Earth Science
Life on Earth
Freshwater Ecosystems
Study Tip
Studying diagrams for this topic will help you visualize the different types of freshwater ecosystems.
Freshwater Ecosystems
Freshwater ecosystems contain bodies of water that have almost no salt content. These include lakes and ponds, rivers and streams, reservoirs, wetlands, and groundwater.
Study Tip
Studying diagrams for this topic will help you visualize the different types of freshwater ecosystems.
Lakes
Lakes are divided into three zones:
Zone
Description
Animals
Surface (littoral)
Sloped area closest to the edge of the water
Snails, insects, smaller fish
Open-water (photic/limnetic)
Shallow area of water, receives abundant sunlight
Larger fish such as bass or trout
Deep-water (aphotic/profundal)
Deeper area of water, receives little to no sunlight
Scavengers such as crabs and catfish. Decomposers such as fungi and bacteria
Factors that affect ecosystems in lakes:
- Light
- Pressure
- Temperature
- Vegetation
Wetlands
Certain specialized plants are able to grow in regions of land that holds a great deal of water.
Type
Description
Animals
Marshes
Shallow wetlands that are around lakes, streams, or the ocean. Grasses and reeds are common, but trees are rare.
Frogs, shrimps, turtles
Swamps
A wetland with lush trees and vines, found in low-lying areas beside slow-moving rivers.
Crayfish, alligators, newts
Marsh
Swamp
