Coral reefs: East Coast of India
Gulf of Mannar
The Gulf of Mannar reefs are found around a chain of 21
islands that lie along the 140 km stretch between Tuticorin
and Rameswaram. These islands are located between latitude 8
47’N and 9
15’N and longitude 78
12’E and 79
14’E. The islands lie at an average distance of 8 km from
the main-land. They are part of the Mannar Barrier reef,
which is 140 km long and 25 km wide between Pamban
and Tuticorin. Different types of reef forms such as shore,
platform, patch, and fringing type are observed in the Gulf
of Mannar (Venkataraman et al., 2003). The islands have
fringing coral reefs and patch reefs around them. Narrow
fringing reefs are located mostly at a distance of
50–100 m from the islands. On the other hand, patch reefs
rise from depths of 2–9 m and extend to 1–2 km in length
with width of as much as 50 m. Reef flat is extensive in
almost all the reefs in the Gulf of Mannar. Reef vegetation
is richly distributed on these reefs. Reef flat and reef vegetation including algae occupies 65 and 14 sq km, respectively (D.O.D and S.A.C., 1997). Pillai (1986) had
provided a comprehensive account of the coral fauna of
this region. There are about 94 species of corals belonging
to 32 genera in the Gulf of Mannar. The most commonly
occurring genera of corals are Acropora, Montipora, and
Porites. Extensive sea grass beds are present; green turtles, olive ridley turtles, and dugongs are dependent on
these sea grasses as their feeding ground.
Andaman and Nicobar Islands
The Andaman and Nicobar group of Islands is located in
the South East of the Bay of Bengal, between 6
–14
N latitude and 91
–94
E longitude. They are the emerged part
of a plate edge mountain chain and lie on a ridge that
extends southward from the Irrawaddy delta area of
Burma, continuing the trend of the Arakan Yoma range.
The Andaman and Nicobar group of islands consist of
530 islands, of which only 38 are inhabited, along with
a number of exposed islets and rocks. The principal of
these is the North Andaman, Middle Andaman with
Ritchies archipelago in the east, South Andaman, little
Andaman, Baratang, and Rutland Island. The coral reefs
are of fringing type and except for a few investigation
reports, the reefs of the area still largely remain unknown.
Atoll Reefs
Fringing Reefs
Gulf of Mannar
Lakshadweep
Islands
Arabian
sea
Bombay
Gulf of Kutch
India
Malvan
Goa
Anjadip Island
Palk Bay
Sri Lanka
Nicobar
Islands
Andaman
Islands
Bay of Bengal
Madras
Burma
Bangladesh
Indian Ocean
Tro pic of Can cer
Coral Reefs of India, Figure 1 Major coral reef areas in India.
268
CORAL REEFS OF INDIA
Gulf of Mannar
The Gulf of Mannar reefs are found around a chain of 21
islands that lie along the 140 km stretch between Tuticorin
and Rameswaram. These islands are located between latitude 8
47’N and 9
15’N and longitude 78
12’E and 79
14’E. The islands lie at an average distance of 8 km from
the main-land. They are part of the Mannar Barrier reef,
which is 140 km long and 25 km wide between Pamban
and Tuticorin. Different types of reef forms such as shore,
platform, patch, and fringing type are observed in the Gulf
of Mannar (Venkataraman et al., 2003). The islands have
fringing coral reefs and patch reefs around them. Narrow
fringing reefs are located mostly at a distance of
50–100 m from the islands. On the other hand, patch reefs
rise from depths of 2–9 m and extend to 1–2 km in length
with width of as much as 50 m. Reef flat is extensive in
almost all the reefs in the Gulf of Mannar. Reef vegetation
is richly distributed on these reefs. Reef flat and reef vegetation including algae occupies 65 and 14 sq km, respectively (D.O.D and S.A.C., 1997). Pillai (1986) had
provided a comprehensive account of the coral fauna of
this region. There are about 94 species of corals belonging
to 32 genera in the Gulf of Mannar. The most commonly
occurring genera of corals are Acropora, Montipora, and
Porites. Extensive sea grass beds are present; green turtles, olive ridley turtles, and dugongs are dependent on
these sea grasses as their feeding ground.
Andaman and Nicobar Islands
The Andaman and Nicobar group of Islands is located in
the South East of the Bay of Bengal, between 6
–14
N latitude and 91
–94
E longitude. They are the emerged part
of a plate edge mountain chain and lie on a ridge that
extends southward from the Irrawaddy delta area of
Burma, continuing the trend of the Arakan Yoma range.
The Andaman and Nicobar group of islands consist of
530 islands, of which only 38 are inhabited, along with
a number of exposed islets and rocks. The principal of
these is the North Andaman, Middle Andaman with
Ritchies archipelago in the east, South Andaman, little
Andaman, Baratang, and Rutland Island. The coral reefs
are of fringing type and except for a few investigation
reports, the reefs of the area still largely remain unknown.
Atoll Reefs
Fringing Reefs
Gulf of Mannar
Lakshadweep
Islands
Arabian
sea
Bombay
Gulf of Kutch
India
Malvan
Goa
Anjadip Island
Palk Bay
Sri Lanka
Nicobar
Islands
Andaman
Islands
Bay of Bengal
Madras
Burma
Bangladesh
Indian Ocean
Tro pic of Can cer
Coral Reefs of India, Figure 1 Major coral reef areas in India.
268
CORAL REEFS OF INDIA