Gulf of Mannar

Last updated

Gulf of Mannar
Locatie Golf van Mannar.PNG
Location of Gulf of Mannar within the Indian Ocean
India Tamil Nadu relief map.png
Red pog.svg
Gulf of Mannar
Location of Gulf of Mannar between India and Sri Lanka
Tamil Nadu topo deutsch mit Gebirgen.png
Location Tamil Nadu
Coordinates 8°28′N79°01′E / 8.47°N 79.02°E / 8.47; 79.02 Coordinates: 8°28′N79°01′E / 8.47°N 79.02°E / 8.47; 79.02
Basin  countries Sri Lanka, India
Max. length160 km (99 mi)
Max. width130–275 km (81–171 mi)
Surface area10,500 km2 (4,100 sq mi)
Average depth5.8 m (19 ft)
Max. depth1,335 m (4,380 ft)
References [1] [2]

The Gulf of Mannar ( /məˈnɑːr/ mə-NAR) is a large shallow bay forming part of the Laccadive Sea in the Indian Ocean with an average depth of 5.8 m (19 ft). [3] It lies between the west coast of Sri Lanka and the southeastern tip of India, in the Coromandel Coast region. The chain of low islands and reefs known as Adam's Bridge (aka Rama Sethu), which includes Mannar Island, separates the Gulf of Mannar from Palk Bay, which lies to the north between Sri Lanka and India. The Malvathu Oya (Malvathu River) of Sri Lanka and the estuaries of Thamirabarani River and Vaippar River of South India drain into the Gulf. [4] The dugong (sea cow) is found here.

Contents

Conservation

Marine sanctuary

Located on the southeastern tip of the subcontinent, the Gulf of Mannar is known to harbour over 3,600 species of flora and fauna, making it one of the richest coastal regions in Asia. 117 hard coral species have been recorded in the Gulf of Mannar. Sea turtles are frequent visitors to the gulf as are sharks, dugongs, and dolphins. However, the combined effects of 47 villages, with a total population of around 50,000 has meant that overharvesting of marine species has become a problem. The decline of fish populations has been accompanied with reducing numbers of pearl oyster, gorgonian coral, and acorn worm. Local fishermen rely on the reef to feed their families, but destructive fishing methods combined with the stress of pollution and coral mining have meant both nearshore and offshore catches have decreased. Endangered species include dolphins, dugongs, whales and sea cucumbers. [1]

In 1986, a group of 21 islets lying off the Tamil Nadu coast between Thoothukudi and Dhanushkodi was declared the Gulf of Mannar Marine National Park. The park and its 10 km buffer zone were declared a Biosphere Reserve in 1989.

Biosphere reserve

The Gulf of Mannar Biosphere Reserve covers an area of 10,500 km2 of ocean, 21 islands and the adjoining coastline. The islets and coastal buffer zone include beaches, estuaries, and tropical dry broadleaf forests, while the marine environments include seaweed communities, sea grass communities, coral reefs, salt marshes and mangrove forests. [5] May 2019, The National Centre for Coastal Research, an institute under the Ministry of Earth Sciences, in India, has a field research station in the Gulf of Mannar region, have found an alarming pattern of bleaching in the reefs in Mandapam, Kilakarai and Palk Bay. Researchers observed a pattern of bleaching in corals when the temperatures rose to between 32 °C and 36 °C. [6]

Marine activities

Pearl fishing in the Gulf of Mannar, c. 1926 Pearling crew 1926.JPG
Pearl fishing in the Gulf of Mannar, c. 1926

The Gulf of Mannar is known for its pearl banks of Pinctada radiata and Pinctada fucata for at least two thousand years. Pliny the Elder (23–79) praised the pearl fishery of the gulf as one of the most productive in the world. [7] [8] [9] Although extraction of natural pearls is considered too expensive in most parts of the world, it is still carried out in the gulf. [10]

The chief seaports on the Gulf of Mannar are Colombo in Sri Lanka and Thoothukudi (Tuticorin) in Tamil Nadu. While these ports can accommodate deep-draft vessels, the shallow Palk Strait can only accommodate small shallow-draft vessels. In July 2005, the Indian Government took preliminary steps to go ahead with the Sethusamudram Shipping Canal Project, which would create a deep channel linking the Gulf of Mannar to the Bay of Bengal. Project boosters emphasize the benefits of a direct shipping route that connects India's east and west coasts without the long trip around Sri Lanka; environmentalists have warned against the grave damage such a project could cause to the sea life and fisheries of the Palk Strait and the Gulf.

See also

Related Research Articles

Bay of Bengal Northeastern part of the Indian Ocean

The Bay of Bengal is the northeastern part of the Indian Ocean, bounded on the west and northwest by India, on the north by Bangladesh, and on the east by Myanmar and the Andaman and Nicobar Islands of India. Its southern limit is a line between Sangaman Kanda, Sri Lanka and the north westernmost point of Sumatra (Indonesia). It is the largest water region called a bay in the world. There are countries dependent on the Bay of Bengal in South Asia and Southeast Asia. In ancient Classical India, the Bay of Bengal was known as Kalinga Sagar. Later during the British India, it came forth as the Bay of Bengal after the historic Bengal region, as the Port of Kolkata served as the gateway to the Crown rule in India. Cox's Bazar, the longest sea beach in the world and Sundarbans, the largest mangrove forest and the natural habitat of the Bengal tiger, are located along the bay.

Gulf of Thailand A shallow inlet in the western part of the South China Sea

The Gulf of Thailand, also known as the Gulf of Siam, is a shallow inlet in the southwestern South China Sea, bounded between the southwestern shores of the Indochinese Peninsula and the northern half of the Malay Peninsula. It is around 800 km (500 mi) in length and up to 560 km (350 mi) in width, and has a surface area of 320,000 km2 (120,000 sq mi). The gulf is surrounded on the north, west and southwest by the coastlines of Thailand, on the northeast by Cambodia and the Mekong Delta region of Vietnam, and opens to the South China Sea in the southeast.

Adams Bridge Landform off coast of Sri Lanka

Adam's Bridge, also known as Rama's Bridge or Rama Setu, is a chain of natural limestone shoals, between Pamban Island, also known as Rameswaram Island, off the south-eastern coast of Tamil Nadu, India, and Mannar Island, off the north-western coast of Sri Lanka. Geological evidence suggests that this bridge is a former land connection between India and Sri Lanka.

Palk Strait Strait between Tamil Nadu, India and Sri Lanka

The Palk Strait is a strait between the Tamil Nadu state of India and the Jaffna District of the Northern Province of the island nation of Sri Lanka. It connects the Bay of Bengal in the northeast with Palk Bay in the southwest. With a minimum depth of less than 9.1 m, it is 40 to 85 miles wide and 85 miles long. Several rivers flow into it, including the Vaigai River of Tamil Nadu. The strait is named after Robert Palk, who was a governor of Madras (1755–1763) during the Company Raj period.

Thoothukudi City in Tamil Nadu in India

Thoothukudi, 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 headquarters of Thoothukudi district. It is located about 590 kilometres southwest of Chennai, 190 kilometres northeast of Thiruvananthapuram and 580 kilometres southeast of Bengaluru. According to Confederation of Indian Industry, Thoothukudi has the second highest Human Development Index in Tamil Nadu next to Chennai. Thoothukudi City serves as the headquarters of Tamilnad Mercantile Bank Limited. Major educational establishments in the city include Government Thoothukudi Medical College, Fisheries College and Research Institute, Tamil Nadu Maritime Academy, V.O. Chidambaram College, Kamaraj College, Anna University and Government Polytechnic College. V. O. Chidambaranar Port Trust is one of the fastest growing Major Ports in India. Thoothukudi is an "Emerging Energy and Industrial hub of South India".

Sethusamudram Shipping Canal Project Canal between India and Sri Lanka

Sethusamudram Shipping Canal Project is a proposed project to create a shipping route in the shallow straits between India and Sri Lanka. This would provide a continuously navigable sea route around the Indian Peninsula. The channel would be dredged in the Sethusamudram sea between Tamil Nadu and Sri Lanka, passing through the limestone shoals of Rama's Bridge.

Laccadive Sea A body of water bordering India, the Maldives, and Sri Lanka.

The Laccadive Sea or Lakshadweep Sea is a body of water bordering India, the Maldives, and Sri Lanka. It is located to the southwest of Karnataka, to the west of Kerala and to the south of Tamil Nadu. This warm sea has a stable water temperature through the year and is rich in marine life, the Gulf of Mannar alone hosting about 3,600 species. Mangaluru, Kannur, Kozhikode, Ponnani, Kochi, Alappuzha, Kollam, Thiruvananthapuram, Tuticorin, Colombo, and Malé are the major cities on the shore of the Laccadive Sea. Kanyakumari, the southernmost tip of peninsular India, also borders this sea.

Palk Bay

Palk Bay is a semi-enclosed shallow water body with a water depth maximum of 13 m. It is located between the southeast coast of India and Sri Lanka. Palk Bay is located between 8° 50′ and 10° North latitudes and 78° 50′ and 80° 30′ East longitudes. The width of Palk Bay ranges from 57 to 107 km and the length is around 150 km. Palk Bay is considered to be one amongst the major sinks for sediments along with Gulf of Mannar. Sediments discharged by rivers and transported by the surf currents as littoral drift settle in this sink. Few scientists have tried to understand the wave characteristics within the Palk Bay.

Gulf of Mannar Marine National Park

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, India for 160 km between Thoothukudi (Tuticorin) and Dhanushkodi. It is the core area of the Gulf of Mannar Biosphere Reserve which includes a 10 km buffer zone around the park, including the populated coastal area. The park has a high diversity of plants and animals in its marine, intertidal and near shore habitats. Public access inside the park is limited to glass-bottom boat rides.

Ramanathapuram district District of Tamil Nadu in India district

Ramanathapuram District, also known as Ramnad District, is one of the 38 districts an administrative districts of Tamil Nadu state in southern India. The old Ramanathapuram District consists of Present day Virudhunagar and Sivagangai districts, it touches the Western ghats and bordered with the state of Kerala and east by Bay of bengal. It was the largest district on that time. The town of Ramanathapuram is the district headquarters. Ramanthapuram District has an area of 4,123 km2. It is bounded on the north by Sivaganga District, on the northeast by Pudukkottai District, on the east by the Palk Strait, on the south by the Gulf of Mannar, on the west by Thoothukudi District, and on the northwest by Virudhunagar District. The district contains the Pamban Bridge, an east-west chain of low islands and shallow reefs that extend between India and the island nation of Sri Lanka, and separate the Palk Strait from the Gulf of Mannar. The Palk Strait is navigable only by shallow-draft vessels. As of 2011, Ramanathapuram district had a population of 1,353,445 with a sex-ratio of 983 females for every 1,000 males.

Environment of Sri Lanka

The environment of Sri Lanka is unique in being one of the world's bio-diversity hot-spots.

Bar Reef

The Bar Reef is a system of coral reefs just offshore from Sri Lanka's Kalpitiya peninsula. It has the greatest biodiversity of any coral reef in the waters around India and is one of the few pristine coral reef systems in Sri Lanka.

Marine National Park, Gulf of Kutch National Park situated on the southern shore of the Gulf of Kutch in the Devbhumi Dwarka district of Gujarat state, India.

Marine National Park in the Gulf of Kutch is situated on the southern shore of the Gulf of Kutch in the Devbhumi Dwarka district of Gujarat state, India. In 1980, an area of 270 km2 from Okha to Jodiya was declared Marine Sanctuary. Later, in 1982, a core area of 110 km2 was declared Marine National Park under the provisions of the Wildlife (protection) Act, 1972 of India. There are 42 islands on the Jamnagar coast in the Marine National Park, most of them surrounded by reefs. The best known island is Pirotan.

Marakkar/Maricar/Marecar/Marikkar/Marican/Marecan (Sinhalese: Marakkala), is a South Asian Muslim community found in parts of Indian states of Tamil Nadu, Kerala and in Sri Lanka. The Marakkars speak Tamil in Tamil Nadu and Sri Lanka and Malayalam in Kerala. The community trace their ancestry to marriages between early Arab Muslim traders of the high seas and indigenous Mukkuvar coastal women. Arab traders have also married with other non-Mukkuvar South Asian women in Sri Lanka and India, but their descendants are not necessarily members of the Marakkar community.

Hikkaduwa National Park

Hikkaduwa National Park is one of the three marine national parks in Sri Lanka. The national park contains a fringing coral reef of high degree of biodiversity. The area was declared a wildlife sanctuary on May 18, 1979, and then on August 14, 1988, upgraded to a nature reserve with extended land area. The growth of the number of visitors in the next 25 years increased the degradation of the coral reef. To reduce the effects to the ecosystem, the reef was declared a national park on September 19, 2002.

1964 Rameswaram cyclone

The 1964 Rameswaram cyclone was regarded as one of the most powerful storms to ever strike India on record. The system was first identified as an area of low pressure over the Andaman Sea on December 15. Following interaction with a tropical wave, it began to develop and became a depression by December 18. Increasingly rapid intensification ensued over the following days with the cyclone attaining hurricane-force winds around 5°N the next day. Early on December 23, the storm struck Ceylon near Trincomalee with winds estimated at 240 km/h (150 mph), ranking it as a modern-day super cyclonic storm. Weakening somewhat, the storm soon struck Tamil Nadu. Rapid weakening followed once the cyclone was onshore and it degenerated into a depression on December 24 as it emerged over the Arabian Sea. The system later dissipated on December 26 over open water.

Devipattinam Village/Census Town in Tamil Nadu, India

Devipattinam is a coastal village of Ramanathapuram district., Tamil Nadu, India.

Coral reefs in India

Coral reefs in India are one of the most ancient and dynamic ecosystems of India. The coral reefs not only provide a sanctuary to a myriad of marine life but also play a key role in protecting the coastline from erosion. India has about 7517 km of coastline including islands but mainland coast is 6100 km.

The coastline of Tamil Nadu is located on the southeast coast of Indian Peninsula, and forms a part of Coromandel Coast of Bay of Bengal and Indian Ocean. It is 1076km long and is the second-longest coastline in the country after Gujarat. Chennai, the capital of the state and an important commercial and industrial center in the country is located in the northern part of the coast with Kanniyakumari, forming the southern tip where Indian Ocean, Bay of Bengal and Arabian Sea meet. It also shares maritime border with Sri Lanka across the Palk strait in Gulf of Mannar. The coastal corridor consists of 13 districts with 15 major ports and harbors, sandy beaches, lakes and river estuaries. Tamil Nadu is the only state in India with territory on the both the eastern and western coastlines.

Adams Bridge Marine National Park National Park in Sri Lanka

Adam's Bridge Marine National Park is a national park surrounding Adam's Bridge in northern Sri Lanka, approximately 30 km (19 mi) north west of Mannar.

References

  1. 1 2 J. Sacratees, R. Karthigarani (2008). Environment impact assessment. APH Publishing. p. 10. ISBN   978-81-313-0407-5.
  2. Gulf of Mannar, Great Soviet Encyclopedia (in Russian)
  3. Gulf of Mannar (SE India), Sea-Seek.
  4. Kallidaikurichi Aiyah Nilakanta Sastri. (1979). South India and South-East Asia: studies in their history and culture. Geetha Book House.
  5. UNDP Project brief: "Conserve and Sustainable-use of the Gulf of Mannar Biosphere Reserve's Coastal Biodiversity", New York, 1994 UNDP Project Brief Archived 16 June 2007 at the Wayback Machine
  6. https://www.thehindu.com/sci-tech/energy-and-environment/coral-bleaching-observed-near-mandapam-keezhakkarai-palk-bay/article27206124.ece
  7. R. Raghu Prasad and P. V. Ramachandran Nair (1973). "India and the Indian Ocean Fisheries" (PDF). Journal of the Marine Biological Association of India. 15: 1–19.
  8. Arnold Wright (1999). Twentieth century impressions of Ceylon: its history, people, commerce, industries, and resources. p. 227. ISBN   81-206-1335-X.
  9. James Hornell (2009). The Indian Pearl Fisheries of the Gulf of Manar and Palk Bay. BiblioBazaar. p. 6. ISBN   978-1-110-87096-7.
  10. Michael O'Donoghue (2006). Gems: their sources, descriptions and identification. Butterworth-Heinemann. p. 566. ISBN   0-7506-5856-8.