Man and Ocean

The world・s ocean covers about 70% of the Earth・s surface. It is use to produce us many things. It is more than a place to swimming, sailing and other recreation. The ocean serves as a source of energy, raw materials and most of all food like fish and seaweed. In this essay I will talk about "What are our ocean resources and the importance of the oceans in the future."
First, our largest resource in the ocean is food. There are two different kinds of food in the ocean, such as marine plants and marine animals. These two kinds of resources are reborn resources and it will never be end. For marine plants we have the algae\'s family, like seaweed. During ebb tide, you can find the seaweed between rocks. For the marine animals we have fish and shrimp. The fish and shrimp are always moving around the ocean and follow the ocean currents.

What is ocean current? It is a movement of ocean thatcan buring the fish to other places. There are two kinds of circulation create the currents in the ocean. They are (1) wind-driven circulation and (2) Thermohaline circulation. Wind-driven circulation result from the wind sets the surface waters into motion as currents. The currents generally flow horizontally-that is parallel to the earth・s surface. The wind mainly affects only the upper 100 to 200 meters of water. However, the flow of wind-driven currents may extend to depths of 1,000 meters or more.

Thermohaline circulation produces great vertical currents\' hat flow from the surface to the ocean bottom and back. The currents largely result from differences in water temperature and salinity. The currents move sluggishly from the polar regions, along the sea floor, and back to the surface. In the polar regions, The surface waters become colder and saltier. Being colder and saltier makes these waters heavier, and they gradually flow back toward the surface and replace the surface waters that sink. For example, as a warm ocean current and a cold ocean current meet together, The warm water will always follow cold water and moving around the ocean. The most important is the plankton does not like to stay in the cold place. They will follow the warm current. As the result the small fish like shrimp that eats plankton, will follow the plankton. Similarly the bigger fish that eats small fish and shrimp will just follow also and these fishes became a chain.

Our ocean has produced raw material also. Like natural gas and petroleum. These materials are all unaltered. After you have take them out, you need to use machine to take out the dirt. For example the petroleum is use to sucked out by the big pipes. The asphalt road and the clean oil can be the fuel. South china sea has a big processing plant that produces the oil and natural gas. In late 1980・s, offshore wells produced about 25 percent of the world・s oil and about 20 per cent of the world・s gas. Scientists estimate that 3 trillion barrels of oil lie undiscovered beneath the ocean. Equally huge amounts of untapped gas accompany the oil. As gas and oil reserves on land are use up or become too difficult and expensive to obtain, finding and recovering undersea deposits will become increasingly important.

The ocean can be use to produce power. First, we have wave power. Generator was built in the ocean. It has a pumping chamber. It will move up and down to turn the generator. Second, we have tidal power. The generator will have to build on the place were water will falls. The best place is to built it on a dam. Once the dam is full, the water will rush down and it will turn the generator to produce the energy.

Our ocean is very useful, but we are the one that endangers it with pollution. The most common pollution is trash and the chemical waste. People go to sea to fish or to swim they always leave trashes like cans and plastic bag. These things are not easy to dissolve and if we put them together, oh my god can you image? That will be like a small mountain every day.

The next common pollution is the chemical waste (sewage). This pollution is always