04 September 2015

What is a Coral Reef?

If you are out snorkeling in the Maldives, you will come across a variety of corals of different shapes (e.g. table, branching, boulder, disc finger shaped), sizes, and colors. The architects and builders of these beautiful structures are actually tiny translucent, soft-bodied polyps. Thousands of these tiny polyps work together by secreting a limestone base around them, to build the beautiful corals that forms into the reef we observe today..

Small fishes taking refuge in a branching coral colony

If you closely observe the corals, especially during night, you are likely to see tentacles projecting out of the corals. Polyps use the tentacles to capture zooplanktons in the water for nourishment. In addition, most polyps houses algae (zooxanthellae), in their tissues, which produces its own food (using sunlight, similar to plants), which in turn the polyps uses as their main source of nourishment.   Hence, corals occur mostly in clear tropical waters, which receives sufficient sunlight.

Another thing that you will notice are the colorful fishes, clams, starfishes, rays, sea cucumbers, snails and other creatures that takes home in the nooks and crannies of the reef. Reefs are a rich source of food, and safe refuge for a wide variety of marine life. Coral reefs are also an important source of income, and protein for coastal communities and small island nation such as the Maldives. Damage to coral reefs comes with very high environmental, economic, and social cost.

Corals are also highly sensitive to temperature changes, slight sea temperature fluctuations can have devastating impact on the reefs. During the El-NiƱo event in 2010, large areas of the reefs were bleached. When corals are stressed, coral polyps expels the algae in their tissue -which is the main provider of nourishment- leaving the corals white. Consequently, human induced global warming, and climate change is expected to have devastating impact on the coral reefs. In addition to man-made disasters, corals also faces natural predators such as the Crown-of-Thorn Sea Stars, and Drupella snails, which in large numbers, can decimate large areas of the reef.

Reducing the stress (e.g. pollution, overfishing, coral mining) on the coral reef ecosystem is the best way to ensure, that the reefs bounce back after an event such as bleaching, or explosion of coral predators. If you are healthier and stronger, you are more likely to heal faster, the same concept applies to the reefs. 

There are few things that you can do to reduce stress, and prevent damage to the coral reefs; when snorkeling or scuba diving. Avoid touching or taking corals, avoid stepping/trampling on corals, keep your gears secure and take care not to hit the reef with your fins. You should avoid littering into the ocean, when corals and other marine life are tangled up with plastic bags or other waste materials they slowly die out. Let's do our part to ensure this beautiful, rich, dynamic ecosystem we are blessed with stays that way!