Ocean Vocabulary

Methane Cold Seep

A cold seep (sometimes called a cold vent) is an area of the ocean floor where hydrogen sulfide, methane and other hydrocarbon-rich fluid seepage occurs, often in the form of a brine pool. Cold does not mean that the temperature of the seepage is lower than that of the surrounding sea water.

Photic zone

Photic zone, surface layer of the ocean that receives sunlight. The uppermost 80 m (260 feet) or more of the ocean, which is sufficiently illuminated to permit photosynthesis by phytoplankton and plants, is called the euphotic zone.

Salinity

Salinity is the measure of all the salts dissolved in water. Salinity is usually measured in parts per thousand (ppt or ). The average ocean salinity is 35ppt and the average river water salinity is 0.5ppt or less. This means that in every kilogram (1000 grams) of seawater, 35 grams are salt.

Aphotic zone

The aphotic zone (aphotic from Greek prefix ἀ- + φῶς "without light") is the portion of a lake or ocean where there is little or no sunlight. It is formally defined as the depths beyond which less than 1% of sunlight penetrates.

Intertidal zone

The intertidal zone, also known as the foreshore and seashore and sometimes referred to as the littoral zone, is the area that is above water at low tide and under water at high tide (in other words, the area between tide marks).

Neritic zone

The neritic zone is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately 200 metres (660 ft) in depth.

Open Ocean zone

The oceanic zone begins in the area off shore where the water measures 200 meters (656 feet) deep or deeper. It is the region of open sea beyond the edge of the continental shelf and includes 65% of the ocean's completely open water.

upwelling

a rising of seawater, magma, or other liquid.

Nekton

aquatic animals that are able to swim and move independently of water currents.

Down welling

the downward movement of fluid, especially in the sea, the atmosphere, or deep in the earth.

Benthos

the flora and fauna found on the bottom, or in the bottom sediments, of a sea, lake, or other body of water.

Plankton

the small and microscopic organisms drifting or floating in the sea or fresh water, consisting chiefly of diatoms, protozoans, small crustaceans, and the eggs and larval stages of larger animals. Many animals are adapted to feed on plankton, especially by filtering the water.

Estuary

the tidal mouth of a large river, where the tide meets the stream.