Freshwater Ecosystems * Prepare yourself, there are 35 slides!
Jan 02, 2016
Freshwater Ecosystems
* Prepare yourself, there are 35 slides!
Freshwater Ecosystems
• Only covers 3% of Earth’s surface
• What makes them different?
Abiotic Factors• Water Speed / flow
• Depth
• Temperature
• Chemistry (salinity)
Organisms
• Grouped by location & adaptations
• 3 groups
1 - Plankton• Float near the surface
• Phytoplankton – single celled algae; produce most of the food for an aquatic ecosystem
• Zooplankton – microscopic animals
2 - Nekton
• Free swimming
• Ex. fish & turtles
3 - Benthos
• Bottom dwelling
• Most live attached to hard surfaces
• Ex. mussels, worms & barnacles
Lakes – 5 Types!
• 1- Glacial lake: formed by depressions in the surface
• 2- Barrier lakes: formed from landslides
• 3- Crater lakes: volcanoes
• 4- Tectonic lakes: formed from rift valleys
• 5- Artificial lakes: humans (dams) & beavers
Ponds
Zones
Littoral Zone• Shore
• Nutrient rich
• Diverse & abundant life
Benthic Zone• No light
• Decomposers, insect larvae & clams
Animal Adaptations
• Water beetles – hair to trap air
• Catfish – whiskers to sense
• Amphibians – burrow in the cold
Eutrophication
• Increase in the amount of plant growth due to nutrients
• ↑algae = ↑bacteria = ↓oxygen
• Occurs naturally over long time
• Accelerated by run-off
Wetlands• Covered with fresh water for part
of year
• Traps & filters pollutants (keeping them out of cycle)
• Reduces chances of flood
• Prevents erosion
• Provides spawning ground & habitats
• Provides recreational areas
• 2 types
Marsh• Treeless
• Low, flat lands
• Characterized by salinity
• Brackish Marsh – slight NaCl
• Salt Marsh – more NaCl
Swamp• Has Trees
• Flat, poorly drained land
• Near streams
• Mangrove – near ocean
Human Impact on the Wetlands
• Drained, filled, cleared
• Farms, residential & commercial development
• Florida Everglades – from 8 million to 2 million acres
Stream
Rivers
Rivers
• Many originate from snow capped mountains
• Flows, broadens to become slower, warmer & wider
• Mosses anchor in the flow
River problems• Industrial pollution
• Kills organisms
• Makes fish inedible
• Carries pollution in the run-off
• Dams alter ecosystems
Brainpop: Rivers