I. Freshwater Ecosystems
a. Inc. rivers, streams, lakes, ponds & wetlands
b. Aquatic Organisms
i. 3 types depending on location
1. PLANKTON
a. Org. that float near surface
i. PHYTOPLANKTON
1. Microscopic plants
2. Main food source for aquatic org.
ii. ZOOPLANKTON
1. Microscopic animals
2. NEKTON
a. Free swimming org.
b. Fish, turtles, frogs, etc.
3. BENTHOS
a. Bottom dwelling org.
b. Muscles, worms, crawfish,etc
c. Decomposers usually found here
c. Lakes & Ponds
i. Structured into horizontal & vertical zones
1. LITTORAL ZONE
a. Found near shore
b. Nutrient-rich soils
c. Sunlight reaches all the way to bottom
i. High photosynthesis of plants
d. High biodiversity
2. BENTHIC ZONE
a. Bottom of pond/lake
b. Sunlight does not reach to bottom
c. Low biodiversity
ii. EUTROPHICATION
1. Increase in amt of nutrients in aquatic system
2. Leads to large plant growth
a. Inc. in algae, floating plants, ect
3. Accelerated by fertilizer run-off
4. As plants die, bacteria feeds, using oxygen
a. More plants = more bacteria = less O2 = less animal life
d. Wetlands
i. WETLAND = Land covered w/water at least part of the year
ii. 3 Main Types
1. MARSH
a. Non-woody plants such as grasses & cattails
b. Can be freshwater, brackish (semi-salty), or salt
c. Florida Everglades, many along coast of Great Lakes
2. SWAMP
a. Woody plants such as trees & shrubs
b. Land usually poorly drained
c. Freshwater or Mangrove (salty)
d. Many in Northern Michigan
3. BOG
a. Poorly drained wetland covered in mosses & shrubs
b. Very poor oxygen & acidic water
i. Very few microorganisms & water living animals
iii. Wetland Functions
1. Natural Filters
a. Absorbs & removes toxins from water through soil & plants
2. Controls Flooding
a. Helps hold & absorb extra water
3. Wildlife feeding & spawning
4. Migratory stop over
iv. Wetland Misconceptions
1. Once thought to be breeding ground for harmful insects
a. Humans drained or filled in millions of acres of wetlands
b. Everglades once covered 8million acres, today less than 2million
2. Laws now protect wetlands
a. MICHIGAN WETLAND MITIGATION
i. Those wishing to develop on protected wetlands must agree to restore or create new wetlands that are 2x-5x the size of the wetland destroyed.