Building blocks of Coral reefs

Corals from the basic biological building blocks of our coral reefs. Coral reefs are beautiful places of serenity, mystery, wonder and unmatched attraction that keeps one spellbound. Making you soon forget the passage of time. Even after repeated visits, the attraction of reefs is so enduring that the visitor is rarely able to break free from this mysterious beckoning that commands the visitor’s undiminished awe and attention.

Where you can find Coral reefs?

Coral reefs probably represent the most diverse ecosystems on our planet and have a very rich biological diversity. Reefs are also highly productive ecosystems that are referred to as the rainforests of the seas. Coral reefs are found in shallow tropical seas and cover barely 0.18% of the world’s oceans. In Sri Lanka, they are not very extensive and reefs make up only 2 to 3% of our shoreline.

Corals can be broadly divided into “hard” and “soft” corals. The term “coral” is the common name that is usually used for hard corals making up the order Scleractinia, their “hard” nature being due to their hard limestone skeletons. The Scleractinia have reef-building (mostly “hermatypic”) corals and non-reef-building (mostly “ahermatypic”) corals. Ahermatypic corals normally live in ocean depths without sunlight whereas hermatypic corals need sunlight to live and are therefore found in shallower seas. The soft corals usually do not have hard skeletons while the non-scleractinian corals are organism that builds skeletons similar to those of the scleractinian corals.

Who is Coral Polyp?

The basic living organism of all corals is a tiny simple animal called the coral polyp. Inside the coral polyps are live microscopic plant cells (an alga), called zooxanthellae. These very tiny plants are able to manufacture organic food by tapping the sun’s energy. Most of the coral’s nutrition is obtained from this food and a similar part by capturing the zooplankton found in the water. Zooxanthellae also increase the rate at which coral polyps build their limestone skeletal framework and give coral their colour. Without zooxanthellae, corals would appear white or “bleached”.

How Coral reefs stop Coastal Erosion?

Coral polyps mostly live in colonies. The colonies being formed by budding. Although each tiny polyp of a reef-building hermatypic coral builds only its own tiny limestone cup (a corallite) around itself. The numerous polyps of the coral colony cement their individual limestone cups together into a larger structure. These limestone structures of the corals' colonies are cemented together by coralline algae from the strong reef framework. Corals with their skeleton making our reefs. Therefore, they can stand strong wave action and break the force of the waves before they hit and eroded the shore. Coral reefs are also important habitats and nursery areas for fish and shellfish.