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India's islands, atolls and coral fauna -bharat ke dvep, pravaal dvep evan pravaal jeev

India's islands, atolls and coral fauna -bharat ke dvep, pravaal dvep evan pravaal jeev


India's islands, atolls and coral fauna -bharat ke dvep, pravaal dvep evan pravaal jeev
श्रेय : NASA Johnson Space Center
लाइसेंस: Public domain

islands of india

  • Himalaya is a newly folded mountain.  It turns south through the northeastern states of India, the Himalayas known as Arakanyoma in Myanmar.
  • The raised top part of the Arakanyoma Mountains in the Bay of Bengal looks like an island, thus it can be said that the Andaman and Nicobar Islands located in the Bay of Bengal are the extension of the Himalaya Mountains (Arakanyoma) in the Bay of Bengal.  is |
  • Under the Indian subcontinent, a total of 222 islands are included in the Bay of Bengal, the Bay of Mannar and the Arabian Sea, in which about 204 islands are located only in the Bay of Bengal and the rest in the Gulf of Mannar and the Arabian Sea.
  • The two major union territories of India, Andaman and Nicobar Islands and Lakshadweep are a group of islands.  The Andaman and Nicobar Islands are the southern part of the Arakanyoma Mountains.  These islands are spread in the form of a narrow chain from north to south direction.
  • Andaman and Nicobar Islands are located between 6º39′ North latitude and 13º34′ North latitudes, its total area is about 8249 square kilometers.

Andaman and Nicobar Islands consist of 4 main islands-
  1. North Andaman Islands - North Andaman Island is the northernmost point of Andaman, its highest peak is Saddle Peak, whose height is 738 meters.
  2. Middle Andaman Islands – Middle Andaman is the largest island of the Andaman Islands.
  3. South Andaman Islands - Port Blair, the capital of Andaman and Nicobar Islands, is located on the South Andaman Islands.
  4. Little Andaman Island - The northernmost island of the Andaman Islands is North Andaman Island and the southernmost island is Little Andaman Island.  An extension of 100  channel is found in the south of Little Andaman.
  • Saddle Peak is the highest peak of the Andaman Islands.  Saddle Peak (732 m) is located on North Andaman Island near Diglipur.  Another island located in the north of the Andaman Islands is Coco Island, which is under the control of Myanmar.
  • Andaman and Nicobar Islands are located in the Bay of Bengal, but between these two islands, a narrow sea is visible, which is called 100  Channel.
  • The Car Nicobar Islands are located to the south of 100 Channel.
  • Indira Point, the southernmost point of India, is located on the Great Nicobar Island, Indira Point is also called 'Pygmalion'.
  • The highest peak of the Nicobar Islands, Mount Thulier (642 m) is located on the Great Nicobar Island.
  • Narcondam Island is a dormant volcanic island.  Dormant volcano means that there was an eruption of volcano here earlier, but now there has not been an event of volcanic eruption here for a long time.
  • Barren Island is an active volcanic island, that is, volcanic eruptions take place here from time to time.
  • Before the Ganges enters Bangladesh, a stream of it turns south in West Bengal, which is known as the Hooghly River.
  • There are two islands named Gangasagar and New Moor on the banks of river Hooghly.
  • Kolkata is a port, but it is located on the banks of the Hooghly River, not on the sea coast.
  • The Brahmani river flows in the state of Orissa, Wheeler Island is situated at the mouth of this river.
  • Sriharikota Island is located off the coast of Andhra Pradesh, here is the launching pad of the Indian Space Research Institute, also known as the Satish Dhawan Space Center.
  • Sriharikota Island on the eastern coast of India separates Andhra Pradesh from Pulicat Lake.
  • Pamban Island is situated off the coast of Tamil Nadu state, Pamban Island is situated in the Gulf of Mannar between Tamil Nadu and Sri Lanka.
  • Rameshwaram is on the Pamban island itself, the easternmost part of this island is called Dhanushkodi.  Ram Sethu starts from here, which goes till Thalaimannar in Sri Lanka.  Thus Dhanushkodi, Pamban, Rameswaram and Ramsethu are all situated in the Gulf of Mannar.
  • Aliyabet Island is situated at the mouth of river Narmada in the Gulf of Khambhat, here there is abundant storage of petroleum, but its exploitation has not yet started.
  • An island is located near Mumbai, the capital of Maharashtra, which is called Elephanta Island.
  • Mumbai is located on the main part of India, but it is further out from the main part towards the sea, due to which it looks like an island, its name is Salsit Island.  Thus it can be said that Mumbai is situated on Salsit Island.
  • Lakshadweep is the smallest union territory of India, made up of coral, whose capital is Kavaratti.  It is spread over an area of ​​about 32 square kilometers between 8º North latitude and 11º North latitude.

भारत में द्वीपों की स्थिति

प्रवाल जीव

coral fauna

  • Corals grow in shallow seas and continental shelf.  Coral creatures are not found in deep water.
  • The origin of corals occurs in tropical seas between 30º north and 30º south latitude.
  • Coral is an animal of the cilantro class, which subsists on lime.  Its length is about 1 cm.  The corals are found in the shallow seas near the coast.
  • In shallow seas, whose depth is about 50-60 meters, sunlight and oxygen are abundant here, so it is a favorable condition for corals.
  • There are millions of corals together, they have a characteristic that they extract lime from their bodies, due to which coral reefs are formed.
  • A coral animal is called a polyp.  The shell of calcium carbonate is found on the body of coral, its shell is called septa.
  • An alga called zooxanthellae grows on the shell of coral, due to these algae, corals appear colorful.  Thus, it can be said that there is a symbiotic relationship between corals and zooxanthellae.
  • The zooxanthellae provide colour, food and protection to the corals, while the coral provides habitat to the zooxanthellae as the zooxanthellae live on their cover.
  • The zooxanthellae make up the sugar by the process of photosynthesis and this sugar makes up 98% of the coral's diet.
  • When corals die in the shallow seas near the coast, other corals build their shells on top of their shells.  By this process, the corals rise above the surface of the sea, forming one layer above the other, so they appear like tree branches.  This is what we call the coral reef.
  • A coral reef is a wall-like structure in shallow seas, which is formed by the stratification of lime-dominated organisms.  These coral reefs are also called coral reefs.

Coral bleaching

  • Coral bleaching is called coral bleaching.  A type of algae called zooxanthellae is found on the corals, due to which the corals appear colorful.  When the zooxanthellae lose their color, then they become white in color, due to which the color of the coral also starts to appear white, this process is called bleaching.
  • The process of photosynthesis gets inhibited due to the turning white of the zooxanthellae because chlorophyll is absent in it.  Due to the interruption of the process of photosynthesis, the zooxanthellae start dying out gradually, since corals depend on these zooxanthellae, so they also start dying slowly.
  • The biggest threat to coral is from a weather condition called Alnino.  The El Nino is a warm current flowing along the Peruvian coast, it appears in the month of December.  Due to the effect of El Nio, an increase in temperature is seen around the world, due to which a lot of weather changes are also seen, which also affects these coral reefs.
  • Bleached coral can regain its former state, but for this it is necessary that the water temperature is normalized and the zooxanthellae are able to perform the process of photosynthesis.  Coral reefs will not be able to achieve normalcy until the zooxanthellae do not grow.

important facts:

  • The names of three islands of Andaman and Nicobar Islands have been changed which are as follows –
  1.  Old name – Changed name
  2.  Ross Island – Netaji Subhas Chandra Bose Island
  3.  Neil Island
  4.  Havelock - Swaraj Dweep
  • (Havelock Island was named after the British general Sir Henry Havelock who served in India during the British administration.)
  • Pamban Island is also known as Rameshwaram Island.
  • Ram Setu is also called Adam's bridge.
  • Little Andaman is the southernmost island of the Andaman Islands and not South Andaman.
  • Andaman and Nicobar Islands are also known as Turquoise Islands.
  • 100 channels are located between Little Andaman and Car Nicobar.
  • Mount Thulier (642 m) is the highest peak of Great Nicobar.
  • The Ten Degree Channel separates the Andaman Islands (Little Andaman Islands) from the Nicobar Islands (Car Nicobar Islands).
  • Bandur Marine Biosphere Reserve, located in the South Andaman and Great Nicobar Islands, is world famous for the world's largest and rarest Giant Robber Crab.