FRESHWATER ECOSYSTEMS

RIVERS

• Insects and animals may have hooks, or even suction cups to grasp onto rocks or the ground against tides
• Only a few plants, like algae, can grow here. They grasp onto rocks, or may grow between them.

STREAMS

• Plants root among the pebbles, which provide sustaining food for organisms like insects and sometimes small fish. They may also provide homes for frogs and tadpoles.

LAKES

• Usually larger and deeper than ponds. Sometimes sunlight cannot reach the bottom of lakes, making algae upon the top main producers and food for organisms

PONDS

• Like lakes, though not as commonly, sometimes algae is the top producer. Lots of insects and small organisms live around the shore, and fish feed on the algae.

MARINE ECOSYSTEMS

ESTUARY

• Estuaries are the areas where rivers, containing fresh water, meet oceans, which in turn carry salt water. Usually calm waters, many organisms use this area live.

Intertidal ZONE

• Here, pounding waves, and constant changes in water level and temperature occur. Organisms living here must be able to grasp onto rocks, or be able to put up a fight with the current. Barnacles and sea stars are common.

NERITIC ZONE

• This is a region of shallow water below the low tide. Photosynthesis can occur even underwater here. Lots of organisms inhabit this area as a result, like schools of fish.

SURFACE ZONE

• The first few hundred meters of an ocean is the surface zone. Algae stays in this region to grow, while organisms like tuna, swordfish, and even whales, depend on this algae for food.

DEEP ZONE

• Below the surface zone, is the deep zone. Nearly pitch black here many organisms feed on dead organisms at the bottom. Several animals use adaptations such as odd looks, or luminescent eyes or features to get food or scare away enemies.

ABOUT 75% OF THE WORLD IS OCEAN.