IN264
Gulf of Mannar Marine National Park


Site description (2004 baseline):

Site location and context
The Gulf of Mannar, the first marine Biosphere Reserve of India, off the southern extremity of India, includes a group of 21 islands, located 0.2 to 8 km off the coast. Most of the islands are small, from a few hectares to less than 4 sq. km., running roughly parallel to the coast. The islands are mainly of coral origin. The Gulf of Mannar is the first Marine Biosphere Reserve not only in India, but also in south and southeast Asia. It is about 60 km from Ramanathapuram. The Gulf of Mannar has a coastal length of about 141 km. The International Union for Conservation of Nature and Natural Resources (IUCN) commission on National Parks, and the World Wildlife Fund (WWF), identified the Reserve as being an area of “Particular concern” given its biodiversity and special ‘multiple use’ management status. Mandapam lies on a narrow peninsula projecting from the southeast coast of India, with the Gulf of Mannar to the south and Palk Bay to the north. At the end of the peninsular extension is Pamban Island, which is connected to the mainland by a railway bridge. The inshore region of the Palk Bay is largely muddy, while in the Gulf of Mannar, it is rocky and interspersed with small areas of sand and mud (Balachandran 1995). The mixing of waters of Palk Bay and the Gulf takes place through the Pamban Pass and also through Adam’s Bridge between Dhanushkodi and the west coast of Sri Lanka (Jayaraman 1954). The Gulf of Mannar Marine NP consists of 6.23 sq. km, but the Biosphere Reserve stretches 180 km along the coast and is c. 10 km wide. Forty villages lie within the Biosphere Reserve. There are four or five main islands and lagoons: Manali Island, Hare island, Dhanushkodi lagoon, Kundugal inter-tidal area, Pallaimadam lagoon and Dhanushkodi lagoon.

Key biodiversity

AVIFAUNA: About 187 species of aquatic and terrestrial birds have been identified from this IBA (Balachandran 1990, 1995), which is famous for waders and seabirds. Sometimes >50,000 water birds are found here. Pelagic birds are also recorded (Balachandran 1990). Its proximity to Sri Lanka makes this IBA an important flyway for migratory birds. Among the waders, the Lesser Sand Plover Charadrius mongolus, Curlew Sandpiper Calidris ferruginea and Little Stint Calidris minuta are the most abundant. Red Knot Calidris canutus is a regular winter visitor in small numbers, and the species is not a vagrant as reported previously. The rare Eastern Knot C. tenuirostris has also been recorded from this area. The occurrence of Crab Plovers Dromas ardeola in hundreds indicates that the two islands (Manali and Hare) in the Gulf of Mannar are important habitats for the species, next only to Pirotan Islands in Kutch (coastal northwest India, another IBA) (where two to three thousand individuals were reported to winter regularly). The Bar-tailed Godwit Limosa lapponica, reportedly a straggler in south India, has been recorded in hundreds. The status of Sanderling Calidris alba was confirmed as a regular common winter migrant, after being first recorded by Biddulph (1938) earlier. The marine terns, such as the Lesser Crested Sterna bengalensis and the Sandwich S. sandvicensis commonly occur, and the former was found breeding. The other breeding species at Mandapam are: Little Tern Sterna albifrons, Kentish Plover Charadrius alexandrinus, Stone Plover Esacus magnirostris and Stone Curlew Burhinus oedicnemus. Since Greater flamingos Phoenicopterus ruber frequent this area in several thousands, this IBA ranks third as an important wintering ground for flamingos along the east coast, after Pulicat Lake (IBA) and Great Vedaranyam Swamp. Rare waders in this area are the Broad-billed Sandpiper Limicola falcinellus, Dunlin Calidris alpina, Long-toed Stint Calidris subminuta and Red-necked Phalarope Phalaropus lobatus. The Gulf of Mannar lies within the passage of many migrants such as Black-tailed Godwit Limosa limosa and Broad-billed Sandpiper. Also, 15 species of migratory waders and 8 species of migratory terns were found to summer here especially on the two islands. Along with Chilika Lake in Orissa (an IBA) and Point Calimere in Tamil Nadu (an IBA), the Gulf of Mannar forms an extremely important link for migrant and resident waders. On the Sri Lanka side, about 10 km away, in Jaffna district, there are 4 IBAs (Anatidal-Thondamannar, Araly South-Punale, Kaithady and Kayts Island-Mandativu (Anon. 2003).

OTHER KEY FAUNA: This IBA is very important for the Dugong Dugong dugon, one of the most endangered species of marine mammals on the east coast of India. Several species of cetaceans also occur in the Park. Marine turtles breed in small numbers, and there is a rich marine fauna associated with the reefs and seagrass. Green Tiger Prawn Penaeus semisulcatus is extensively harvested for export.

The Gulf of Mannar NP has 3,600 species of plants and animals.

The Gulf of Mannar and Palk Bay contain some of the most extensive beds of sea-grasses (Hydrocharitaceae and Potamogetonaceae) on the east coast of India. Six of the world’s 12 seagrass genera and 11 of the world’s 50 species, occur in the Gulf. Krusadai Island exemplifies the biological significance of this area. The island harbours three species of seagrass endemic to the Gulf of Mannar, and also a unique Balanoglossus (protochordate) Ptychdera fluva, a taxonomically unique living fossil which links vertebrates with invertebrates. The seagrass beds are extremely important for the Dugong. They also provide food and habitat to five species of marine turtles: Green Chelonia mydas, Olive Ridley Lepidochelys olivacea, Hawksbill Eretmochelys imbricata, Leathery Dermochelys coriacea, and Loggerhead Caretta caretta which is very rare.

About 120 species of coral have been identified from the Gulf of Mannar NP. Mangroves are also very common. 17 species have been identified so far, including Pemphis acidula, which is endemic to the Gulf of Mannar.

Pressure/threats to key biodiversity
MAIN THREATS: Tourism; Illegal trading of sea animals; Fishing; Development projects.

Indiscriminate destruction of the marine fauna and flora continues, despite the preventive efforts of the Fisheries Department. The population of sea turtles and dugong is declining as a result of direct persecution and destruction of the seagrass beds. The alien species Prosopis chilensis has become dominant on some of the islands nearer the coast at the expense of native vegetation, and there have been proposals to plant other exotic tree species on some of the islands. The quarrying of coral for industrial use has now been banned, but several areas of the reef have already been destroyed. The biggest long-term danger to the Gulf of Mannar Marine NP is from the proposed multi-million dollar Sethusamudram Project initiated by the Ministry of Surface Transport. The project involves deepening of the Pamban channel to facilitate movement of coastal ships upto 3,000 tonnes. The BNHS and others have opposed this project as it would destroy the rich marine biodiversity of this biosphere reserve. The Sri Lankan government has communicated its opposition to the project on the same grounds.

Acknowledgements
Key contributors: S. Balachandran and V. Kannan.


Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Gulf of Mannar Marine National Park (India). Downloaded from https://datazone.birdlife.org/site/factsheet/gulf-of-mannar-marine-national-park-iba-india on 27/12/2024.