No! They are not plants or flowers. They are not rocks either. Coral Reefs are underwater ecosystem held together by carbon carbonate structures secreted by Corals. A Coral is a colony of genetically identical polyps which are tiny jellyfish-like creatures and are a member of the phylum Cnidaria of Animalia kingdom. So, technically, Corals are invertebrate animals. (Be smart, don’t call them plants)
Where are they found?
Most corals are found in some shallow regions of tropical seas at a depth less than 150 feet. They only cover 0.1 percent area of the surface of the world’s ocean. But the interesting part is, it provides habitat for a quarter of all marine species. Tropical waters contain fewer nutrients yet the largest and strongest corals grow there exposed to the most violent surfs. Even Darwin failed to understand such strange behaviour and sometimes it’s called Darwin’s paradox. Corals don’t need many nutrients because they recycle nutrients. Also, most corals require sunlight to grow so they generally thrive not far below from the surface.
What do they eat?
Corals are colonies of polyps which are simple organisms consisting of a stomach attached to a mouth with tentacles. Photosynthesis by algae, living in their tissue provides corals most of their energy and nutrients. Though some corals in deep ocean prey on small fish and plankton.
On top of it, they provide food for a variety of creatures and maintain an ecosystem of their own. The small fishes hiding in the coral attracts big predators like sharks. Algae and sponges also grow with the coral, which provides food for many sea creatures. For example- the sea turtles which benefit the coral by inhibiting algae and sponges from outgrowing the reef.(The peaceful sea turtles are endangered which in turn, is making the reefs endangered too.)
Here’s a fun fact – sea anemones are relatives to corals and jellyfish. They are predators and live symbiotically with clownfish. Anemones feed on small fishes and shrimps. They paralyze their target by stinging. But they fail to harm clownfish because they cover themselves with a protective layer of mucus. Clownfish use the anemones to protect themselves from other predators and in turn, let anemones feed on those predators. Who’s the real clown now huh?
Why should we care?
There are a lot of reasons why should coral reefs be given more importance-
- they protect our coasts. They absorb the energy of the waves coming from the ocean and reduce coastal erosion, damage from storms. In fact, small islands like Maldives and Lakshadweep cannot exist without the corals.
- they are home to more than 25% of all species of marine life.
- they provide a large portion of food(seafood) for approximately 800 million people, living in coastal areas.
- they provide income to humans through fishing.
- they are the main attraction for tourism for coastal islands.
- by converting free carbon into solid carbonate, they maintain the level of carbon dioxide in the oceans.
- they are also being used in the treatment of cancer, HIV, leukemia, ulcers. There is still so much to know about coral reefs.
- they provide sand. The parrot fish with their bony beaks eat corals and algae but excrete out the limestone into fine sand found in coastal areas. Yes, the warm white sand on the beaches is nothing but mostly fish poop.
Are Coral Reefs in Trouble?
Unfortunately, the answer is yes. The coral reefs, also called the rainforests of the sea, are dying. Overfishing by humans, ocean pollution, and global warming are affecting the fragile ecosystem. We have already lost nearly half of the coral reefs in the last 30 years. When stressed, coral release the algae and turns white leaving their white skeletons, also known as “bleaching”. They are able to regain the algae if the conditions become normal again. If not, they die forever and leave a white graveyard behind.
Scientists also predict that after 15 years all of the coral reefs would be endangered and by 2050, 90% of it would be dead. We are not talking about centuries here, 2050 is not that far away.
What can we do to save corals?
Curbing ocean pollution by stopping industries from disposing of waste into the ocean is effective, but individually there are many small practices you can work on to save our Waterworld-
- be careful not to waste water.
- do not pour chemicals down your drain since eventually, the water will reach the ocean.
- do not litter and recycle as much as you can so the garbage won’t find its way back to water.
- reduce energy use, the oceans are becoming acidic due to increased carbon dioxide in the atmosphere
- reduce the use of fertilizers.
- spread the word. Share the information with your friends and family. Educate people about the importance of coral reefs.
Photo credits – Pixabay