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Shark and Healthy Coral Reefs

Coral reefs are the most diverse of all marine ecosystems. The coral reefs teem with life and a huge cross section of marine species are dependent on these reefs for existence. These reefs are like the tropical forest of the Ocean.

The Sharks have been swimming the waters of the Ocean for more than 400 million years, even before the dinosaurs had arrived. Sharks are the apex predators in their ecosystem and have few natural predators. They being the apex predator prey on animals down on the food chain, which help regulate and maintain the balance of the ecosystem.

Corals thrive on zooxanthellae, microscopic algae that live in their tissue. Through photosynthesis the zooxanthellae provide oxygen and food to the coral. So how does a shark help the coral? In a pristine coral reef there is a hierarchy, its Sharks followed by Mesopredators, Herbivores and Algae. The presence of the Shark makes the other predatory fishes stay away from that area allowing the herbivores to pluck on the algae that grows on the Coral. It has been noticed that places where there are fewer Sharks, the complete ecosystem of that reef has changed. With lesser Shark in the area other Mesopredators frequent the area, prey on the Parrot fish which eats the algae. Absence of this balance makes the algae grow and take over the Coral.

The Shark has always been portrayed in a way which always instilled fear in our minds. However, it plays a very important part in sustaining the marine ecosystem.


By: Madhuchanda Saxena