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

Presented byJitendra KumarPh.D. DFK 1303

Dept. of Fisheries Resources and ManagementCollege of Fisheries, Mangalore

jitendrafishco@gmail.com

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

CLASSIFICATION & TAXONOMY

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.

CORALS- ANIMAL OR PLANT?

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

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

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

Zooxanthellae

Coral polyp

Coral colony

Corals

Coral Reef

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.

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

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.

TYPES OF CORAL REEFS

Fringing reef, Barrier reef, Atoll

Patch reef, Apron reef, Bank reef, Ribbon reef, Table reef, etc..

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)

Types and Identification of coralsBased on their appearance, the reed building corals are classified.

Hard coralsHard 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 coralsMassive 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 coralsBranching corals are characterized by having numerous branches, usually

with secondary branches. They are attractive, colorful and fragile. Its highly used for ornamental purpuses.

Table coralsCorals 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 coralsCup 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 coralsSoft 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.

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.

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

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

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

Pulley Ridge deepest photosynthetic coral reef, Florida

The Raja Ampat Islands Found in Indonesia's  province offer the highest

known marine diversity

STAGHORN CORAL

PILLAR CORAL

Endangered (EN) 2010 IUCN Red List of Threatened Species.

Critically endangered (CR) 2010.4 IUCN Red List of Threatened Species.

PEARL BUBBLE CORAL

MUSHROOM CORAL

Vulnerable (VU) 2010.3 IUCN Red List of Threatened Species

GIANT STAR CORAL

CRISP PILLOW CORAL

StatusVulnerable (VU) 2010.3 IUCN Red List

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).

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.

-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

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

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.

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.

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.

 

THANK YOU