Section 3: Aquatic Ecosystems Chapter 6: Ecosystems Section 3: Aquatic Ecosystems

1. Rivers and streams – flowing water A. Freshwater ecosystems – include flowing and standing water, low or no salt 1. Rivers and streams – flowing water Hudson River, Bear Mountain Bridge

a. Most nutrients washed into the water from land b. The faster the flow, the greater the oxygen content Grand Canyon, Colorado River

2. Lakes and ponds – very little flow a. Sunlight warms and lights pond bottom, supporting plant and animal life

b. Deeper lakes support life along shallow shoreline or surface

3. Water pollution – a problem caused by fertilizer-filled runoff and sewage

4. Wetlands – regions wet all or most of the year a. Lie between solid land and water Very fertile ecosystems

B. Salt water ecosystems – 95% of Earth’s water contains high concentration of salt, or high salinity

1. Open oceans – divided into lighted and dark life zones lighted – upper 200m and home of plankton

b. dark – below 200m where animals feed on material that floats down or prey on each other Fangtooth fish

Angler fish; polychaete worm

Axolotl fish

blobfish

2. Coral reefs - diverse and fragile ecosystems formed from coral shells of calcium carbonate

Dory blue tang;

3. Seashores – along coastlines Intertidal zone -covered with water at high tide and exposed to air at low tide

b. Drastic changes in temperature, moisture, salinity, and wave action

4. Estuaries - where a river meets an ocean; called bays, lagoons, harbors, inlets, sounds Elkhorn Slough, CA

b. Changing mixture of salt water and freshwater a. Rich in nutrients b. Changing mixture of salt water and freshwater Healthy estuary – Chesapeake Bay (largest estuary in the US)