1. KEY CONCEPT Freshwater ecosystems include estuaries as well as flowing and standing water.

2. Estuaries are dynamic environments where rivers flow into the ocean.
An estuary is a partially enclosed body of water.
Large amounts of organic matter (river flow/tides)
mixture of fresh water with salt water (Brackish)
Chesapeake Bay, Florida Bay, Louisiana bayous
Includes salt marshes, mud flats, mangrove forests, tidal pools

3. Estuaries are highly productive ecosystems.
75% of commercial fishing – shrimp, scallops, clams, fish
Estuaries provide a protected refuge for many species.
bird migration
spawning grounds (Nursery of the sea)
Provide buffers for hurricanes (tidal surges)
Estuaries are primarily threatened by land development. 80%

4. Freshwater ecosystems include moving and standing water.
A watershed is a region of land that drains into a body of water.

5. Wetlands are among the most productive ecosystems.
Wetland – area of land that is saturated by ground or surface water for at least part of the year. Ex. Bogs, marsh, swamp
Filters and renews underground water supply
provide a home for many species
filter dirty water

6. Some animals have adaptations suited to the freshwater they inhabit.
Factors that can fluctuate: water temperature, oxygen levels, pH, water flow rate
Fast-moving waters: streamlined fish, sucker mouths

7. Ponds and lakes share common features.
Freshwater bodies are divided into three zones.
Littoral zone - high/low tide
Limnetic zone- (Pelagic) open water
Benthic zone- lake or pond bottom

8. All lakes “turn over” periodically.
Turn over happens due to changes in density. 39o F densest
In both autumn and spring, surface water flows downward and bottom water flows upward.
The upwelling brings up nutrients.