1 minute read

Ocean Zones

Recent Discoveries



As oceanographers extend their studies to the deepest parts of the oceans, they continually encounter surprises in the kinds of marine life found there. One of the most interesting of these surprises was the discovery of deep sea vents found near the Galapagos Islands in 1977. These vents are located in regions where molten rock lies just below the surface of the seafloor, producing underwater hot springs. Volcanic "chimneys" form when the escaping super-heated water deposits dissolved minerals and gases upon coming in contact with the cold ocean water. The vents are surrounded by intriguing communities of organisms never seen before the 1977 discovery.



The basis for these non-photosynthesis based communities are bacteria that obtain energy from the oxidation of hydrogen sulfide escaping from the vents—a process called chemosynthesis. These bacteria (primary producers) are then used as foods by tube worms, huge clams, and mussels, and other organisms (primary consumers) living around the vents. These communities live in total isolation from photosynthetic-based communities (all other biological communities are photosynthesis based), and may provide clues to the nature of early life on Earth. Later studies have shown that hydrothermal vent communities exist in other parts of the ocean depths as well.

Resources

Books

Ellis, Richard. Encyclopedia of the Sea. New York: Knopf, 2000.

Golden, Fred, Stephen Hart, Gina Maranto, and Bryce Walker. How Things Work: Oceans. Alexandria, VA: Time-Life Books, 1991.


David E. Newton

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Benthic

—Pertaining to the ocean floor.

Chemosynthesis

—The chemical process by which bacteria, by oxidizing hydrogen sulfide, serve as primary producer for a marine community.

Consumer

—An organism that consumes other organisms as a food source.

Littoral

—The part of the benthic realm between high and low water points.

Pelagic

—The water portion of the ocean, usually divided into the neritic and oceanic divisions.

Phytoplankton

—Microscopic aquatic plants.

Producer

—An organism that is capable of utilizing non-living materials and an external energy source to produce organic molecules (for example, carbohydrates), which are then used as food.

Zooplankton

—Minute animal life that lives in water.

Additional topics

Science EncyclopediaScience & Philosophy: Nicotinamide adenine dinucleotide phosphate (NADP) to Ockham's razorOcean Zones - Water Depth Vs. Light Penetration, The Benthic Realm, Epipelagic Zone, Mesopelagic Zone, Bathypelagic, Abyssopelagic, And Hadalpelagic Zones - The pelagic realm