Marine Environments

The place or home in which an organism lives is called its habitat. The total surroundings are its environment.

All environments are affected by biotic and abiotic factors. Living things * PLANTS * ANIMALS * BACTERIA

Abiotic factors - Nonliving things * SALINITY * TEMPERATURE * PRESSURE * LIGHT

The marine world contains many life zones. Life zones are regions that contain characteristic organisms that interact with one another.

Marine life zones * SUPRATIDAL * INTERTIDAL * SUBTIDAL * PELAGIC Many organisms have adaptations that allow them to survive in different zones.

The supratidal zone is the area just above the tide line, or above the intertidal zone. The lower supratidal zone, closer to the water, has little or no life because it is too salty. The upper supratidal zone is home to many species of grasses, shrubs and trees.

The intertidal zone is, like its name suggests, the area between high and low tide. It is the region that is underwater at high tide but not during low tide.

High tide is marked by the strandline a long line of seaweed and debris.

Characteristic organisms of the intertidal zone include: * Beach fleas * Crustaceans * Mollusks * Worms These organisms are adapted to living where it’s sometimes wet and sometimes dry

The subtidal zone is the area below the tide line. It is an area of heavy wave impact and underwater turbulence.

Many organisms that live in the subtidal zone have adaptations that allow them to survive there such as: * Clinging structures * Flat bodies

Characteristic organisms of the subtidal zone are: * Sponges * Clams * Sea stars * Crabs * Mussels * Shrimp * Barnacles * Snails * Flatfish (flounder)

The Pelagic zone is the largest life zone and covers the whole rest of the ocean. It is divided into two other zones: * Neritic zone * Oceanic zone

The neritic zone lies after the subtidal zone and above the continental shelf.

Most deep sea and commercial fishing is done in the neritic zone. The neritic zone contains many species of fish that are supported by algae phytoplankton and marine plants.

The oceanic zone is the area known as the open ocean. The oceanic zone is divided into two zones based on how deep the sunlight penetrates.

The photic zone is the upper area where the sunlight reaches. It is, at most, about 200 meters (600 feet) deep. The aphotic zone is the region below, where the sunlight does not reach.

Most organisms live in the photic zone. Some organisms do live in the deep waters of the aphotic zone. Those that do have special adaptations that allow them to live in the dark.

The Benthic zone includes the entire ocean floor from the intertidal zone to the oceanic zone.

The deepest part of the ocean floor is called the ocean basin.