Coral reefs are underwater structures formed from calcium carbonate secreted by coral polyps that live together in colonies. Corals can live over 4,000 years, longer than any other ocean animal. Corals are animals, not plants, that obtain nutrients through photosynthesis via algae living inside them or by catching food with stinging tentacles. Coral reefs are important habitats that are home to 25% of marine species and support tourism, fishing and coastal protection for many communities. However, coral reefs are threatened by pollution, climate change and other human impacts.

1. CORAL REEFS
(Origin and reefs of the India & world)

2. Coral reefs are underwater
structures made from calcium
carbonate secreted by corals.
Most coral reefs are built from stony corals,
and are formed by polyps that live together
in groups.
CORAL REEFS

3. CLASSIFICATION & TAXONOMY

4. Some species of coral can live for over 4,000 years —
longer than any other animal that lives in the ocean,
A study has found.

5. CORALS- ANIMAL OR PLANT?

6. Coral is an ANIMAL!
• Coral is actually an animal.
• They live attached to the sea floor.
• They are the builders of the reef!
• A single coral animal is called a coral
polyp.
• The coral polyps live together in colonies.
The coral polyps live
inside here

7. What do they eat?
Corals obtain food in 2 ways.
1. They use stinging tentacles to catch microscopic animals living in the
plankton.
2. Or they obtain their food from the zooxanthellae. This method of energy
gaining is responsible for 80% of the corals nutrient requirements.
A coral
polyp

8. What do they eat?
• A microscopic type of algae called
zooxanthellae actually live inside corals,
just under their skin.
• Corals are solar-powered just like trees
on land. The algae that live inside the
coral
A coral polyp

9. Zooxanthellae
Coral polyp
Coral colony
Corals
Coral
Reef

10. ORIGIN OF CORAL REEFS
 Most coral reefs were formed after the last glacial
period when melting ice caused the sea level to rise
 This means that most coral reefs are less than 10,000
years old
 The vast majority of these islands are volcanic in origin.

12.  Coral Reefs are structures produced by living
animal colonies,
 found in marine waters containing few nutrients
 Often called rain forests of the sea, due to their
richest biodiversity.
 They occupy less than 0.1% of the world’s ocean
surface, but provide home for 25% of marine
species

13. REEF SKELETON
 The skeletons of stony corals are secreted by
the lower portion of the polyp.
 This process produces a cup, called the
calice, in which the polyp sits.
 The walls surrounding the cup are called the
theca, and the floor is called the basal plate.

14. TYPES OF CORAL REEFS
 Fringing reef, Barrier reef, Atoll
 Patch reef, Apron reef, Bank reef, Ribbon reef,
Table reef, etc..

15. Types
•Fringing reef: larvae attach to sublittoral hard bottom; as corals
grow, a fringing reef is formed along the coast (Caribbean Sea)
•Atoll: last geological stage of sinking volcanic island; circular
reef remains around lagoon, because corals keep growing
upwards on the out-side; calm water and sedimentation prevents
coral growth in the Lagoon (South Pacific)
•Barrier Reef: if land sinks and corals grow upwards, a lagoon
will separate the barrier reef from land (Australia, Great Barrier
Reef)

18.  Types and Identification of corals
Based on their appearance, the reed building corals are classified.
 Hard corals
Hard corals are most often referred to as corals that contain a 'hard' calcium
skeleton and they are also referred to as stony corals and are member of
the order Scleractinia. In most cases these skeleton grow very slowly, i.e. 1
cm a year.
 Massive corals
Massive corals are characteristically ball or rock shaped and relatively slow
growing.
They have very stable profiles; massive corals are relatively undamaged by
strong wave action unless they are dislodged from their holdfasts.
 Branching corals
Branching corals are characterized by having numerous branches, usually
with secondary branches. They are attractive, colorful and fragile. Its
highly used for ornamental purpuses.

19.  Table corals
Corals that form broad horizontal surfaces are commonly called Table
corals, they resemble that of a table. The size of the Table corals may
vary from small round shaped plates to large round tables.
 Cup corals
Cup corals resemble exactly like that of cup. The size may vary from
small cups to large cups and they are locally called as 'Vattai'.
 Soft corals
Soft corals are dominant elements of the reef environment, providing all
sorts of shapes and colors ranging from red and yellow to orange and
purple, they resemble like that of a sponge. They contain minute, spiney
skeleton elements called sclerites. Thus they are not reef building corals
and do not lay new foundations for future corals.
Soft corals are found worldwide in the reef environment. This near-
surface-depth allows for currents which provide the soft corals with
food and oxygen.

20. Why are coral reefs important?
Additional Notes:
-350 million coastal people rely
directly on coral reefs for their food
and survival.
-Coral skeletons break up into small
pieces, and make up the sand of
sandy beaches and even islands.
-Over 20 million scuba divers visit
coral reefs each year.
-Tourism is the largest global
industry, and coral reefs / tropical
islands are one of the main
attractions.
-The economic potential of coral
reef tourism is huge.
-Current annual revenue is
approximately 25 greater than
that of fishing.

21.  Coral reefs (1842) was Darwin’s first monograph.
 Coral reefs was first published in May 1842.
 Darwin brought out a revised second edition in 1872.
 All of this is the result of the accumulation of the calcareous
skeletons of untold billions of simple organisms.
The Complete Work of Charles Darwin Online

22. IMPORTANT REEF STRUCTURES OF WORLD
The Great Barrier Reef
 largest, comprising over 2,900 individual reefs and 900
islands
 Stretching for over 2,600 kilometers off Queensland,
Australia
The Meso-american Barrier Reef System
 stretching 1,000 kilometers

23. The New Caledonia Barrier Reef
 double barrier reef, covering 1,500
kilometers
The Andros, Bahamas Barrier Reef
 following the east coast of Andros
Island, Bahamas,
The Red Sea Reef
 Includes 6000-year-old fringing reefs
located around a 2,000 km coastline

24. Pulley Ridge
 deepest photosynthetic coral reef, Florida
The Raja Ampat Islands
 Found in Indonesia's province offer the highest known
marine diversity

25. STAGHORN CORAL
PILLAR CORAL
Endangered (EN) 2010 IUCN Red List of Threatened Species.
Critically endangered (CR) 2010.4 IUCN Red List of Threatened
Species.

26. PEARL BUBBLE
CORAL
MUSHROOM
CORAL
Vulnerable (VU) 2010.3 IUCN Red List of Threatened Species

27. GIANT STAR CORAL
CRISP PILLOW CORAL
Status
Vulnerable (VU) 2010.3 IUCN Red List

28. CORAL REEFS DISTRIBUTION IN INDIA
 India has four major reef ecosystems, having all three reef
types, atoll, fringing and barrier.
 The total area of coral reef in India is estimated to be 2,375
sq.km.
 The mainland coast of India has two widely seperated areas
containing reefs, the Guf of Kuttch is located in the
northwest (Gujarat) and the Palk Bay and Gulf of Mannar
are located in the south-east (Tamilnadu).

29.  The Andaman and Nicobar Islands in Bay of Bengal
have fringing reefs around many islands, and a long
barrier reef (329km) on the west coast.
 The Lakshadweep in Arabian Sea also has
extensive reefs especially atolls.

30. -Some coral reefs are over 100 million years
old.
-Tropical rainforests have millions of insect
species and therefore have the highest
biodiversity on earth.
-Coral reefs are the largest living structures
visible from outer space (the Great Barrier
Reef is over 2000 km long).
-Coral reefs worldwide cover an area of
284,300 square km, around 1% of the total
area of the world’s oceans.
Interesting Coral Reef Facts

31. Why are coral reefs important?
• Habitat: They are home to 33%
of all known fish species.
•Nursery: And a nursery ground
for over 25% of all marine species.
Photo by J. RandallPhoto by Dee Wescott
Photo by MacGillivray Freeman Films

32. Why are coral reefs important?
•Income: they provide millions of
dollars of income annually for people
living by coral reefs.
•Medical Research: coral reefs have the
potential to be used as medical cures to
treat cancer, heart disease, HIV and
arthritis among others.
• Protection: they protect 20% of the
world’s coast from wave erosion.
• Food: they are a food source for
millions of people.
• Tourism: coral reefs attract
tourists from all over the world.

33. REGULATORY MEASURES
 Legislative/Regulatory Instruments
-The Wildlife (Protection) Act, 1972 : All Reef-building, Fire and
Sea Fan Corals put in Schedule-I of the Act (Prohibited from
exploitation)
-Environment (Protection) Act, 1986 : Section 5 of the Act delegates
powers to State Governments, and UTs for taking punitive action.
-Coastal Regulation Zone Notification, 1991 :
Management actions are activities to promote use and that protect and conserve natural
resources.

34. CONT..
-Coastal Regulation Zone Notification, 1991 : Places corals, coral
reefs, and marine parks in Coastal Regulation Zone-I(i),
i.e, ecologically sensitive, and important areas.
Constitutes National Coastal Zone Management Authority
(NCZMA) at the Centre, and 13 CZMAs at States/Union
Territories.
- Formulation of Integrated Coastal Zone Management Plans
(ICZMP) by Coastal States.

35. THANK YOU