1. Marine Ecosystems
Biology

2. The Divisions of the Ocean
The ocean can separate the shore, littoral zone, from the open, or pelagic zone, from the ocean floor, benthic zone.
The presence, photic zone, or absence, aphotic zone, of light also differentiates between areas of the ocean.

3. The ocean is also separated into zones based on its distance from the shoreline and water depths.
Intertidal zone – strip of land between the high and low tide lines
Neritic zone – from the intertidal zone out to the edge of the continental shelf.
Bathyal zone – from the edge of the neritic zone to the base of the continental shelf.
Abyssal zone – lies below 2000 meters and is in incomplete darkness.

4. Intertidal
Neritic

6. Life in the Neritic Zone
Most of the biomass in this zone in plankton, tiny free floating organisms that live in the water.
Zooplankton is another terms for animal plankton and phytoplankton are photosynthetic plankton.

7. Coastal Waters Coral reefs are found in tropical climate zones.
Corals are animals that have a mutualistic relationship with algae.
Corals are very delicate and are in decline around the world.
In contrast to corals, kelp forests live in cold waters and consist of kelp, or seaweed.

8. The point where a river flows into an ocean is called an estuary.
The distinctive feature of an estuary is the mixture of fresh and salt water.
This area is nutrient rich and are very productive environments. They also provide habitats for a number of endangered and threatened species.

9. A watershed is the region of land that drains into a river or another body of water.
Its important to know that water can be standing (wetland, swamps and lakes) or moving (rivers, streams, oceans).