The Gulf of Mannar Marine National Park is a protected area of India consisting of 21 small islands (

islet An islet is a very small, often unnamed island. Most definitions are not precise, but some suggest that an islet has little or no vegetation and cannot support human habitation. It may be made of rock, sand and/or hard coral; may be permanent ...

s) and adjacent

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Co ...

s in the

Gulf of Mannar The Gulf of Mannar ( ) is a large shallow bay forming part of the Laccadive Sea in the Indian Ocean with an average depth of .

in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

. It lies 1 to 10 km away from the east coast of

Tamil Nadu Tamil Nadu (; , TN) is a States and union territories of India, state in southern India. It is the List of states and union territories of India by area, tenth largest Indian state by area and the List of states and union territories of India ...

, India for 160 km between

Thoothukudi Thoothukudi (formerly Tuticorin) is a port city, a municipal corporation and an industrial city in Thoothukudi district in the Indian state of Tamil Nadu. The city lies in the Coromandel Coast of Bay of Bengal. Thoothukudi is the capital and he ...

(Tuticorin) and Dhanushkodi. It is the core area of the

Gulf of Mannar Biosphere Reserve The Gulf of Mannar Marine National Park is a protected area of India consisting of 21 small islands (islets) and adjacent coral reefs in the Gulf of Mannar in the Indian Ocean. It lies 1 to 10 km away from the east coast of Tamil Nadu, Indi ...

which includes a 10 km buffer zone around the park, including the populated coastal area. The park has a high

diversity Diversity, diversify, or diverse may refer to: Business *Diversity (business), the inclusion of people of different identities (ethnicity, gender, age) in the workforce *Diversity marketing, marketing communication targeting diverse customers * ...

of plants and animals in its marine,

intertidal The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of Marine habitat, habitats with var ...

and near

shore A shore or a shoreline is the fringe of land at the edge of a large body of water, such as an ocean, sea, or lake. In physical oceanography, a shore is the wider fringe that is geologically modified by the action of the body of water past a ...

habitats. Public access inside the park is limited to

glass-bottom boat A glass-bottom boat is a boat with sections of glass, panoramic bottom glass or other suitable transparency (optics), transparent material, below the waterline allowing passengers to observe the underwater environment from within the boat. The v ...

rides. It was established as a National Park in 1986.

Geography

The park is part of the 140 km long and 25 km wide Mannar

barrier reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Co ...

. It lies between 8° 47' to 9° 15' N latitude and 78° 12' to 79° 14' E longitude. The 21 islands vary from 0.25 ha (.6 acre) to 130 ha. (321.2 acres). The total area of the islands is . The islands (listed southwest to northeast)

Tuticorin Thoothukudi (formerly Tuticorin) is a port city, a municipal corporation and an industrial city in Thoothukudi district in the Indian state of Tamil Nadu. The city lies in the Coromandel Coast of Bay of Bengal. Thoothukudi is the capital and ...

group: (4 islands)
Vaan, 16.0 ha
Koswari, 19.50 ha
Vilanguchalli, 0.95 ha , now 1 m below mean low tide level as a result of excessive coral mining.
Kariyachalli, 16.46 ha

Vembar Vembar is a village panchayat in Thoothukudi district in the Indian state of Tamil Nadu. Situated along the East Coast Road at the north end of the district, Vembar has two panchayats - Vembar South and Vembar North. Vembar is located near ...

group: (3 islands)
Uppu Thanni, 22.94 ha, elevation 4 m
Puluvini Challi, 6.12 ha, elevation 5.5 m
Nalla Thanni, 101.00 ha, elevation 11.9 m (recently populated)

Kilakarai Kilakarai (alternatively spelled Kilakkarai or Keelakarai) is a municipality in Ramanathapuram district in the Indian state of Tamil Nadu. As of 2011, the town had a population of 38,355. Kilakarai is one of the Taluka in Ramanathapuram Distri ...

group: (7 islands)
Anaipar, 11.00 ha, elevation 2.1 m
Vali Munai, 6.72 ha, elevation 1.2 m
Poovarasan Patti, 0.50 ha, elevation 1.2 m
Appa, 28.63 ha, elevation 6.4 m
Talairi, 75.15 ha, elevation 2.7 m
Valai 10.10 ha, elevation 3.0 m
Mulli, 10.20 ha, elevation 1.2 m AMS-Gulf of Mannar (SW)

Mandapam Mandapam is a panchayat town in Ramanathapuram district in the Indian state of Tamil Nadu. The famed Pamban Railway bridge and Vehicular bridge lie to the East of this Panchayat Town. Mandapam is Tamil Nadu’s largest refugee camp for Sri L ...

group:(7 islands)
Musal, 124.00 ha, elevation 0.9 m (recently populated)
Manoli, 25.90 ha
Manoli-Putti 2.34 ha
Poomarichan 16.58 ha
Pullivasal, 29.95 ha
Kurusadai, 65.80 ha was recently populated. Its surrounding shallow waters harbour three species of seagrass that are found nowhere else in India. Representatives of every animal phylum known (except amphibians) are found on this island.
Shingle, 12.69 ha, elevation .6m Tidal amplitude in the area is about .5m. There were two more islands named Pandayan and Punnaiyadi at that were destroyed for construction of the new Tuticorn Port facilities.

Flora

The park includes marine components such as

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...

communities,

sea grass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the orde ...

es, and

mangrove A mangrove is a shrub or tree that grows in coastal saline water, saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evoluti ...

s. Mangroves dominate the intertidal zones of the park islands. They consist of species of the genera ''

Rhizophora ''Rhizophora'' is a genus of tropical mangrove trees, sometimes collectively called true mangroves. The most notable species is the red mangrove (''Rhizophora mangle'') but some other species and a few natural hybrids are known. ''Rhizophora'' ...

'', ''

Avicennia ''Avicennia'' is a genus of flowering plants currently placed in the bear's breeches family, Acanthaceae. It contains mangrove trees, which occur in the intertidal zones of estuarine areas and are characterized by its "pencil roots", which are ...

'', ''

Bruguiera ''Bruguiera'' is a plant genus in the family Rhizophoraceae. It is a small genus of five mangrove species and three hybrids of the Indian and west Pacific Ocean region, its range extending from East Africa and Madagascar through coastal India ...

'', '' Ceriops'' and ''

Lumnitzera ''Lumnitzera'' is an Indo-West Pacific mangrove genus in the family Combretaceae. An English common name is black mangrove. (However, "black mangrove" may also refer to the unrelated genus ''Avicennia''.) ''Lumnitzera'', named after the German ...

''. The introduced tree genus ''

Prosopis ''Prosopis'' is a genus of flowering plants in the family Fabaceae. It contains around 45 species of spiny trees and shrubs found in subtropical and tropical regions of the Americas, Africa, Western Asia, and South Asia. They often thrive in ari ...

'' is dominant on land in all the islands. The flowering herb ''

Pemphis acidula ''Pemphis acidula'', commonly known as bantigue (pron. ) or mentigi, is a species of flowering plant in the family Lythraceae. It is a mangrove found throughout most of the tropical Indo-Pacific growing on rocky shores. The genus ''Pemphis'', to ...

'' (family

Lythraceae Lythraceae is a family of flowering plants, including 32 genera, with about 620 species of herbs, shrubs, and trees. The larger genera include ''Cuphea'' (275 spp.), ''Lagerstroemia'' (56), ''Nesaea'' (50), ''Rotala'' (45), and ''Lythrum'' (35). ...

) is the only endemic plant species. 12 species of sea grass and 147 species of seaweeds were recorded. This vegetation provides important feeding grounds for vulnerable marine mammals such as the

dugong The dugong (; ''Dugong dugon'') is a marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees. It is the only living representative of the once-diverse family Dugongidae; its closest m ...

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

green turtle The green sea turtle (''Chelonia mydas''), also known as the green turtle, black (sea) turtle or Pacific green turtle, is a species of large sea turtle of the Family (biology), family Cheloniidae. It is the only species In biology, a spec ...

s and

olive ridley turtle The olive ridley sea turtle (''Lepidochelys olivacea''), also known commonly as the Pacific ridley sea turtle, is a species of turtle in the family Cheloniidae. The species is the second-smallest and most abundant of all sea turtles found in th ...

Fauna

Vertebrates The dugong, a vulnerable

marine mammal Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They are an informal group, unified only by their reli ...

, is the flagship mammal of the park. It is an important habitat for the

cetacean Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel them ...

Indo-Pacific bottlenose dolphin The Indo-Pacific bottlenose dolphin (''Tursiops aduncus'') is a species of bottlenose dolphin. This dolphin grows to long, and weighs up to . It lives in the waters around India, northern Australia, South China, the Red Sea, and the eastern ...

finless porpoise ''Neophocaena'' is a genus of porpoise native to the Indian and Pacific oceans, as well as the freshwater habitats of the Yangtze River basin in China China, officially the People's Republic of China (PRC), is a country in East Asia. ...

spinner dolphin The spinner dolphin (''Stenella longirostris'') is a small dolphin found in off-shore tropical waters around the world. It is famous for its acrobatic displays in which it rotates around its longitudinal axis as it leaps through the air. It is a ...

common dolphin The common dolphin (''Delphinus delphis'') is the most abundant cetacean in the world, with a global population of about six million. Despite this fact and its vernacular name, the common dolphin is not thought of as the archetypal dolphin, wit ...

Risso's dolphin Risso's dolphin (''Grampus griseus'') is a dolphin, the only species of the genus ''Grampus''. Some of the closest related species to these dolphins include: pilot whales (''Globicephala'' spp.), pygmy killer whales (''Feresa attenuata''), melon ...

melon-headed whale The melon-headed whale (''Peponocephala electra''), also known less commonly as the electra dolphin, little killer whale, or many-toothed blackfish, is a toothed whale of the oceanic dolphin family (Delphinidae). The common name is derived fro ...

, and

dwarf sperm whale The dwarf sperm whale (''Kogia sima'') is a sperm whale that inhabits temperate and tropical oceans worldwide, in particular continental shelves and slopes. It was first described by biologist Richard Owen in 1866, based on illustrations by n ...

. Larger whales include

sperm whale The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the genus ''Physeter'' and one of three extant species in the sperm whale famil ...

minke whale The minke whale (), or lesser rorqual, is a species complex of baleen whale. The two species of minke whale are the common (or northern) minke whale and the Antarctic (or southern) minke whale. The minke whale was first described by the Danish n ...

Bryde's whale Bryde's whale ( Brooder's), or the Bryde's whale complex, putatively comprises three species of rorqual and maybe four. The "complex" means the number and classification remains unclear because of a lack of definitive information and research ...

sei whale The sei whale ( , ; ''Balaenoptera borealis'') is a baleen whale, the third-largest rorqual after the blue whale and the fin whale. It inhabits most oceans and adjoining seas, and prefers deep offshore waters. It avoids polar and tropical ...

, and critically endangered species including

humpback whale The humpback whale (''Megaptera novaeangliae'') is a species of baleen whale. It is a rorqual (a member of the family Balaenopteridae) and is the only species in the genus ''Megaptera''. Adults range in length from and weigh up to . The hu ...

fin whale The fin whale (''Balaenoptera physalus''), also known as finback whale or common rorqual and formerly known as herring whale or razorback whale, is a cetacean belonging to the parvorder of baleen whales. It is the second-longest species of cet ...

, and

blue whale The blue whale (''Balaenoptera musculus'') is a marine mammal and a baleen whale. Reaching a maximum confirmed length of and weighing up to , it is the largest animal known to have ever existed. The blue whale's long and slender body can ...

. About 510 (23%) of the 2,200 fin fish species in Indian waters are found in the Gulf, making it the most highly diverse fish habitat in India. Coral associated ornamental fishes of the family Chaetodontidae (

butterfly fish The butterflyfish are a group of conspicuous tropical marine fish of the family Chaetodontidae; the bannerfish and coralfish are also included in this group. The approximately 129 species in 12 genera are found mostly on the reefs of the Atla ...

parrotfish Parrotfishes are a group of about 90 fish species regarded as a family (Scaridae), or a subfamily (Scarinae) of the wrasses. With about 95 species, this group's largest species richness is in the Indo-Pacific. They are found in coral reefs, ro ...

, ''

Amphiprion ''Amphiprion'' is a genus of ray-finned fish which comprises all but one of the species of clownfish or anemonefish in the subfamily Amphiprioninae of the family Pomacentridae. Species The following species are classified in the genus ''Amphipri ...

'' spp. (

clown fish Clownfish or anemonefish are fishes from the subfamily Amphiprioninae in the family Pomacentridae. Thirty species of clownfish are recognized: one in the genus '' Premnas'', while the remaining are in the genus ''Amphiprion''. In the wild, t ...

), ''

Holocentrus ''Holocentrus'' is a genus of squirrelfishes found in the Atlantic Ocean. Species There are currently two recognized species in this genus: * '' Holocentrus adscensionis'' ( Osbeck, 1765) (Squirrelfish) * '' Holocentrus rufus'' (Walbaum Walbaum ...

'' spp. (squirrel fish), ''Scarus'' spp. (

parrot fish Parrotfishes are a group of about 90 fish species regarded as a family (Scaridae), or a subfamily (Scarinae) of the wrasses. With about 95 species, this group's largest species richness is in the Indo-Pacific. They are found in coral reefs, ro ...

), ''Lutjanus'' spp. (snappers) and ''Abudefduf saxatilis'' (

sergeant major Sergeant major is a senior non-commissioned rank or appointment in many militaries around the world. History In 16th century Spain, the ("sergeant major") was a general officer. He commanded an army's infantry, and ranked about third in the ...

) are abundant. A unique endemic species of

Balanoglossus ''Balanoglossus'' is a genus of ocean-dwelling acorn worms (Enteropneusta). It has zoological importance because, being hemichordates, they are an "evolutionary link" between invertebrates and vertebrates. ''Balanoglossus'' is a deuterostome ...

– Ptychodera fluva, a living fossil that links invertebrates and vertebrates, has been recorded only at Kurusadai. Invertebrates Four species each of

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

and

lobster Lobsters are a family (biology), family (Nephropidae, Synonym (taxonomy), synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs ...

, 106 species of

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

, 17 species of

sea cucumber Sea cucumbers are echinoderms from the class Holothuroidea (). They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothuria ...

, and 466 species of

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

including 271

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

s, 174

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

s, 5

polyplacophoran Chitons () are marine (ocean), marine molluscs of varying size in the class (biology), class Polyplacophora (), formerly known as Amphineura. About 940 Extant taxon, extant and 430 fossil species are recognized. They are also sometimes known ...

s, 16

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s and 5 scaphopods, 108 species of

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

, and 100 species of

echinoderm An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea ...

occur in the Gulf. The coral fauna includes 106 species from 30 genus of hermatypes and 11 species from 10 genus of ahermatypes, including 13 new species, giving a total of 117 species from 14 families and 40 genus. The reefs in this area are narrow

fringing reef A fringing reef is one of the three main types of coral reef. It is distinguished from the other main types, barrier reefs and atolls, in that it has either an entirely shallow backreef zone (lagoon) or none at all. If a fringing reef grows direc ...

s located 150 to 300 m. from the shore of the islands and patch reefs rising up from depths of 2 to 9 m. and extending up to 2 km. long and 50 m. wide. Large areas of these reefs are in generally poor condition due to destructive human activities of the 150,000 persons living along the coast. Nutrient and other pollution loads are high due to agriculture, deforestation, industry, urbanization and septic pollution. It appears that the coral reefs of the Gulf of Mannar Marine National Park seem to be healthy and in good condition, despite high rates of sedimentation and other threats. However, live coral cover is only about 35%. Various algae cover much of the dead coral.

Stony coral Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a ...

species of families

Poritidae Poritidae is a family of stony corals. Members of the family are colonial hermatypic (reef-building) corals. They are variable in size and form but most are massive, laminar or ramose as well as branching and encrusting. The corallites are compa ...

and

Faviidae Mussidae is a family of stony coral in the order Scleractinia. Following a taxonomic revision in 2012, the family is now restricted to species found in the Atlantic Ocean, with Pacific species transferred to the new family Lobophylliidae. Many ...

constitute the dominant reef builders here. Coral reefs near some of the islands have been heavily damaged by exploitation as raw materials for industrial ventures such as cement industries, brick manufacture, masonry work and lime kilns. Though legal quarrying of the reefs is now stopped, up to 250 m³/day of reef were destroyed for many years.

Habitation

The islands are uninhabited except for Krusadai, Musal and Nallathanni islands where antipoaching sheds are operating. Along the coast near the park there are about 125 villages which support about 100,000 people who are mainly Marakeyars, a local community principally engaged in fishing.

Habitat degradation

Experts say that Vaan Island, one of the four islands of the Tuticorn group, has split in two and if immediate efforts are not taken then the island would soon vanish under the sea. Vaan Island, which is the southernmost of the 21 islands in the Gulf of Mannar, was initially spread across 16 hectares, but had shrunk alarmingly by around 10.3 hectares to its current 5.7 hectares in less than three decades. According to J K Patterson Edward, director of Suganthi Devadasan Marine Research Institute (SDMRI), Tuticorin,"Rampant coral mining by people of the fishing villages along the coast is the main cause of the devastation to the island. Coral mining was banned in 2005, but the damage had already been done." Two of the 21 islands have already submerged around a decade ago.

Visitor information

Glass-bottomed boats available at Mandapam cater to tourists visiting the area. Access to the islands is prohibited. The nearest railway stations are at Mandapam and Tuticorin.

Geography

Flora

Fauna

Habitation

Habitat degradation

Visitor information

See also

References

Further reading