Here is your paragraph on Life Underwater!
The realm below the surface of the water where the water remains in a natural state like in oceans, ponds, lakes etc. form the underwater. Almost three-quarters of the surface of the Earth is covered by water. Humans are engaged in a number of activities conducted underwater like scuba diving, research etc. But however, almost a majority of the underwater still remains unexplored and is expected to have several million undiscovered species of flora and fauna.
Characteristics of Underwater Life:
Man cannot survive underwater because there is too much pressure at that level which makes breathing extremely difficult. The density of water also causes many difficulties at that level. As the underwater depth increases, the visible light starts diminishing. The colour spectrum is speedily altered with increase in depth. In greater depths underwater, the temperature remains very low because of minimal heat energy reaching that level. Sound also travels almost four times faster in that level.
The vast number of plant species underwater forms a beautiful ecosystem. The plants which stay underwater depend upon the light coming from the sun for their growth. They also draw the atmospheric carbon dioxide from the air above and convert them into oxygen. The flora below the surface of the water adds to the aesthetic beauty. These plants sometimes span vast lengths below the surface of the ocean.
The microscopic organisms which remain in the sun-lit areas of the underwater surface are called phytoplankton. They depend upon the minerals for survival. Phytoplankton serves as the basic food of the aquatic animals. Other creatures existing underwater are fish, sharks, whales, sea snakes, jellyfish, smaller aquatic animals etc.
These creatures have built-in gills for breathing and their eyes enable them to look forward as well as sideways. Some of the creatures found underwater are carnivorous in nature and eat other aquatic animals for their survival.
Richness of Underwater Life:
The life underwater is no less rich than the life on the surface of the water or the terrestrial life. The aesthetic beauty of underwater life is one of the prominent features. Coral reefs are splendid examples of the aesthetic beauty of underwater life. These span the length which extends to kilometers at a stretch. The underwater life also provides man with a variety of minerals and other resources for consumption. Terrestrial life has certain disadvantages which are absent in the life underwater.
Life underwater is one of the most exciting things in the world. The same is characterized by plants which exist in a wide variety, aquatic animals which are both dangerous and sober, microscopic organisms which are the basic food of the animals. Even the largest mammal in the world, the blue whale, resides in the oceans. Thus, life underwater is a part of the life on earth.