1. Aquatic Ecosystems Objectives:
Describe the characteristics of fresh water wetlands.
Define plankton, nekton, and benthos.
Describe human impacts on wetlands.

2. Fresh Water Ecosystems
Only 3% of the Earth’s water is fresh
Organisms living in fresh water are grouped by their location
1.Plankton – drifting microscopic plants and animals (phytoplankton are basis of food chain)

4. Phytoplankton

5. Freshwater Ecosystems
2. Nekton – free-swimming organisms like fish, turtles and whales

6. Freshwater Ecosystems
3. Benthos – bottom-dwelling organisms such as mussels, worms, barnacles

7. Freshwater Ecosystems
Wetland (pg 188)– land that is sometimes covered with fresh water, usually located in the Southeastern US
Marsh – dominated by non-woody plants like cattails
Swamp – dominated by woody plants like trees

8. Freshwater Marsh

9. Freshwater Swamp

10. Wetlands
Trap and filter sediments, nutrients and pollutants, keeping them from entering reservoirs
Reduce the likelihood of flooding
Buffer shorelines against erosion
Provide habitat for commercial important fish and shellfish
Provide habitat for rare and threatened species
Provide recreation

11. Wetlands Human Impacts pg 206 pg 207
Residential and Commercial Development
6 million acres of the Everglades in South Florida were drained and filled for building
pg 206
pg 207

12. Pond or Lake

13. Pond or Lake
Littoral Zone – shallow water closest to shore, photosynthesis happens here
Limnetic Zone – layer of open water, nekton swim here, photosynthesis happens here
Profundal Zone – deeper, cold, dark water where light does not penetrate, nekton swim here
Benthic Zone – bottom, deep, cold, dark ground where decomposers are

14. Pond or Lake Human Impacts
Eutrophication – an increase in the amount of nutrients (phosphates and nitrates) in an aquatic ecosystem caused by sewage, fertilizers or animal waste
Causes an excessive amount of algal growth and decay (algal bloom)
The algal bloom can produce toxins that kill animals
Causes a decreased level of oxygen which kills animals

15. Eutrophication

16. Eutrophication - Prevention and Reversal
Oyster reefs filter out extra nutrients
Laws regulating the discharge of sewage
Educating farmers on fertilizer use

17. Eutrophication
Your town is planning to build a golf course. Golf courses use fertilizer and pesticides to keep the grass green and healthy. The city also intends to create lakes around the golf course. The lakes will be stocked with fish. The town hopes that fishermen will pay for fishing licenses and that this revenue will help the town pay for the sports programs at the high school.
Write a 10 sentence letter (minimum 75 words) to the city council describing your opinion on this plan. Use what you know about eutrophication to support your opinion. In addition, suggest a different idea that will fund the school’s sports program. Be prepared to read your letter out loud.