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OCEANOGRAPHY
Lesson 1 - Page 4

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It is every drop of waterís dream to live at sea level. Water precipitates on land and travels to sea through rivers. The rivers erode the land and chemically dissolves the components of rocks into ions. Over eons of time, most elements become dissolved in seawater. These ions help give the "flavor" to salt water.

Many of these ions can be combined into molecules that are used by living organisms. For example, little critters (protist) like foraminifers require CaCO3 (calcium carbonate) to make skeletons. Radiolaria another protozoa require SiO3 (silica dioxide) to make their skeleton. Other components can be dissolved in marine water while maintaining their own properties. Gases, like oxygen, are very important to help large organisms like fish survive. Small plants on the oceanís surface contribute the majority of oxygen in the water and the atmosphere.

The oceans become the largest holder of water. However, most land animals cannot use salt water directly. The only parts of the oceans that can be used as "fresh" water are icebergs. Only pure water can freeze, leaving behind the salt.


Radiolaria


Sea ice

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