Oceans a Source of Energy

The Sea and Climate 

Compared to the sea, land gets heated or cooled very fast. The unequal heating and cooling of land and ocean affects the climate of coastal regions considerably. The regions near oceans do not experience extremes of climate. But in regions which are not close to the ocean, summers are very hot and winters are very cold. The moist winds that blow from the sea during the day moderate the temperature on the land.

 Oceans a Source of Energy

 Energy can be produced from sea waves, tides and ocean currents. Water activated turbines that rotate by the force of waves striking the shore, are installed in the sea near the shore. The waves rotate them and generate electricity. During high tide, when the water level rises, the water is collected in reservoirs. This water is used to rotate the turbines to produce electricity. Tides which have an average height of 5 metres are ideal to produce energy. Power generation is not possible on all sea shores. Why? Oceans are important in one way or another. Do you agree with this statement?

From what you have learnt so far, make inferences.

Marine Pollution

 We have discussed the importance of oceans in human life. When the sea shores became conducive to life, they started to become over populated. This led to uncontrollable interventions both on the sea and shores. Such interventions led to the pollution of the sea and the shore, which has started to pose a threat to the very existence of human beings. Let us see, what the causes of marine pollution are: • Planktons, the primary producers, absorb the chemical effluents reaching the sea as a result of industrialization and urbanization. The toxicity is transferred to the small fish, which consume the planktons and then to the big fish that eat them in turn. This upsets the ecological balance of the sea. • The carbon dioxide, which is considerably increasing at present in the air dissolves in rain forming carbonic acid and reaches the sea increasing the acidity of the ocean water. This also poses a threat to the ecological balance of oceans. • The oil spill because of unlimited overflow of crude oil and diesel from ships is yet another factor causing marine pollution. • As ship voyages increase day by day, the amount of waste disposed from the ships into the ocean is also on the increase. This pollutes harbours and shores beyond tolerable limits. • Thermal and atomic power plants use large quantities of water as coolants. After being used as a coolant in the thermal power plant, the water is let out into the sea or river. This causes the temperature of the sea water to rise. This also significantly upsets the equilibrium of the oceanic environment