Page 29 - Science Course 3 (Book 1)

Mo1-L3a: What are the Types of Freshwater?

Soil that washes into a river from streams introduces Freshwater: Ponds and Lakes
nutrients such as nitrogen and can make river water
muddy Bodies of water like ponds and lakes form in low
areas on land and contain freshwater that is not
flowing downhill.
Sunlight reaches the bottom of most ponds.

Slow-moving river
water has higher levels
of nutrients and lower
levels of dissolved
oxygen than fast-
moving water.

Lakes are larger and deeper than ponds and sunlight
Willows, cottonwoods, and other water-loving plants only penetrates the top few feet of water.
grow along streams and on riverbanks.

Plants surround ponds and lake shores and surface
Dams from hydroelectric plants stop the water’s flow. water contains plants and algae.
Runoff from cities, industries, and farms is a source
of pollution. Organisms like insects, frogs, fish, and turtles live in
shallow water near shorelines, but few organisms
live in the deeper, colder water of lakes.

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