CORALS are known as the underwater gardens of the ocean. Besides provid­ing shelters to 25% of marine species, they amaze us with their myriad colours of beauty.

But little do we know that the vivid colours of corals come from a type of algae that resides in it, called zooxanthellae.

They also provide nutrients to corals through photosynthesis to keep them healthy. In return, the corals provide shelter to their algae friends.

They work in a symbiotic relationship whereby their lives depend on each other through the sharing of their resources.

However, when they are put into a stressed condition such as the increase in water temperature or pollution, their relationship turns sour.

The corals expel the algae, exposing their whitish bony like structure, and thus, making them “bleached”. Coral bleaching does not signify that they are dead corals, but it simply means they are more vulnerable to diseases, and even mortality.