33 terms

Georgia Virtual Learning: Marine Oceanography Terms

Pelagic zone
The open ocean, also referred to as the water column
Neritic zone
The shallow area of the ocean that extends above the continental shelf and extends along the coastline of major land masses of the world.
Intertidal zone
Also known as the foreshore, it is the area that is exposed at low tide and submerged at high tide.
Oceanic zone
Extends from 200 meters down to the bottom of the ocean.
Benthic zone
The ocean zone found at the deepest parts of the ocean.
Euphotic zone
The layer nearest the surface of the ocean. It is also referred to as the sunlit zone. Free floating photosynthetic organisms live in this zone and provide the basis for the food chain. Because of their presence, more than 90 percent of all marine life lives here.
Disphotic zone
Only a small amount of light can penetrate the water at this depth. As the water becomes deeper, the pressure increases. Only animals that have adapted to little light survive. The disphotic zone is also known as the twilight zone. This murky part of the ocean begins at about 600 feet under the water and extends to the darkest part, which begins about 3000 feet down.
Aphotic zone
Ninety percent of the ocean is in the midnight zone. It is entirely dark—there is no light. The water pressure is extreme and the temperatures are near freezing. The aphotic zone is also called the midnight zone. The living things found here live close to cracks in the Earth's crust. These cracks give off mineral-rich materials from the Earth itself. Special forms of bacteria utilize hydrogen sulfide from the cracks for energy to make food. All other living things in the midnight zone are nourished by these bacteria.
Any floating or feebly swimming organisms that live close to the surface of the ocean. Phytoplankton are plankton that are autotrophic and can produce their own food; whereas zooplankton are plankton that rely on other organisms for food.
Strong swimming organisms that live in open water. Nektonic creatures, however, begin their lives as plankton. Most of the nekton are vertebrates such as fish, marine mammals, and marine reptiles. Squid are the only invertebrates that are strong enough to be considered nekton.
Organisms that live on, in, or near the ocean floor. The term benthos means "depths of the sea" but this does not necessarily mean these organisms must live deep within the ocean. Examples of benthic organisms include polychaete worms, coral, seaweed, copepods, crabs, and bivalves.
Organisms capable of making their own food using energy from the sun
Organisms that cannot make their own food and must rely on producers for food.
Most commonly first level consumer organisms that eat only plants.
Organisms that eat plants and other animals
Most commonly third level consumers that eat other animals
Organisms that feed on dead organisms
Heterotrophic or detritivorous microscopic invertebrate animals that drift in the water.
Microscopic autotrophic organisms that drift in the ocean
Organisms that recycle dead plants and animals into chemical nutrients
Relating to, produced, or caused by living organisms within an environment.
Non-living chemical and psychical factors in the environment.
Limiting factors
The availability of food, water, shelter, and space which influences plants and animal populations.
The variation of lifeforms within a given ecosystem, biome, or the entire earth
Interactions between two or more organisms, or group of organisms that use a common resource in short supply.
A biological interaction where a predator feeds on another organism
A form of predation in which an organism consumes autotrophic organisms.
An ecological or environmental area that is inhabited by a particular species
A relational position of an organism's species.
A biological interaction between individuals of two different species where both individuals benefit
A symbiotic relationship between two organisms of different species in which one benefits and the other is unaffected
A symbiotic relationship between two organisms of different species where one organism benefits and the other is harmed.
Ozone layer
A layer in the earth's stratosphere at an altitude of about 6.2 miles (10 km) containing a high concentration of ozone, which absorbs most of the ultraviolet radiation reaching the earth from the sun.