Shelter under the sea: Coral reefs

Corals are creatures which live in the deep regions of tropical waters. Reefs, where many creatures live together, are formed from the limestone skeletons of dead corals cemented together by the action of coralline algae. Reefs can extend over very broad areas. Scientists compare reefs to tropical rainforests because, like rainforests, they are centers of diversity. The coral reefs are home to more than 2,000 species of fish, 5,000 species of mollusks, 700 species of corals and countless other forms of crabs, sea urchins, brittle stars, sea cucumbers and worms of different groups.

Polyps are small marine animals which live in coral reefs. Many coral polyps have symbiotic algae that live inside them. Algae contain chlorophyll and therefore, they can photosynthesize. Algae are rich in oxygen but poor in nutrients. Like all other plants, algae, too, need nitrates and phosphates. That is why it is so important for these creatures to live together. Unable to live on their own, they survive by making use of one another.

The polyp provides food to the algae with its waste products. The algae store the waste products as ammonia and then break them down into nitrogen phosphorus, which is then used for energy. The polyp also provides shelter for the algae by protecting it against predators. In return, the algae provide food to the polyps through photosynthesis. Thus, polyps obtain the energy they need to construct their limestone skeleton.

As in all other creatures that lead a symbiotic life, all the needs of both creatures, in the symbiotic life between polyp and algae, are met in the easiest way. It is apparent that Who has joined these two creatures together is a sole Creator Who is aware of the needs of them both. These creatures have been created by Allah in a way in which they complement each other and meet each other's needs.

Allah introduces us to His endless artistry and boundless knowledge through the various creatures He has created under the sea and the matchless designs and amazing characteristics of them all. Allah reminds us of this in the Qur'an:

And also the things of varying colors He has created for you in the earth. There is certainly a Sign in that for people who pay heed. It is He who made the sea subservient to you so that you can eat fresh flesh from it and bring out from it ornaments to wear. And you see the ships cleaving through it so that you can seek His bounty, and so that hopefully you will show thanks. (Surat an-Nahl: 13-14)