THREE QUARTERS OF THE EARTH is covered by the beautiful sea.
The earth being the only planet in solar system with water in much more appreciable quantity covering seven –tenths of the surface of this globe.
This boon from God bestowed upon the mankind need to be preserved to balance the Nature to sustain life itself.
For million of years The sea offerred open adventure and the explorers across the globe tore down the stormy seas to lay bare the secrets of life underneath,and along the coastal waters fringing the different continents.
The coastal seas
Coastal seas lie over the Continental shelves.
The Continental shelves, 45 miles wide stretches over the western coasts of North and South America to around 900 miles of the Arctic coast of Siberia.
At outer edge the sea is 450 ft deep and the continental shelves slope down to the depth of 20,000ft.
Glaciers have been useful natural bulldozer in moulding the Continental shelves by planning down the land around the coasts .The process is still on in the glacial coasts of Antartica.
Continental shelves are made of recently deposited deep layers of sediments turned to rock.
Four kinds of Continental shelves are as follows.
Fault Dam is made by volcanic or earth quake activity. The slope of the shelf floor is very steep.
Reef Dam consists of Algae or coral growths or even living coral — north- eastern Australia continent.
When there is caused by upward movement of salt bed – the west Coast of the Gulf of Mexico.
No Dam is caused when no barrier holds back the sediments, the shelf slopes downwards as along the coast of Europe.
The Rivers of the world carry 750 million tons of sediments into the coastal waters every year.
The minerals present in the sediment, like phosphates, nitrates, calcium and silica are essential for life to plants in the sea as on the land.
The Natural cycle of life and death
Whales and Fishes
Every animal of the ocean eats and is eaten in the natural cycle of life and death as on land.
The fate is same for even for the big whales as well. The whales when die, their bodies are broken down by living inmates and the nutrients released into the oceans form endless food reservoirs.
The plants like Diatoms, dinoflagellates, enrich the sea life by converting inorganic substances into the food through photosynthesis.
The most abundant animals in the sea, the copepods, and other minute creatures convert some of the sea plants into flesh ,which is eaten by bigger animals size ranging from Herring to blue whales.
Blue whales in attacking mood
The number of animals decrease as the big carnivores, whales,, giant squid and large fish, white sharks dominate the animal spectrum.Some creatures such as sponges, mussels and sea squirts feed by filtering food particles from enormous amounts of water.Other ones burrow down the bottom eating from the embedded particles.
Brightly coloured Sea anemones hide in the bottom mud keeping mouth and tentacles visible to prey upon creature.
Crabs and lobsters move across the ocean floor to pounce upon anything they can with their princers.
A star fish entangles a mussel with its blue tube feet and when the shell open it inserts its stomach to digest the victim.
The battle of survival continues and the life moves on in the great simmering seas forever unabated.