Puneet Varma (Editor)

Bay of Bengal

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Location  South Asia
Primary inflows  Indian Ocean
Max. width  1,610 km (1,000 mi)
Primary inflow  Indian Ocean
Type  Bay
Max. length  2,090 km (1,300 mi)
Area  2.172 million km²
Bay of Bengal httpsuploadwikimediaorgwikipediacommonsthu

Surface area  2,172,000 km (839,000 sq mi)
Basin countries  India, Bangladesh, Indonesia, Myanmar (Burma), Sri Lanka

Digha bay of bengal india s low cost tourist place

The Bay of Bengal, the largest bay in the world, forms the northeastern part of the Indian Ocean. Roughly triangular, it is bordered mostly by India and Sri Lanka to the west, Bangladesh to the north, and Myanmar (Burma) and the Andaman and Nicobar Islands (India) to the east.


Map of Bay of Bengal

The Bay of Bengal occupies an area of 2,172,000 square kilometres (839,000 sq mi). A number of large rivers – the Ganges and its tributaries such as the Padma and Hooghly, the Brahmaputra and its tributaries such as the Jamuna and Meghna, other rivers such as the Irrawaddy River, Godavari, Mahanadi, Krishna and Kaveri flow into the Bay of Bengal. Among the important ports are Chennai, Chittagong, Kolkata, Mongla, Paradip, Tuticorin, Visakhapatnam and Yangon.


The International Hydrographic Organization defines the limits of the Bay of Bengal as follows:


In ancient Hindu scriptures, this water body is referred to as 'Mahodadhi' (Sanskrit: महोदधि, lit. great water receptacle) while it appears as Sinus Gangeticus or Gangeticus Sinus, meaning "Gulf of the Ganges", in ancient maps.

The other Sanskrit names for Bay of Bengal are 'Vangopasagara' (Sanskrit: वङ्गोपसागर, lit. Bengal's Bay), also simply called as 'Vangasagara' (Sanskrit: वङ्गसागर, lit. Bengal Sea) and 'Purvapayodhi' (Sanskrit: पूर्वपयोधि, lit. Eastern Ocean). Even today in Bengali, it is known as 'Bangopasaagar'.


Many major rivers of the Indian subcontinent flow west to east before draining into the Bay of Bengal. The Ganga is the northernmost of these. Its main channel enters and flows through Bangladesh, where it is known as the Padma River, before joining the Meghna River. However, the Brahmaputra River flows from east to west in Assam before turning south and entering Bangladesh where it is called the Jamuna River. This joins the Padma whereupon the Padma joins the Meghna River that finally drains into Bay of Bengal. The Sundarbans mangrove forest at the delta of the Ganges, Brahmaputra and Meghna rivers lies partly in West Bengal and partly in Bangladesh. The Brahmaputra at 2,948 km (1,832 mi) is the 28th longest River in the world. It originates in Tibet. The Hooghly River, another channel of the Ganga that flows through Calcutta drains into Bay of Bengal in India itself.

The Ganga–Brahmaputra rivers deposits nearly 1000 million tons of sediment per year. The sediment from these two rivers forms the Bengal Delta and the submarine fan, a vast structure that extends from Bangladesh to south of the Equator, is up to 16.5 kilometres (10.3 mi) thick, and contains at least 1,130 trillion tonnes of sediment, which has accumulated over the last 17 million years at an average rate of 665 million tons per annum. The Bay of Bengal used to be deeper than the Mariana Trench, the present deepest ocean point. The fan has buried organic carbon at a rate of nearly 1.1 trillion mol/yr since the early Miocene period. The two rivers currently contribute nearly 8% of the total organic carbon (TOC) deposited in the world's oceans. Due to high TOC accumulation in the deep sea bed of the Bay of Bengal, the area is rich in oil and natural gas and gas hydrate reserves. Bangladesh can reclaim land substantially and economically from the sea area by constructing sea dikes, bunds, causeways and by trapping the sediment from its rivers.

Further south of Bengal, the Mahanadi, Godavari, Krishna and Kaveri Rivers are the major rivers that flow from west to east in the Indian subcontinent and drain into the Bay of Bengal. Many small rivers also drain directly into the Bay of Bengal; the shortest of them is the Cooum River at 64 km (40 mi).

The Irrawaddy (or Ayeyarwady) River in Myanmar flows into the Andaman Sea of the Bay of Bengal and once had thick mangrove forest of its own.


Some of the biggest ports in the world — Chennai, Visakhapatnam, Paradip, Kolkata in India as well as Chittagong and Mongla in Bangladesh — are on the bay.

Other Indian ports on the bay include Kakinada, Pondicherry, Dhamra, Gopalpur.


The islands in the bay are numerous, including the Andaman Islands, Nicobar and Mergui groups of India. The Cheduba group of islands, in the north-east, off the Burmese coast, are remarkable for a chain of mud volcanoes, which are occasionally active. Great Andaman is the main archipelago or island group of the Andaman Islands, whereas Ritchie's Archipelago consists of smaller islands. Only 37, or 6.5%, of the 572 islands and islets of the Andaman and Nicobar Islands are inhabited.


The Bay of Bengal is a salt water sea and is a part of the Indian Ocean.

Plate tectonics

The lithosphere of the earth is broken up into what are called tectonic plates. Underneath the Bay of Bengal is the Indian Plate which is part of the great Indo-Australian Plate and is slowly moving north east. This plate meets the Burma Microplate at the Sunda Trench. The Nicobar Islands, and the Andaman Islands are part of the Burma Microplate. The India Plate subducts beneath the Burma Plate at the Sunda Trench or Java Trench. Here, the pressure of the two plates on each other increase pressure and temperature resulting in the formation of volcanoes such as the volcanoes in Myanmar, and a volcanic arc called the Sunda Arc. The Sumatra-Andaman earthquake and Asian tsunami was a result of the pressure at this zone causing a submarine earthquake which then resulted in a destructive tsunami.

Marine geology

A zone 50 m wide extending from the island of Ceylon and the Coromandel coast to the head of the bay, and thence southwards through a strip embracing the Andaman and Nicobar islands, is bounded by the 100 fathom line of sea bottom; some 50 m. beyond this lies the 500-fathom limit. Opposite the mouth of the Ganges, however, the intervals between these depths are very much extended by deltaic influence.

Swatch of No Ground is a 14 km-wide deep sea canyon of the Bay of Bengal. The deepest recorded area of this valley is about 1340 m. The submarine canyon is part of the Bengal Fan, the largest submarine fan in the world.

Marine biology, flora and fauna

The Bay of Bengal is full of biological diversity, diverging amongst coral reefs, estuaries, fish spawning and nursery areas, and mangroves. The Bay of Bengal is one of the World's 64 largest marine ecosystems.

Kerilia jerdonii is a sea snake of the Bay of Bengal. Glory of Bengal cone (Conus bengalensis) is just one of the seashells which can be photographed along beaches of the Bay of Bengal. An endangered species, the olive ridley sea turtle can survive because of the nesting grounds made available at the Gahirmatha Marine Wildlife Sanctuary, Gahirmatha Beach, Odisha, India. Marlin, barracuda, skipjack tuna, (Katsuwonus pelamis), yellowfin tuna, Indo-Pacific humpbacked dolphin (Sousa chinensis), and Bryde's whale (Balaenoptera edeni) are a few of the marine animals. Bay of Bengal hogfish (Bodianus neilli) is a type of wrass which live in turbid lagoon reefs or shallow coastal reefs. Schools of dolphins can be seen, whether they are the bottle nose dolphin (Tursiops truncatus), pantropical spotted dolphin (Stenella attenuata) or the spinner dolphin (Stenella longirostris). Tuna and dolphins usually reside in the same waters. In shallower and warmer coastal waters the Irrawaddy dolphins (Orcaella brevirostris) can be found.

The Great Nicobar Biosphere Reserve provides sanctuary to many animals some of which include the saltwater crocodile (Crocodylus porosus), giant leatherback sea turtle (Dermochelys coriacea), and Malayan box turtle (Cuora amboinensis kamaroma) to name a few.

Another endangered species royal Bengal tiger is supported by Sundarbans a large estuarine delta that holds a mangrove area in the Ganges River Delta.

Chemical oceanography

Coastal regions bordering the Bay of Bengal are rich in minerals. Sri Lanka, Serendib, or Ratna – Dweepa which means Gem Island. Amethyst, beryl, ruby, sapphire, topaz, and garnet are just some of the gems of Sri Lanka. Garnet and other precious gems are also found in abundance in the Indian states of Odisha and Andhra Pradesh.

Physical oceanography – climate

From January to October, the current is northward flowing, and the clockwise circulation pattern is called the "East Indian Current". The Bay of Bengal monsoon moves in a northwest direction striking the Nicobar Islands, and the Andaman Islands first end of May, then the north eastern coast of India by end of June.

The remainder of the year, the counterclockwise current is southwestward flowing, and the circulation pattern is called the East Indian Winter Jet. September and December see very active weather, season varsha (or monsoon), in the Bay of Bengal producing severe cyclones which affect eastern India. Several efforts have been initiated to cope with storm surge.

Tropical storms and cyclones

A tropical storm with rotating winds blowing at speeds of 74 miles (119 kilometres) per hour is called a cyclone when they originate over the Bay of Bengal; and called a hurricane in the Atlantic. Between 100,000 and 500,000 residents of Bangladesh were killed because of the 1970 Bhola cyclone.

  • 2016, Cyclone Kyant
  • 2016, Cyclone Roanu
  • 2015, Cyclone Komen
  • 2014, Very Severe Cyclonic Storm Hudhud
  • 2013, Very Severe Cyclonic Storm Phailin
  • 2013, Cyclone Viyaru
  • 2012, Cyclone Nilam
  • 2011, Very Severe Cyclonic Storm Thane
  • 2010, Very Severe Cyclonic Storm Giri
  • 2009, Very Severe Cyclonic Strom Aila
  • 2008, Very Severe Cyclonic Storm Nargis
  • 2007, Very Severe Cyclonic Storm Sidr
  • 2006, Very Severe Cyclonic Storm Mala
  • 1999, Odisha Super Cyclonic Storm 05B
  • 1996, Konaseema Cyclone
  • 1991, Super Cyclonic Storm 02B
  • 1989, November Typhoon Gay
  • 1985, May Tropical Storm One (1B)
  • 1982, April Cyclone One (1B)
  • 1982, May Tropical Storm Two (2B)
  • 1982, October Tropical Storm Three (3B)
  • 1981, December Cyclone Three (3B)
  • 1980, October Tropical Storm One (1B)
  • 1980, December Unknown Storm Four (4B)
  • 1980, December Tropical Storm Five (5B)
  • 1977, Andhra Pradesh Cyclone (6B)
  • 1971, Cyclone Odisha
  • 1970, November Bhola cyclone
  • The Calcutta cyclone of 1864: caused a storm surge of 40 feet. Barometer 28.025 inches of mercury. 50,000 direct deaths and 30,000 from disease.
  • The Backergunge cyclone of 1876: 10 to 30 or 40 feet storm surge. 100,000 direct deaths and 100,000 indirect from disease.
  • The False Point cyclone of 1885: 22 feet of storm surge. Barometer 27.135 inches of mercury.
  • Historic sites

  • The ancient Buddhist heritage sites of Pavurallakonda, Thotlakonda and Bavikonda lie along the coast of Bay of Bengal at Visakhapatnam in India.
  • The remains of the Sri Vaisakheswara Swamy temple lie under the Bay of Bengal. Spokespeople from Andhra University Centre for Marine Archaeology say the temple may be opposite the Coastal Battery.
  • The Jagannath Temple at Puri is the one of the four sacred places in Hindu pilgrimage along with Puri beach on the banks of Bay of Bengal. Mahodadhi was named after Lord Jagannath.
  • Seven Pagodas of Mahabalipuram is the name for Mahabalipuram. Mahabalipuram's Shore Temple, a World Heritage Site was constructed in the 8th century AD and myth has it that six other temples were built here.
  • One site that has been preserved is Vivekanandar Illam. It was constructed in 1842 by the American "Ice King" Frederic Tudor to store and market ice year round. In 1897, Swami Vivekananda's famous lectures were recorded here at Castle Kernan. The site is an exhibition devoted to Swami Vivekananda and his legacy.
  • Arikamedu is an archaeological site in Southern India, in Kakkayanthope, Ariyankuppam Commune, Puducherry. It is 4 kilometres (2.5 mi) from the capital, Pondicherry of the Indian territory of Puducherry
  • Konark is the home of the Sun Temple or Black Pagoda. This Brahman sanctuary was built of black granite mid-1200 AD and has been declared a World Heritage Site.
  • Ramanathaswamy Temple is at Dhanushkodi, where the Bay of Bengal and the Laccadive sea come together.
  • Religious importance

    The Bay of Bengal in the stretch of Swargadwar , the gateway to heaven in Sanskrit , in the Indian town of Puri is considered holy by Hindus.

    The Samudra arati is a daily tradition started by the present Shankaracharya of Puri 9 years ago to honour the sacred sea. The daily practise includes prayer and fire offering to the sea at Swargadwar in Puri by disciples of the Govardhana matha of the Shankaracharya. On Paush Purnima of every year the Shankaracharya himself comes out to offer prayers to the sea.


    One of the first trading ventures along the Bay of Bengal was The Company of Merchants of London Trading into the East Indies more commonly referred to as British East India Company. Gopalpur-on-Sea was one of their main trading centers. Other trading companies along the Bay of Bengal shorelines were English East India Company and French East India Company.

    BIMSTEC Bay of Bengal Initiative for MultiSectoral Technical and Economic Cooperation (BIMSTEC) supports free trade internationally around the Bay of Bengal between Bangladesh, Bhutan, India, Myanmar, Nepal, Sri Lanka, and Thailand.

    The Sethusamudram Shipping Canal Project is a new venture proposed which would create a channel for a shipping route to link the Gulf of Mannar with the Bay of Bengal. This would connect India east to west without the necessity of going around Sri Lanka.

    Thoni and catamaran fishing boats of fishing villages thrive along the Bay of Bengal shorelines. Fishermen can catch between 26 and 44 species of marine fish. In one year, the average catch is two million tons of fish from the Bay of Bengal alone. Approximately 31% of the world’s coastal fishermen live and work on the bay.

    Strategic importance

    The Bay of Bengal is centrally located in the region from the Middle East to the Philippine Sea. Even from aviations strategic aerial position it lies at the centre. It lies at dead center of two huge economic blocks, the SAARC and ASEAN. It influences China's southern landlocked region in the north and major sea ports of Bangladesh and India. Bangladesh, China and India have forged naval cooperation agreements with Malaysia, Thailand and Indonesia to increase cooperation in checking terrorism in the high seas.

    The Bay of Bengal is strategically crucial for India. It is a natural extension of its sphere of influence. Its outlying islands (the Andaman and Nicobar islands) and, most importantly, major ports such as Kolkata, Chennai, Visakhapatnam, and Tuticorin along its coast with the Bay of Bengal added to its importance.

    China has recently made efforts to project influence into the region through tie-ups with Myanmar and Bangladesh. The United States has held major exercises with Bangladesh, India, Malaysia, Singapore and Thailand. The largest ever wargame in Bay of Bengal, known as Malabar 2007, was held in 2007 and naval warships from US, Singapore, Japan and Australia took part. India was a participant.

    Large deposits of natural gas incited a serious up-for-grabs urgency by India. Disputes over rights of some oil and gas blocks have caused brief diplomatic spats between Myanmar and India with Bangladesh.

    The disputed maritime boundary between Bangladesh and Myanmar resulted in military tensions in 2008 and 2009. Bangladesh is pursuing a settlement with Myanmar and India to the boundary dispute through the International Tribunal on the Law of the Sea.

    It has been argued that the conceptual division of the Bay of Bengal region between South Asia and Southeast Asia may no longer be appropriate and that the rise of India as a major power may lead to a new mental mapping of the Bay of Bengal as a coherent strategic region.


    The Asian brown cloud, a layer of air pollution that covers much of South Asia and the Indian Ocean every year between January and March, and possibly also during earlier and later months, hangs over the Bay of Bengal. It is considered to be a combination of vehicle exhaust, smoke from cooking fires, and industrial discharges.

    Transboundary issues affecting the marine ecosystem

    A transboundary issue is defined as an environmental problem in which either the cause of the problem and/or its impact is separated by a national boundary; or the problem contributes to a global environmental problem and finding regional solutions is considered to be a global environmental benefit. The eight Bay of Bengal countries have (2012) identified three major transboundary problems (or areas of concern) affecting the health of the Bay, that they can work on together. With the support of the Bay Of Bengal Large Marine Ecosystem Project (BOBLME), the eight countries are now (2012) developing responses to these issues and their causes, for future implementation as the Strategic Action Programme.

    Overexploitation of fisheries

    Fisheries production in the Bay of Bengal is six million tonnes per year, more than seven percent of the world's catch. The major transboundary issues relating to shared fisheries are: a decline in the overall availability of fish resources; changes in species composition of catches; the high proportion of juvenile fish in the catch; and changes in marine biodiversity, especially through loss of vulnerable and endangered species. The transboundary nature of these issues are: that many fish stocks are shared between BOBLME countries through the transboundary migration of fish, or larvae. Fishing overlaps national jurisdictions, both legally and illegally – overcapacity and overfishing in one location forces a migration of fishers and vessels to other locations. All countries (to a greater or lesser degree) are experiencing difficulties in implementing fisheries management, especially the ecosystem approach to fisheries. Bay of Bengal countries contribute significantly to the global problem of loss of vulnerable and endangered species.

    The main causes of the issues are: open access to fishing grounds; Government emphasis on increasing fish catches; inappropriate government subsidies provided to fishers; increasing fishing effort, especially from trawlers and purse seiners; high consumer demand for fish, including for seed and fishmeal for aquaculture; ineffective fisheries management; and illegal and destructive fishing.

    Degradation of critical habitats

    The Bay of Bengal is an area of high biodiversity, with many endangered and vulnerable species. The major transboundary issues relating to habitats are: the loss and degradation of mangrove habitats; degradation of coral reefs; and the loss of, and damage to, seagrasses. The transboundary nature of these major issues are: that all three critical habitats occur in all BOBLME countries. Coastal development for several varying uses of the land and sea are common in all BOBLME countries. Trade in products from all the habitats is transboundary in nature. Climate change impacts are shared by all BOBLME countries. The main causes of the issues are: food security needs of the coastal poor; lack of coastal development plans; increasing trade in products from coastal habitats; coastal development and industrialization; ineffective marine protected areas and lack of enforcement; upstream development that affects water-flow; intensive upstream agricultural practices; and increasing tourism.

    Pollution and water quality

    The major transboundary issues relating to pollution and water quality are: sewage-borne pathogens and organic load; solid waste/marine litter; increasing nutrient inputs; oil pollution; persistent organic pollutants (POPs) and persistent toxic substances (PTSs); sedimentation; and heavy metals. The transboundary nature of these issues are: discharge of untreated/partially treated sewage being a common problem. Sewage and organic discharges from the Ganges-Brahmaputra-Meghna River are likely to be transboundary. Plastics and derelict fishing gear can be transported long distances across national boundaries. High nutrient discharges from rivers could intensify largescale hypoxia. Atmospheric transport of nutrients is inherently transboundary. Differences between countries with regard to regulation and enforcement of shipping discharges may drive discharges across boundaries. Tar balls are transported long distances. POPs/PTSs and mercury, including organo-mercury, undergo long-range transport. Sedimentation and most heavy metal contamination tend to be localized and lack a strong transboundary dimension. The main causes of the issues are: increasing coastal population density and urbanization; higher consumption, resulting in more waste generated per person; insufficient funds allocated to waste management; migration of industry into BOBLME countries; and proliferation of small industries.


    Northern Circars occupied the western coast of the Bay of Bengal and is now considered to be India's Madras state. Chola dynasty (9th century to 12th century) when ruled by Rajaraja Chola I occupied the western coastline of the Bay of Bengal circa AD 1014, The Bay of Bengal was also called as the Chola Lake. The Kakatiya dynasty reached the western coastline of the Bay of Bengal between the Godavari and the Krishna rivers. Kushanas about the middle of the 1st century AD invaded northern India perhaps extending as far as the Bay of Bengal. Chandragupta Maurya extended the Maurya Dynasty across northern India to the Bay of Bengal. Hajipur was a stronghold of Portuguese Pirates. In the 16th century the Portuguese built trading posts in the north of the Bay of Bengal at Chittagong (Porto Grande) and Satgaon (Porto Pequeno). Before the arrival of British to India it was also known as "Kalinga Sagar".

    British penal colony

    Cellular Jail or "Black Waters" built in 1896 on Ross Island, a part of the Andaman Island Chain. As early as 1858 this island was used as a British penal colony for political prisoners facing life imprisonment.

    Marine archaeology

    Maritime archaeology or marine archaeology is the study of material remains of ancient peoples. A specialized branch, Archaeology of shipwrecks studies the salvaged artifacts of ancient ships. Stone anchors, amphorae shards, elephant tusks, hippopotamus teeth, ceramic pottery, a rare wood mast and lead ingots are examples which may survive the test of time for archaeologists to study and place the salvaged findings into a time line of history. coral reefs, tsunamis, cyclones, mangrove swamps, battles and a criss cross of sea routes in a high trading area combined with pirating have all contributed to shipwrecks in the Bay of Bengal.

    Famous ships and shipwrecks

  • 1778 to 1783 The Naval operations in the American Revolutionary War or American War of Independence ranged as far as the Bay of Bengal.
  • c. 1816 Mornington ship burned in the Bay of Bengal.
  • 1850 American clipper brig Eagle is supposed to have sunk in the Bay of Bengal.
  • American Baptist missionary Adoniram Judson, Jr. died 12 April 1850 and was buried at sea in the Bay of Bengal.
  • 1855 The Bark "Incredible" struck on a sunken rock in the Bay of Bengal.
  • 1865, a gale dismasted the Euterpe while traversing the Bay of Bengal typhoon.
  • 1875 Veleda 76 m (250 ft) long and 15 m (50 ft) wide is a part of a current salvage operation.
  • 1942 Japanese cruiser Yura of the Second Expeditionary Fleet, Malay Force attacked merchant ships in the Bay of Bengal.
  • 1971 December 3 – It was claimed that Indian Navy destroyer INS Rajput sunk the Pakistan Navy submarine PNS Ghazi off Visakhapatnam, in the Bay of Bengal.
  • References

    Bay of Bengal Wikipedia