The Forming of the Ocean
The beginning of the ocean could be traced back to the time that earth was born. The earth is about 4.6 billion years old. The earth’s surface temperature cooled down and saturated steam became rainfall that then formed the ancient ocean at 3.9 billion years ago.

Characteristics of the Sea Water
Salinity of the sea water
At the beginning, sea water was acidic rather than salty, and lacked oxygen. As mineral substances in the rock stratums were dissolved and washed out by rain water, and then gathered into the ocean, sea water became salty and bitter. There are plenty of elements in the sea water, including chlorine, sodium, magnesium, sulfur, calcium and potassium etc. Sodium chloride (NaCl) is the major component. The concentration of sodium chloride (NaCl) is about 3.5%. In other words, there are 35g salt in every liter of sea water, and this is the main reason why sea water tastes salty. Sea water in different areas usually has different salinity, depend on latitude and weather condition. In low latitude areas, such as tropical regions, the salinity is higher, as in the high latitude areas, where water was frozen, the salinity is relatively lower.

The Color of the Sea
The color of the sea is related to the wavelength of lights. When light beams illuminate into sea water, lights that have longer wavelengths, such as yellow and red lights were absorbed. Lights that have shorter wavelength, such as the blue light, was scattered by sea water. That makes the ocean look blue. If we examine the sea water more carefully, it’s not merely blue. It is sometimes affected by different solutes in the water that make the water look blackish green or deep blue. For example, waters along the coasts sometimes are greener or redder. This is often a result that planktons or solutes affect the absorbing and scattering of lights. The Kuroshio current passing by the east water area of Taiwan has less planktons and solutes, and most of the light beams were absorbed. Therefore, the sea water at the east coast of Taiwan is deep blue.

Ocean and Climate
Over 70 percent of the Earth's surface is covered by water. The water is not only a cradle of life, but a storage tank of heat. By absorbing and releasing heat at a proper timing, the ocean stabilizes the climate. Besides, the ocean also plays a very important role in carbon dioxide (CO2) regulation by the action of planktons and bacteria that change carbon dioxide (CO2) in the atmosphere to different forms and fixed it in the sea water. Ocean currents also significantly affect the climate. Ocean currents at different latitude transfer heat to different areas, which influence the climate, hydrology and fishery.

Marine resources
When we look at the world map, we can see that almost all large cities are built along the coastal areas. This is because the ocean brings us plentiful resources and mild climates, and nurtured the civilization of mankind. Because of the fact that 70 percent of the Earth's surface is covered by water, all kinds of resources are abundant. Such as marine lives, underwater mining, recreation and tourism industry, and energy resources, are all closely related to the ocean. Since Taiwan is surrounded by the sea, there are plentiful marine resources. It is very easy to explore and use marine resources in Taiwan owing to all large cities are close to the sea.