2. INTRODUCTION
➢What are Coral Reefs
➢Types of Coral Reefs
➢Favourable conditions of Coral Reefs
➢What is Coral Bleaching
➢Importance of Coral Reefs
➢Threats to Coral Reefs
3. Coral Reefs
➢A reef is a strip or ridge of rocks, sand, or coral that rises to or near the surface of a
body of water.
➢Coral is an ecosystem wherein they exist as individual polyps or as colonies and
communities.
➢Corals are found throughout the oceans, from deep, cold water to shallow, tropical
waters.
➢Polyp: a small sea animal that has a body shaped like a tube and their hard outer
skeleton made of calcium.
4. Types of Coral Reefs
➢ Fringing Reefs: These reefs form borders along the shoreline and surrounding
island. Such reefs are found near Rameshwaram in Gulf of Mannar.
➢ Barrier Reefs: These reefs also border shorelines, but at a greater distance.
They are separated from their adjacent landmass by a lagoon.
➢ Atolls: These are usually circular or oval, with a central lagoon. Atolls are far
more common in the pacific than any other ocean.
5. Favourable conditions for
coral reefs
➢Found mainly in warmer tropical seas.
➢Clear and shallow water.
➢Sunlight for algae.
➢They grow best in warm water.
6. Coral bleaching
Coral bleaching is a process when coral become white due to various stressors such
as changes in temperature, light or nutrients. It occurs when coral polyps expel the
zooxanthellae that live inside their tissue.
Causes of coral bleaching
➢Overfishing
➢Flooding
➢High and low temperature
➢Nutrient overloading
7. Importance of coral reefs
➢Coral reef ecosystem are less than 0.1% of the ocean area but
provide food and shelter to 25% of all marine species.
➢They support fish stocks.
➢Most diverse and valuable ecosystems on earth.
➢Called as rainforest of the sea due to their astounding richness of life.
8. Threats to coral reef
➢Pollution
➢Overfishing
➢Removal of coral for building and making cement.
➢climate change
➢Addition of sediment.
9. References
➢ "How Reefs Are Made". Coral Reef Alliance. 2021. Archived from the original on 30
October 2021. Retrieved 19 April 2022
➢ "Where are Corals Found?". NOAA Coral Reef Conservation Program. NOAA. 13
May 2011. Archived from the original on 4 March 2016. Retrieved 24 March 2015
➢ Cesar, H.J.S.; Burke, L.; Pet- Soede, L. (2003). The Economics of Worldwide Coral
Reef Degradation. The Netherlands: Cesar Environmental Economics Consulting.
p. 4. Retrieved 21 September 2013.
➢ Greenfield, Patrick (17 September 2021). "Global coral cover has fallen by half
since 1950s, analysis finds". The Guardian. Retrieved 18 September 2021.
