, Ky, Iowa, Calif, Ohio

28. Rivers Headwaters – origin may be snowmelt or rain
Full of oxygen, runs swiftly through shallow riverbed
Becomes wider, warmer, slower, contains more vegetation & less oxygen
Communities & industries affect health of rivers.

30. Flint River

31. Lake Lanier

32. Atlanta’s drinking water

33. Characteristics of Aquatic Ecosystems