Intertidal (Splash) Zone This region is the most changeable in the ocean. Anemones, crabs, clams, mussels and plants such as seaweed live here. They must be able to exist without water for periods of time. They must be able to anchor to keep from being washed out to sea.

Estuary An environment along the oceans edge Is a coastal inlet or bay where fresh water from a river mixes with salty ocean water. Water is known as brackish.

Neritic ( Shelf) Zone This zone extends to a depth of 200 meters and receives plenty of sunlight. The water pressure is low and the temperature is constant. This zone can support plankton, nekton and benthos. Marine life is most abundant here.

Coral Reefs Can form only in shallow tropical ocean waters Produce a hard material around their soft bodies When they die, the hard material is left behind

Kelp Forests Grow in cold neritic waters where the ocean has a rocky floor

Open Ocean Zones There are two open-ocean zones: Bathyal & Abyssal

Bathyal (Slope) The bathyal zone begins at the continental slope and extends down about 2000 meters. Sunlight cannot penetrate the bottom of this zone and plants do not grow at the bottom. Many forms of nekton, such as squid, octopus and large whales live in this zone.

Abyssal (Ocean Floor) Zone At a depth of about 2000 meters, the abyssal zone begins. The abyssal zone extends to a depth of 6000 meters. This zone covers the large flat plains of the ocean. No sunlight can penetrate and food is scarce. The water pressure is great. Most of the animals here are small. Many deep sea fishes produce their own light called bioluminescence.