ocean: The Ocean as a Biological Environment

The oceans hold the answers to many important questions about the development of the earth and the history of life on earth. For instance, within the rocks and sediment of the ocean floors the geological history of the earth is recorded. Fossils in this sediment record a portion of the biological history of the earth at least back to the Jurassic period, which ended about 140,000,000 years ago. The first appearance of life on the earth is thought to have occurred in the oceans 2 or 3 billion years ago. The modern marine environment is divided into two major realms, the benthic and the pelagic, based upon the ecological characteristics and marine life associated with them. See also marine biology.

Sections in this article:

• Introduction
• Importance of the Ocean
• The Pelagic Realm
• The Benthic Realm
• The Ocean as a Biological Environment
• Thermohaline Circulation
• Surface Circulation
• Relationship of the Ocean and the Atmosphere
• Trenches, Plains, and Ridges
• Continental Shelves, Slopes, and Rises
• The World Ocean
• Bibliography

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