🌍🌎🌏🌐👋 everyone here I am Goutam from "Geography 🌍 " today I compose about "Coral & Coral Reef" which are only exist a far away from the land, in the middle of the sea. On the tropical zone it is mostly found.
It is one kind of sea creatures and it is called polyps. It has various colour also various kind of shape. It is crust by the calciums shell which is released from the body. After died those polyps are gathered in several place which are called "Coral".
Content
- Favourable conditions for the growth of coral
- Coral reef
- Origin of coral reef
- Types of coral reef
∆ Favourable conditions for the growth of coral :-
The polyps are lived mostly on the warm water of sea. When they made a coral reef on that time the temperature must be 17°-30° C. For this reason the coral exist on the middle of 30° N axis to 30° S axis.
For the coral growth the depth of sea must be under 27-30 metres. In this depth the sunlight is entire easily and for that here generate one kind plankton which are the healthy food in coral growth.
The sea water would be quiet and clear, if there stay any silt the the sunlight cann't entire to depth and then plankton can not grow properly.
The percentage of salt in the sea must be 30-38, which is the perfect on growth of plankton and even in the growth of the coral the hardrock also take a part. The coral quickly growth on the hardrock area and make a colony.
∆ Coral Reef :-
From the bone of the died corals the coral reef is made. Actually after died of corals the bones or the calcium shell of corals gathered in many place and made a coral reef. Which is actually placed on a far away from the land and it also exist an around of an Island. The australian "Great Barrier Reef" is world largest coral reef.
∆ Origin of Coral Reef :-
Mainly there are two kind of polyp, one is soft and another is hard. Mostly by the hard coral the coral reef is made narrowly. After the dead of corals the hard calcium shell is gathered, then from this calcium shell another coral is generate from it's calcium shell another coral is generate. Again and again when this is rotated there exit a heap of the coral. In this heap there pressed up many new coral, moss, cockle etc. The this narrow but high boundary is called "coral reef". The coral exist on under of the sea, which are appeared in sea those are coral cay.
∆ Types of Coral Reef :-
According to there formation there are three types of coral reefs are present.
(1) Fringing Reef :-
The fringing reef is actually appear in the near of island, near of the land and in the hardrock area. It is small in it's shape. The top of the reef is not plain. This kind of coral reef attached with the coastal area.
(2) Barrier Reef :-
When a reef exist far away or more than 5 km. distance, there made a reef on equal of the coast this is called barrier reef. It stop the sea traffic for this it is called barrier reef. It is large and so depth. It is detached by the land.
∆ Atolls :-
When a reef made a far away from the land then it is called Atolls. Atolls generate in the middle of sea. In the middle of this Atolls there subsists a lagoon and it's depth is 80-140 m. Atolls looks like a circle.
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