Marine Biology

marine biology, study of ocean plants and animals and their ecological relationships. Marine organisms may be classified (according to their mode of life) as nektonic, planktonic, or benthic. Nektonic animals are those that swim and migrate freely, e.g., adult fishes, whales, and squid. Planktonic organisms, usually very small or microscopic, have little or no power of locomotion and merely drift or float in the water. Benthic organisms live on the sea bottom and include sessile forms (e.g., sponges, oysters, and corals), creeping organisms (e.g., crabs and snails), and burrowing animals (e.g., many clams and worms). Seafloor areas called hydrothermal vents, with giant tube worms and many other unusual life forms, have been intensively studied by marine biologists in recent years.

The distribution of marine organisms depends on the chemical and physical properties of seawater (temperature, salinity, and dissolved nutrients), on ocean currents (which carry oxygen to subsurface waters and disperse nutrients, wastes, spores, eggs, larvae, and plankton), and on penetration of light. Photosynthetic organisms (plants, algae, and cyanobacteria), the primary sources of food, exist only in the photic, or euphotic, zone (to a depth of about 300 ft/90 m), where light is sufficient for photosynthesis. Since only about 2% of the ocean floor lies in the photic zone, photosynthetic organisms in the benthos are far less abundant than photosynthetic plankton (phytoplankton), which is distributed near the surface oceanwide. Very abundant phytoplankton include the diatoms and dinoflagellates (see Dinoflagellata). Heterotrophic plankton (zooplankton) include such protozoans as the foraminiferans; they are found at all depths but are more numerous near the surface. Bacteria are abundant in upper waters and in bottom deposits.

The scientific study of marine biology dates from the early 19th cent. and now includes laboratory study of organisms for their usefulness to humans and the effects of human activity on marine environments. Important marine biological laboratories include those at Naples, Italy; at Plymouth and Millport in England; and at Woods Hole, Mass., La Jolla, Calif., and Coral Gables, Fla. Research has been furthered by unmanned and manned craft, such as the submersibleAlvin.

See also oceanography.

See R. Carson, The Sea Around Us (rev. ed. 1961); R. Ballard, Exploring Our Living Planet (1983); M. Banks, Ocean Wildlife (1989); W. J. Broad, The Universe Below (1997).

The Columbia Encyclopedia, 6th ed. Copyright© 2014, The Columbia University Press.

Marine Biology: Selected full-text books and articles

Coastal and Submarine Morphology
André Guilcher; B. W. Sparks; R. H. W. Kneese.
Methuen, 1958
Living Resources of the Sea: Opportunities for Research and Expansion
Lionel A. Walford.
Ronald Press, 1958
East African Ecosystems and Their Conservation
T. R. McClanahan; T. P. Young.
Oxford University Press, 1996
Librarian’s tip: Section II "Marine Ecosystem"
The Sea off Southern California: A Modern Habitat of Petroleum
K. O. Emery.
Wiley, 1960
The Biology of Rocky Shores
Colin Little; J. A. Kitching.
Oxford University Press, 1996
Zoogeography of the Sea
Sven Ekman; Elizabeth Palmer.
Sidgwick & Jackson, 1953
Field Book of Seashore Life
Roy Waldo Miner.
Putnam, 1950
Beneath Tropic Seas: A Record of Diving among the Coral Reefs of Haiti
William Beebe.
G.P. Putnam's Sons, 1928
Exceptional Fossil Preservation: A Unique View on the Evolution of Marine Life
David J. Bottjer; Walter Etter; James W. Hagadorn; Carol M. Tang.
Columbia University Press, 2002
Marine Ecology
Hilary B. Moore.
John Wiley & Sons, 1958
Hierarchical Perspectives on Marine Complexities: Searching for Systems in the Gulf of Maine
Spencer Apollonio.
Columbia University Press, 2002
The Open Sea, Its Natural History
Alister C. Hardy.
Houghton Mifflin, 1956
Looking for a topic idea? Use Questia's Topic Generator