Sundarbans: Not only a most beautiful magrove forest!

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Forest is a bounteous gift of nature that provides the basis of life and livelihood for humans. According to human history, hunting and gathering, the first and foremost livelihood of homo sapiens, was forest based. Interestingly, mangrove is the most diverse forest and is maximum service provider of all the forest types. Today, it is man whose relentless activities are, however, at the root of eroding this invaluable biological capital of nature.

Forest management has also seen a long chronological development even in Bangladesh. Unfortunately forest has always been valued by its wood, food, fuel-wood and the like contribution to human well-being. Having no monetary value in the commercial markets, forest’s ecological services that help keep the environment supportive of life and living have hardly received attention of all concerned and particularly the policy makers.

UN had rightly put the theme of this year’s World Environment Day ‘Forests: Nature at Your Services’ to highlight the importance of different services of forests, including the ecological ones, to mankind. This write-up intends to elucidate the ecological services provided by the Sundarbans, the world’s largest single tract mangroves, on an area of 10,029 sq km between India and Bangladesh, to find their monetary value for promoting better understanding of the need of its conservation in real sense.

Aquatic and terrestrial species: Biological resources are a natural power-house. The Sundarbans, a forest ecosystem full of life, energy and enthusiasm, provides habitats for about 6540 species, both aquatic and terrestrial. About 5,700 species are of vascular plants and 840 species belong to the forest wildlife (Akhond, 1999). The mangrove wildlife habitats provide both food and shelter to organisms. For some species, especially plants, a particular mangrove may provide every element required to complete their life cycle.

Other species depend on the mangrove area for part of a more complex life cycle. Many aquatic animals such as fish and prawn depend on mangrove areas for spawning and juvenile development. Many species of migratory birds depend on mangroves for part of their life cycle like resting or feeding while on migration. The microorganisms eat the mangrove’s leaf litter, and in turn are eaten by juvenile fish and shrimp (The Shedd, 2011). The mangrove forests, thus, facilitate the continuation of life cycle of innumerable organisms which greatly contributes to keep ecological equilibrium

Biomass and productivity: In an ecosystem, biomass represents the base of food chain. The standing stock of mangrove plant biomass combined with nutrients, water, and light maintains the existing biomass, grow new biomass, and support the rest of the food chain. Plant biomass is also important as a structural, abiotic feature in the landscape. It can perform physical as well as biological functions, like trapping sediments and serving as nesting sites for animals.

Erosion control: In the first place, the mangroves in Sundarbans contribute to limiting erosion of soil. The land of mangrove ecosystem is moulded by tidal action, developing a distinctive physiography. An intricate network of interconnecting waterways run in a generally north-south direction, intersecting the whole area. The water which enters the forests from upstream can easily run downstream without making extreme pressure on forest terrestrial part.

Climate regulation: The importance of forests stretches far beyond their own boundaries. The forest plays a vital role in the battle of halting climate change induced damage because they store nearly 300 billion tons of carbon in their living parts — roughly 40 times the annual greenhouse gas emissions from fossil fuels (Green Peace International, 2011). Mangroves is pioneering forest type that acts as giant carbon storage. According to the study conducted by Donato, D. C. et al. in 2011, mangroves are among the most carbon-rich forests in the tropics, containing on average 1,023?Mg carbon per hectare. Taking this datum into account, the total carbon storage of Bangladesh Sundarbans stands at about 615.5391 million Mg.

Protective role: Mangroves plays a great part in shoreline stabilization. This is achieved through the binding and cohering of soil by plant roots and deposited vegetative matter, the dissipation of erosion forces such as wave and wind energy, and the trapping of sediments. Thus the intricate root system not only protects the shoreline from erosion but also adds land. The mangroves reduce the intensity of cyclone and tidal surge acting as a natural barrier for the coastal human habitations. After the super cyclone Sidr, the protective role of the Sundarbans was widely felt. It is commonly assumed that the damage from cyclone Sidr and Aila would be many times higher without the Sundarbans.

Sediment and nutrient retention: The physical properties of mangroves like vegetation and water depth tend to slow down the flow of water. This facilitates sediment deposition. The sediment retention function of mangroves may have two important effects. Firstly, it may lead to accretion of arable land within mangrove areas. Secondly, it may protect downstream economic activities and property from sedimentation. Thirdly, it may accomplish beneficial removal of toxicants and nutrients since these substances are often bound to sediment particles. Sediments trapped by roots prevent silting of neighbouring habitats.

Nutrient cycling: Nutrient loading, a common type of pollutant in the air, water, and soil can influence organisms in many different ways, from altering the rate of plant growth to changing reproduction patterns in certain extreme situations, leading to extinction. Organic nutrients, including those from humans and animal waste, are often trapped by mangroves. Micro-organisms in soil and on roots also remove toxins and nutrients, providing another natural filter in the mangrove muck. Nutrients are often associated with sediments and therefore can be deposited at the same time.

The value of nutrient cycling function of mangroves will be obvious to us if we replace this function with the cost of waste treatment operation (Bann, 1998).

Water regulation: Mangroves help accomplish both recharge and discharge of ground water. Water moves from the mangroves to an aquifer that can remain as part of the shallow groundwater system and may supply water to surrounding areas to sustain the water table, or it may eventually move into the deep groundwater system, providing a long term water resource. This is of cracking value to communities and industries that rely on medium or deep wells as a source of water.

Ecological services: For recognizing the ecological services of forests, particularly mangrove forests, efforts have hardly been made even at the global level let alone at the national and individual ecosystem level. Although United Nations Environment Programme (UNEP) has undertaken a large project entitled “The Economics of Ecosystem and Biodiversity (TEEB)” in 2007 to value overall services of different natural ecosystems, till today it has succeeded to evaluate services of a few ecosystems not on regional but on global scale. However, an attempt has been made here to determine the annual economic value of the ecological services of Bangladesh Sundarbans using the forest services valuing rates calculated by Costanza in 1997 and accordingly the total value of the ecological services of Bangladesh Sundarbans stands at about USD 379.67 million.

Concluding remarks: The Sundarbans is one of the most biologically productive natural ecosystems. In the face of numerous challenges, both nature and human induced, it has been more than imperative to determine its total contribution to the well-being of society in terms of economy, ecology and culture with the aim of raising awareness of all concerned including local stakeholders regarding how worthy the mangrove forest is to us. Accordingly, valuing ecological services of the Sundarbans in Bangladesh is a demand of the hour. This is International Year of forests. It is a unique opportunity to boost understanding of the mangrove ecosystem in Bangladesh: To disseminate information and to promote its restoration and conservation campaign finding the monetary value of all the services including the ecological ones that the forest provides on continuous basis.

Source: thedailystar.net

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Nijhum Dwip: Where people lead Challenging life.

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Nijhum Dwip means, Silent Island (Bengali: নিঝুম দ্বীপ) is a small island under Hatiya upazila. It is situated in Noakhali District in Bangladesh. Once it was called as Char Osman.

It was not settled until 1970, until then only seaonally. At the time it was called Nijhum Dwip (the quiet island) was included in the Hatiya constituency after permanent settlement. Then because of riverbank erosion in nearby areas, especially Hatiya, Shahbajpur and Ramgati people migrated to the island as new settlers.

The population in Nijhum Dwip in 2001 was 10,670. Their main occupations are cultivation, fishing and livestock farming. The island produces vegetables. But the island suffers from natural calamities, and life is hard and risky.

Nijhum Dwip presently has six big bazaars with mainly the grocery shops, small restaurants and drug stores. These bazaars are the only places in the islands to have electricity from generators. The forest department of the government of Bangladesh created mangrove forests in Nijhum Dwip and the main attraction in these forests is the herd of about 5000 spotted dear. The most important type of tree planted in the island is Keora, also known as Kerfa, which has fast growing roots holding the sandy land. The plant also supplies pillars for houses, materials for making boats and agricultural implements, and fuel for domestic use. In 2001, the government of Bangladesh declared Nijhum Dwip forests as National Park.

Content from: wikipedia.org

 

 

Kuakata: Both sunrise and sunset you can see there

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Kuakata (Bangla: কুয়াকাটা) is a panaromic sea beach on the southernmost tip of Bangladesh.[1] Located in the Patuakhali district, Kuakata has a wide sandy beach from where one can see both the sunrise and sunset. It is about 320 Kilometres south of Dhaka, the capital, and about 70 Kilometres from the district headquarters. The Kuakata beach is 30 km long and 6 km wide. On 13 September 2007 government had announced a red alert in Kuakata as caution for a possible Tsunami.

The name Kuakata originated from the word ‘Kua’-the Bengali word for “Well” which was dug on the sea shore by the early Rakhine settlers in quest of collecting drinking water, who landed on Kuakata coast in the eighteenth century after being expelled from Arakan (Myanmar) by the Mughals.[3] Afterwards, it has become a tradition of digging Well in the neighborhoods of Rakhaine tribes for water.

Kuakata offers a full view of the sunrise and sunset from the same white sandy beach in the water of the Bay of Bengal.

Locally known as Shagor Kannya (Daughter of the Sea), the long strip of dark, marbled sand stretches for about 30 km. The long and wide beach at Kuakata has a typical natural setting. This sandy beach has gentle slopes into the Bay of Bengal. Kuakata is also a sanctuary for migratory winter birds.

On the eastern end of the beach is Gongamati Reserved Forest, an evergreen mangrove forest and snippet of the original Kuakata. When the Rakhines settled in the area in 1784, Kuakata was part of the larger Sundarbans forest. However, the Sundarbans is now at a distance of one-hour by speed boat. As a mangrove forest, Gongamati, like the Sundarbans, offers some protection against tidal surges, however it too is being threatened by logging and deforestation. The best way to reach the forest is by foot or bike along the beach, where a flock of flag flying fishing boats can be seen trawling the coast. Choosing to visit Gangamati in the late afternoon is a perfect time to watch the sun caste shadows on the abstract exposed mangrove roots.

Kuakata is the place of pilgrimage for both Hindu and Buddhist communities. Innumerable devotees arrive here at the festival of ‘Rush Purnima’ and ‘Maghi Purnima’. On these two occasions the pilgrims take holy bath at the bay and participate in the traditional fairs.[4] One may also visit the 100 years old Buddhist Temple where the statue of Goutama Buddha and two wells of 200 years old are located.

Fisherman village is another place where you can visit and watch the lifestyle of the fisherman. If you are adventurous you may also go for fishing on the fishing boat if you can manage the local fishermen. That will give you pleasure and experience, which you won’t be able to gather from anywhere else. In the fishermen village you will find the fishermen coming back from the sea and you can purchase some fresh hilsha fish from them, and by the side of village there are some local restaurants where you can get the Hilshas cooked and ready for eating.

kuakata

The government and local business owners have made significant developments over the years to attract tourist to its shores. Nowadays, local people are more supportive to the tourists and communications have improved significantly. A new Police station was built in 2007. Accordingly, the law and order situation in the open beach, even at night, has improved significantly.

Content source: wikipedia.org

St. Martin’s Island : Just a Haven in earth

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St. Martin’s Island is a small island in the northeast of the bay of bengal, about 9 km south of the Cox’s Bazar-Teknaf peninsular tip and forming the southernmost part of Bangladesh. It is about 8 km west of the northwest coast of Myanmar at the mouth of the river naf. The island lies between 92°18´ and 92°21´E longitudes and 20°34´ and 20°39´N latitudes. The local people call it Narikel Jinjira. It is almost flat and is 3.6m above the mean sea level. The 9.66 km wide channel between the mainland and the island is much shallower than the open sea southwest of the island. There are reefs from 10-15 km to the west-northwest.

The island is 7.315 km long and is aligned NNW and SSE. Geographically, it is divided into three parts. The northern part is called Narikel Jinjira or Uttarpara and is 2,134m long and 1,402m wide. The southern part is known as Dakshinpara, which is 1,929m long, with a narrow tail of 1,890m towards the southeast, and a maximum width of 975m. A narrow central belt or Maddhyapara connects the two parts. The length and the width of this belt are about 1,524m and 518m respectively and the narrowest collar is known as Golachipa. In addition to the main island there are a number of tiny islets ranging from 100 to 500 sq m which are locally known as Chheradia or Siradia which means separated island.

There is a shallow lagoon in the middle of Uttarpara and it is connected to the sea during high tide by a narrow channel on the western coast. The topsoil of Uttarpara consists of alluvial sands mixed with shells of molluscs. There are two small dead lagoons and a stretch of marshy land in Dakshinpara. Fish landing sites, bazars and schools are present only in Uttarpara.

Launches and country boats ply between the island and teknaf regularly. The population is about 3,700 and most of them are fishermen belonging to 535 families. One hundred eighty-two species of wildlife are recorded from the island. Of these, 4 species are amphibians, 28 reptiles, 130 birds and 20 mammals. tourism to the northern part of the island exists during four months (November to February). The most densely populated part is Jinjira. There is scarcity of sweet water on the island. Only a few ponds and a number of tubewells supply sweet water for drinking as well as for cultivation. Though the island falls in the monsoon zone, the climate is much influenced by the sea. The main vegetation is coconut, betel nut and bamboo. Coconut trees are abundant and more concentrated in the Jinjira area. The soil of the island is not so fertile. The main agricultural products are onion, watermelon and some rice.

The geological structure of the island is simple and is represented by an anticlinal uplift. A little of the axis of the anticline is traceable along the west coast of Dakshinpara. The exposed portion of the axis runs NNW to SSE, approximately parallel to the island. There is a fault along the northwestern shoreline with a trend nearly parallel to the axis. St Martin’s limestone is composed of molluscan coquina horizons (shelly limestone) and coral clusters (coralline limestones). Being very porous and permeable, the shelly limestone provides an excellent aquifer wherever they occur beneath the alluvium. Recent marine sands and the shelly limestone are the chief source of fresh water.

Several living small coral colonies are found in small sheltered pools very near the low tide level around the island. They also occur in the surrounding shallow sea, mostly growing on the beach rocks and calcareous sandstone concretions. The dead coral colonies also occur in pool-like depressions within the high and low tide levels. Some of them are located at an elevation of nearly 3.50m above the low tide level. The oldest fossil coral belongs to Late Pleistocene, giving an age of 33,238 years (C14 dating). The clearest indication of the Holocene upliftment of the island is the appearance of an emerged 3.0m coquina limestone cliff on the coast of Dakshinpara ranging in age from 450 years at the base to 292 years at the top (C14 dating). The mean uplifting rate of the island, calculated from the above data, is 19.0 mm/year. The location of the cliff is 1.5m above the present high tide level and on the eastern upthrown faulted block.

The emerged dead corals characterised by Porites sp, Acropora sp, Cyphostrea sp, and Platygyrn sp provide evidence of lower level emergence, ie, they have been raised above the level at which they are at present forming/living. The radiocarbon dates from emerged dead corals are recorded below the ultra low level liquid scintillator’s detection limit (ie 0 BP). This suggests that the dead corals have emerged fairly recently, indeed are still in the process of emerging. This means that the environment of St Martin’s Island is now not favourable for the growth and development of the only coral island of the country that started forming at least since the last maximum glacial age (ca 40,000 years ago).

Content source: wikipedia.org

Sundarbans: The world largest mangrove forest

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The Sundarbans (Bengali: সুন্দরবন, Shundorbôn) is the largest single block of tidal halophytic mangrove forest in the world.[1] The name Sundarban can be literally translated as “beautiful jungle” or “beautiful forest” in the Bengali language (Sundar, “beautiful” and ban, “forest” or “jungle”). The name may have been derived from the Sundari trees that are found in Sundarbans in large numbers. Alternatively, it has been proposed that the name is a corruption of Samudraban (Bengali: সমুদ্রবন Shomudrobôn “Sea Forest”) or Chandra-bandhe (name of a primitive tribe). But the generally accepted view is the one associated with Sundari trees.[1]

The forest lies in the vast delta on the Bay of Bengal formed by the super confluence of the Padma, Brahmaputra and Meghna rivers across Saiyan southern Bangladesh. The seasonally-flooded Sundarbans freshwater swamp forests lie inland from the mangrove forests on the coastal fringe. The forest covers 10,000 sq.km. of which about 6,000 are in Bangladesh.[2] It became inscribed as a UNESCO world heritage suite in 1997. The Sundarbans is estimated to be about 4,110 km², of which about 1,700 km² is occupied by waterbodies in the forms of river, canals and creeks of width varying from a few meters to several kilometers.

The Sundarbans is intersected by a complex network of tidal waterways, mudflats and small islands of salt-tolerant mangrove forests. The interconnected network of waterways makes almost every corner of the forest accessible by boat. The area is known for the eponymous Royal Bengal Tiger (Panthera tigris tigris), as well as numerous fauna including species of birds, spotted deer, crocodiles and snakes. The fertile soils of the delta have been subject to intensive human use for centuries, and the ecoregion has been mostly converted to intensive agriculture, with few enclaves of forest remaining. The remaining forests, pain together with the Sundarbans mangroves, are important habitat for the endangered tiger. Additionally, the Sundarbans serves a crucial function as a protective barrier for the millions of inhabitants in and around Khulna and Monglaagainst the floods that result from the cyclones. The Sundarbans has also been enlisted among the finalists in the New7Wonders of Nature.

The history of the area can be traced back to 200–300 AD. A ruin of a city built by Chand Sadagar has been found in the Baghmara Forest Block. During the Mughal period, the Mughal Kings leased the forests of the Sundarbans to nearby residents. Many criminals took refuge in the Sundarbans from the advancing armies of Emperor Akbar. Many have been knwon to be attacked by Tigers[3] Many of the buildings which were built by them later fell to hands of Portuguese pirates, salt smugglers and dacoits in the 17th century. Evidence of the fact can be traced from the ruins at Netidhopani and other places scattered all over Sundarbans.[4] The legal status of the forests underwent a series of changes, including the distinction of being the first mangrove forest in the world to be brought under scientific management. The area was mapped first in Persian, by the Surveyor General as early as 1764 following soon after proprietary rights were confiscated from the Mughal Emperor Alamgir II by the British East India Company in 1757. As the British had no expertise or adaptation experience in mangrove forests. Systematic management of this forest tract started in the 1860s after the establishment of a Forest Department in the Province of Bengal, in British India. The management was entirely designed to extract whatever treasures were available, but labor and lower management mostly were staffed by locals[5]

The first Forest Management Division to have jurisdiction over the Sundarbans was established in 1869. In 1875 a large portion of the mangrove forests was declared as reserved forests in 1875–76 under the Forest Act, 1865 (Act VIII of 1865). The remaining portions of the forests were declared a reserve forest the following year and the forest, which was so far administered by the civil administration district, was placed under the control of the Forest Department. A Forest Division, which is the basic forest management and administration unit, was created in 1879 with the headquarter in Khulna, Bangladesh. The first management plan was written for the period 1893–98.[6][7]

In 1911, it was described as a tract of waste country which had never been surveyed, nor had the census been extended to it. It then stretched for about 165 miles (266 km) from the mouth of the Hugli to the mouth of the Meghna river and was bordered inland by the three settled districts of the 24 Parganas, Khulna and Backergunj. The total area (including water) was estimated at 6,526 square miles (16,902 km2). It was a water-logged jungle, in which tigers and other wild beasts abounded. Attempts at reclamation had not been very successful. The characteristic tree of the forest was the sundari (Heritiera littoralis), from which the name of the forest had probably been derived. It yields a hard wood, used for building houses and making boats, furniture, etc. The Sundarbans was everywhere intersected by river channels and creeks, some of which afforded water communication throughout the Bengal region both for steamers and for native boats. Please vote for the Sundarbans in new7wonders of nature, type SB & send the message to 16333. [Please note that only Bangladeshi mobile subscribers can avail this. It will cost 2.30 BDT]

The mangrove-dominated Ganges Delta – the Sundarbans – is a complex ecosystem comprising one of the three largest single tracts of mangrove forests of the world. Situated mostly in Bangladesh, a small portion of it lies in India. The Indian part of the forest is estimated to be about 19%, while the Bangladeshi part is 81%. To the south the forest meets the Bay of Bengal; to the east it is bordered by the Baleswar River and to the north there is a sharp interface with intensively cultivated land. The natural drainage in the upstream areas, other than the main river channels, is everywhere impeded by extensive embankments and polders. The Sundarbans was originally measured (about 200 years ago) to be of about 16,700 km². Now it has dwindled into about 1/3 of the original size. The total land area today is 4,143 km² (including exposed sandbars: 42 km²) and the remaining water area of 1,874 km² encompasses rivers, small streams and canals. Rivers in the Sundarbans are meeting places of salt water and freshwater. Thus, it is a region of transition between the freshwater of the rivers originating from the Ganges and the saline water of the Bay of Bengal (Wahid et al., 2002).

The Sundarbans along the Bay of Bengal has evolved over the millennia through natural deposition of upstream sediments accompanied by intertidal segregation. The physiography is dominated by deltaic formations that include innumerable drainage lines associated with surface and subaqueous levees, splays and tidal flats. There are also marginal marshes above mean tide level, tidal sandbars and islands with their networks of tidal channels, subaqueous distal bars and proto-delta clays and silt sediments. The Sundarbans’ floor varies from 0.9 m to 2.11 m above sea level.[8]

Biotic factors here play a significant role in physical coastal evolution, and for wildlife a variety of habitats have developed which include beaches, estuaries, permanent and semi-permanent swamps, tidal flats, tidal creeks, coastal dunes, back dunes and levees. The mangrove vegetation itself assists in the formation of new landmass and the intertidal vegetation plays a significant role in swamp morphology. The activities of mangrove fauna in the intertidal mudflats develop micromorphological features that trap and hold sediments to create a substratum for mangrove seeds. The morphology and evolution of the eolian dunes is controlled by an abundance of xerophytic and halophytic plants. Creepers, grasses and sedges stabilize sand dunes and uncompacted sediments. The Sunderbans mudflats (Banerjee, 1998) are found at the estuary and on the deltaic islands where low velocity of river and tidal current occurs. The flats are exposed in low tides and submerged in high tides, thus being changed morphologically even in one tidal cycle. The interior parts of the mudflats are magnificent home of luxuriant mangroves.

Sundarbans features two ecoregions — “Sundarbans freshwater swamp forests” (IM0162) and “Sundarbans mangroves” (IM1406).[9]

The Sundarbans freshwater swamp forests are a tropical moist broadleaf forest ecoregion of Bangladesh. It represents the brackish swamp forests that lie behind the Sundarbans Mangroves, where the salinity is more pronounced. The freshwater ecoregion is an area where the water is only slightly brackish and becomes quite fresh during the rainy season, when the freshwater plumes from the Ganges and the Brahmaputra rivers push the intruding salt water out and bring a deposit of silt. It covers an area of 14,600 square kilometers (5,600 square miles) of the vast Ganges-Brahmaputra Delta, extending from the northern part of Khulna District and finishing at the mouth of the Bay of Bengal with scattered portions extending into India’s West Bengal state. The Sundarbans freshwater swamp forests lie between the upland Lower Gangetic plains moist deciduous forests and the brackish-water Sundarbans mangroves bordering the Bay of Bengal.[10]

A victim of large-scale clearing and settlement to support one of the densest human populations in Asia, this ecoregion is under a great threat of extinction. Hundreds of years of habitation and exploitation have exacted a heavy toll on this ecoregion’s habitat and biodiversity. There are two protected areas — Narendrapur (110 km2) and Ata Danga Baor (20 km2) that cover a mere 130 km2 of the ecoregion. Habitat loss in this ecoregion is so extensive, and the remaining habitat is so fragmented, that it is difficult to ascertain the composition of the original vegetation of this ecoregion. According to Champion and Seth (1968), the freshwater swamp forests are characterized by Heritiera minor, Xylocarpus molluccensis, Bruguiera conjugata, Sonneratia apetala, Avicennia officinalis, and Sonneratia caseolaris, with Pandanus tectorius, Hibiscus tiliaceus, and Nipa fruticans along the fringing banks.[10]

The Sundarbans Mangroves ecoregion on the coast forms the seaward fringe of the delta and is the world’s largest mangrove ecosystem, with 20,400 square kilometers (7,900 square miles) of area covered. The dominant mangrove species Heritiera fomes is locally known as sundri or sundari, after which the Sundarbans is thought to be named. Mangrove forests are not home to a great variety of plants. They have a thick canopy, and the undergrowth is mostly seedlings of the mangrove trees. Besides the sundari, other species that make up the forest include Avicennia spp., Xylocarpus mekongensis, Xylocarpus granatum, Sonneratia apetala, Bruguiera gymnorrhiza, Cereops decandra, Aegiceras corniculatum, Rhizophora mucronata, and Nypa fruticans palms.[11]

The physical development processes along the coast are influenced by a multitude of factors, comprising wave motions, micro and macro-tidal cycles and long shore currents typical to the coastal tract. The shore currents vary greatly along with the monsoon. These are also affected by cyclonic action. Erosion and accretion through these forces maintains varying levels, as yet not properly measured, of physiographic change whilst the mangrove vegetation itself provides a remarkable stability to the entire system. During each monsoon season almost all the Bengal Delta is submerged, much of it for half a year. The sediment of the lower delta plain is primarily advected inland by monsoonal coastal setup and cyclonic events. One of the greatest challenges people living on the Ganges Delta may face in coming years is the threat of rising sea levels caused mostly by subsidence in the region and partly by climate change.

In many of the Bangladesh’s mangrove wetlands, freshwater reaching the mangroves was considerably reduced from the 1970’s due to diversion of freshwater in the upstream area by neighboring India through the use of the Farakka Dam bordering Rajshahi, Bangladesh. Also, the Bengal Basin is slowly tilting towards the east due to neo-tectonic movement, forcing greater freshwater input to the Bangladesh Sundarbans. As a result, the salinity of the Bangladesh Sundarbans is much lower than that of the Indian side. A 1990 study noted that there “is no evidence that environmental degradation in the Himalayas or a ‘greenhouse’ induced rise in sea level have aggravated floods in Bangladesh”; however, a 2007 report by UNESCO, “Case Studies on Climate Change and World Heritage” has stated that an anthropogenic 45-cm rise in sea level (likely by the end of the 21st century, according to the Intergovernmental Panel on Climate Change), combined with other forms of anthropogenic stress on the Sundarbans, could lead to the destruction of 75% of the Sundarbans mangroves.[12] Already, Lohachara Island and New Moore Island/South Talpatti Island have disappeared under the sea, and Ghoramara Island is half submerged.[13]

The Sundarbans flora is characterized by the abundance of Heritiera fomes, Excoecaria agallocha, Ceriops decandra and Sonneratia apetala. A total 245 genera and 334 plant species were recorded by David Prain in 1903.[14] Since Prain’s report there have been considerable changes in the status of various mangrove species and taxonomic revision of the man-grove flora.[15] However, very little exploration of the botanical nature of the Sundarbans has been made to keep up with these changes. Whilst most of the mangroves in other parts of the world are characterized by members of the Rhizophoraceae, Avicenneaceae or Laganculariaceae, the mangroves of Bangladesh are dominated by the Sterculiaceae and Euphorbiaceae.[6]

The Bangladesh mangrove vegetation of the Sundarbans differs greatly from other non-deltaic coastal mangrove forests and upland forests associations. Unlike the former, the Rhizophoraceae are of minor importance. Differences in vegetation have been explained in terms of freshwater and low salinity influences in the Northeast and variations in drainage and siltation. The Sundarbans has been classified as a moist tropical forest demonstrating a whole mosaic of seres, comprising primary colonization on new accretions to more mature beach forests, often conspicuously dominated by Keora (Sonneratia apetala) and tidal forests. Historically three principal vegetation types have been recognized in broad correlation with varying degrees of water salinity, freshwater flushing and physiography and which are represented in the wildlife sanctuaries:

Sundari and Gewa occur prominently throughout the area with discontinuous distribution of Dhundul (Xylocarpus granatum) and Kankra. Among grasses and Palms, Poresia coaractata, Myriostachya wightiana, Imperata cylindrica, Phragmites karka, Nypa fruticans are well distributed. Keora is an indicator species for newly accreted mudbanks and is an important species for wildlife, especially spotted deer (Axis axis). Besides the forest, there are extensive areas of brackish and freshwater marshes, intertidal mudflats, sandflats, sand dunes with typical dune vegetation, open grassland on sandy soils and raised areas supporting a variety of terrestrial shrubs and trees.

Succession is generally defined as the successive occupation of a site by different plant communities.[16] In an accreting mudflats the outer community along the sequence represents the pioneer community which is gradually replaced by the next community representing the seral stages and finally by a climax community typical of the climatic zone.[17] Troup suggested that succession began in the newly accreted land created by fresh deposits of eroded soil.[18]

The pioneer vegetation on these newly accreted sites is Sonneratia, followed by Avicennia and Nypa. As the ground is elevated as a result of soil deposition, other trees make their appearance. The most prevalent, though one of the late species to appear, is Excoecaria. As the level of land rises through accretion and the land is only occasionally flooded by tides, Heritiera fomes begins to appear.

Mangrove Adaptations

Mangrove plants live in hostile environmental conditions such as high salinity, hypoxic (oxygen deficient) waterlogged soil strata, tidal pressures, strong winds and sea waves. To cope with such a hostile environment, mangroves exhibit highly evolved morphological and physiological adaptations to extreme conditions.

Do mangroves need salt?

The answer is no. Mangroves are facultative halophytes, i.e., the presence of salt in the environment is not necessary for the growth of mangroves and they can grow very well in freshwater as well. One particular advantage to growing in a salty environment is the lack of competition! Only a limited number of plants have invested evolutionary energy in adapting to intertidal conditions. In the optimum conditions of a tropical rainforest, diversity is great and competition fierce.

The Sundarbans provides a unique ecosystem and a rich wildlife habitat. According to the 2011 tiger census, the Sundarbans have about 270 tigers. Although previous rough estimates had suggested much higher figures close to 300, the 2011 census provided the first ever scientific estimate of tigers from the area[19][20] Tiger attacks are frequent in the Sundarbans. Between 100 and 250 people are killed per year.

There is much more wildlife here than just the endangered Royal Bengal Tiger (Panthera tigris tigris). Most importantly, mangroves are a transition from the marine to freshwater and terrestrial systems, and provide critical habitat for numerous species of small fish, crabs, fidler crabs, hermit crabs, shrimps and other crustaceans that adapt to feed and shelter, and reproduce among the tangled mass of roots, known as pneumatophores, which grow upward from the anaerobic mud to get the supply of oxygen. Fishing Cats, Macaques, wild boars, Common Grey Mongooses, Foxes, Jungle Cats, Flying Foxes, Pangolins, and spotted deer are also found in abundance in the Sundarbans.

A 1991 study has revealed that the Bangladeshi part of the Sundarbans supports diverse biological resources including at least 150 species of commercially important fishes, 270 species of birds, 42 species of mammals, 35 reptiles and 8 amphibian species. This represents a significant proportion of the species present in Bangladesh (i.e. about 30% of the reptiles, 37% the birds and 34% of the mammals) and includes a large number of species which are now extinct elsewhere in the country.[21] Two amphibians, 14 reptiles, 25 aves and five mammals are presently endangered.[22] The Sundarbans is an important wintering area for migrant water birds[23] and is an area suitable for watching and studying avifauna.[24]

The management of wildlife is presently restricted to, firstly, the protection of fauna from poaching, and, secondly, designation of some areas as wildlife sanctuaries where no extraction of forest produce is allowed and where the wildlife face few disturbances. Although the fauna of Bangladesh have diminished in recent times[6] and the Sundarbans has not been spared from this decline, the mangrove forest retains several good wildlife habitats and their associated fauna. Of these, the tiger and dolphin are target species for planning wildlife management and tourism development. There are high profile and vulnerable mammals living in two contrasting environments, and their statuses and management are strong indicators of the general condition and management of wildlife. Some of the species are protected by legislation, notably by the Bangladesh Wildlife (Preservation) Order, 1973 (P.O. 23 of 1973).[25]

The fertile soils of the delta have been subject to intensive human use for centuries, and the ecoregion has been mostly converted to intensive agriculture, with few enclaves of forest remaining. The remaining forests, together with the Sundarbans mangroves, are important habitats for the endangered Bengal Tiger (Panthera tigris). The forest also contains leopard (Panthera pardus fusca) and several other smaller predators such as the jungle cats (Felis chaus), fishing cats (Prionailurus viverrinus), and leopard cats (Prionailurus bengalensis).[10]

Several predators dwell in the labyrinth of channels, branches and roots that poke up into the air. This is the only mangrove ecoregion that harbors the Indo-Pacific region’s largest predator, the Bengal Tiger. Unlike in other habitats, tigers live here and swim among the mangrove islands, where they hunt scarce prey such as the Chital deer (axis axis), Indian Muntjacs(Muntiacus muntjak), Wild boars (Sus scrofa), and even Rhesus Macaque (Macaca mulatta). It is estimated that there are now 500[20] Bengal tigers and about 30,000 spotted deer in the area. The tigers regularly attack and kill humans who venture into the forest, human deaths ranging from 30-100 per year.[26]

Some of the reptiles are predators too, including two species of crocodiles, the Saltwater Crocodile (Crocodylus porosus) and Mugger crocodile (Crocodylus palustris), as well as the Gharial (Gavialis gangeticus) and the Water monitor lizards (Varanus salvator), all of which hunt on both land and water. Sharks and the Gangetic Dolphins (Platanista gangetica) roam the waterways.[27]

The forest is rich in bird life too with 170 species including the endemic Brown-winged Kingfishers (Pelargopsis amauroptera) and the globally threatened Lesser Adjutants (Leptoptilos javanicus) and Masked Finfoots (Heliopais personata) and birds of prey such as the ospreys (Pandion haliaetus), White-bellied Sea Eagles (Haliaeetus leucogaster) and Grey-headed Fish-eagles (Ichthyophaga ichthyaetus). The Sundarbans was designated a Ramsar site on May 21, 1992.[28] Some of the more popular birds found in this region are Open Billed Storks, White Ibis, Water Hens, Coots, Pheasant-tailed Jacanas, Pariah Kites, Brahminy Kites, Marsh Harriers, Swamp Partridges, Red Junglefowls, Spotted Doves, Common Mynahs, Jungle Crows, Jungle Babblers, Cotton Teals, Herring Gulls, Caspian Terns, Gray Herons, Brahminy Ducks, Spot-billed Pelicans, great Egrets, Night Herons, Common Snipes, Wood Sandpipers, Green Pigeons, Rose Ringed Parakeets, Paradise Flycatchers, Cormorants, Fishing Eagles, White-bellied Sea Eagles, Seagulls, Common Kingfishers, Peregrine falcons, Woodpeckers, Whimprels, Black-tailed Godwits, Little Stints, Eastern Knots, Curlews, Golden Plovers, Pintails, White Eyed Pochards and Whistling Teals.

Some of the fish and amphibians found in the Sunderbans are Sawfish, Butter Fish, Electric rays, Silver carp, Barb (fish), River Eels, Star Fish, Common Carp, King Crabs, Prawn, Shrimps, Gangetic Dolphins, Skipping Frogs, Common Toads and Tree Frogs. One particularly interesting fish is the mudskipper, a gobioid that climbs out of the water into mudflats and even climbs trees.

The Sundarbans National Park houses an excellent number of reptiles as well. Some of the common ones are Olive Ridley turtles, sea snakes, Dog Faced Water Snakes, Green Turtles, Estuarine Crocodiles, Chameleons, King Cobras, Salvator Lizards, Hard Shelled Batgun Terrapins, Russels Vipers, Mouse Ghekos, Monitor Lizards, Curviers, Hawks Bill Turtles, Pythons, Common Kraits, Chequered Killbacks and rat Snakes. The river terrapin (Batagur baska), Indian flap-shelled turtles (Lissemys punctata), peacock soft-shelled turtles (Trionyx hurum), yellow monitors (Varanus flavescens), water monitors (Varanus salvator), and Indian pythons (Python molurus) are some of the resident species.

The endangered species that live within the Sundarbans are Royal Bengal Tigers, Estuarine Crocodile, River Terrapins (Batagur baska), Olive Ridley Turtles, Gangetic dolphin, Ground Turtles, Hawks Bill Turtles and King Crabs (Horse shoe). Some species such as hog deer (Axis porcinus), water buffalos (Bubalus bubalis), swamp deer (Cervus duvauceli), Javan rhinoceros (Rhinoceros sondaicus), single horned rhinoceros (Rhinoceros unicornis) and the mugger crocodiles or marsh crocodiles (Crocodylus palustris) started to become extinct in the Sundarbans towards the middle of the 20th century, due to extensive poaching and man hunting by the British.[22] There are several other threatened mammal species, such as the capped langurs (Semnopithecus pileatus), smooth-coated otters (Lutrogale perspicillata), Oriental small-clawed otters (Aonyx cinerea), and great Bengal Civets (Viverra zibetha).

The Sundarbans has a population of over 4 million[29] but much of it is mostly free of permanent human habitation.

The Sundarbans plays an important role in the economy of the southwestern region of Bangladesh as well as in the national economy. It is the single largest source of forest produce in the country. The forest provides raw materials for wood based industries. In addition to traditional forest produce like timber, fuelwood, pulpwood etc., large scale harvest of non wood forest products such as thatching materials, honey, bees-wax, fish, crustacean and mollusk resources of the forest takes place regularly. The vegetated tidal lands of the Sundarbans also function as an essential habitat, produces nutrients and purifies water. The forest also traps nutrient and sediment, acts as a storm barrier, shore stabilizer and energy storage unit. Last but not the least, the Sunderbans provides a wonderful aesthetic attraction for local and foreign tourists.

The forest also has immense protective and productive functions. Constituting 51% of the total reserved forest estate of Bangladesh, it contributes about 41% of total forest revenue and accounts for about 45% of all timber and fuel wood output of the country (FAO 1995). A number of industries (e.g. newsprint mill, match factory, hardboard, boat building, furniture making) are based on the raw materials obtained from the Sundarbans ecosystem. Various non-timber forest products and plantations help generate considerable employment and income generation opportunities for at least half a million poor coastal population. It also provides natural protection to life and properties of the coastal population in the cyclone prone Bangladesh.

Despite human habitations and a century of economic exploitation of the forest well into the late forty’s, the Sundarbans retained a forest closure of about 70% according to the Overseas Development Administration (ODA) of the United Kingdom in 1979. At the behest of Ziaur Rahman, the President of Bangladesh, the government of the UK was then able to conduct an indepth research thanks to possession of important past records.

Forest inventories reveal a decline in standing volume of the two main commercial mangrove species — sundari (Heritiera spp.) and gewa (Excoecaria agallocha) — by 40% and 45% respectively between 1959 and 1983 (Forestal 1960 and ODA 1985). Despite a total ban on all killing or capture of wildlife other than fish and some invertebrates, it appears that there is a consistent pattern of depleted biodiversity or loss of species (notably at least six mammals and one important reptile) in this century, and that the “ecological quality of the original mangrove forest is declining” (IUCN 1994).

A Panaroma atop an observation post at Hiron Point Wild Life Sanctuary, Khulna Range, Bangladesh

The Sundarbans area is one of the most densely populated in the world, and the population is increasing. As a result, half of this ecoregion’s mangrove forests have been cut down to supply fuelwood and other natural resources. Despite the intense and large-scale exploitation, this still is one of the largest contiguous areas of mangroves in the world. Another threat comes from deforestation and water diversion from the rivers inland, which causes far more silt to be brought to the estuary, clogging up the waterways.

The Bangladesh part of the forest lies under two forest divisions, and four administrative ranges viz Chandpai (Khulna District), Sarankhola (Khulna), and Burigoalini (Satkhira District) and has sixteen forest stations. It is further divided into fifty-five compartments and nine blocks.[1] There are three wildlife sanctuaries established in 1977 under the Bangladesh Wildlife (Preservation) Order, 1973 (P.O. 23 of 1973).

Protected areas cover 15% of the Sundarbans mangroves including Sundarbans National Park and Sajnakhali Wildlife Sanctuary, Sundarbans East, Char Kukri-Mukri, Sundarbans South and Sundarbans West Wildlife Sanctuaries in Bangladesh.[11]

A new Khulna Forest Circle was created in Bangladesh back in 1993 to preserve the forest, and Chief Conservators of Forests have been posted since. The direct administrative head of the Division is the Divisional Forest Officer, based at Khulna, who has a number of professional, subprofessional and support staff and logistic supports for the implementation of necessary management and administrative activities. The basic unit of management is the compartment. There are 55 compartments in four Forest Ranges and these are clearly demarcated mainly by natural features such as rivers, canals and creeks.

The Sunderbans is celebrated through numerous Bengali folk songs and dances, often centered around the folk heroes, gods and goddesses specific to the Sunderbans (like Bonbibi and Dakshin Rai) and to the Lower Gangetic Delta (like Manasa and Chand Sadagar). The Bengali folk epic Manasamangal mentions Netidhopani and has some passages set in the Sunderbans during the heroine Behula’s quest to bring her husband Lakhindar back to life.

The area provides the setting for several novels by Emilio Salgari, (e.g. The Mystery of the Black Jungle). Sundarbaney Arjan Sardar, a novel by Shibshankar Mitra, and Padma Nadir Majhi, a novel by Manik Bandopadhyay, are based on the rigors of lives of villagers and fishermen living in the Sunderbans region, and are woven into the Bengali psyche to a great extent. Padma Nadir Majhi was also made into a movie by Goutam Ghose. Part of the plot of Salman Rushdie’s Booker Prize winning novel, Midnight’s Children is also set in the Sundarbans. This forest is adopted as the setting of Kunal Basu’s short story “The Japanese Wife” and the subsequent film adaptation. Most of the plot of prize-winning anthropologist Amitav Ghosh’s 2004 novel, The Hungry Tide, is set in the Sundarbans. The book mentions two accounts of the Banbibi story of “Dukhey’s Redemption.”[30]

The Sunderbans has been the subject of numerous non-fiction books, including The Man-Eating Tigers of Sundarbans by Sy Montegomery for a young audience, which was shortlisted for the Dorothy Canfield Fisher Children’s Book Award. In Up The Country, Emily Eden discusses her travels through the Sunderbans.[31] Numerous documentary movies have been made about the Sunderbans, including the 2003 IMAX production Shining Bright about the Bengal Tiger. The acclaimed BBC TV series Ganges documents the lives of villagers, especially honey collectors, in the Sundarbans.

Content from:  wikipedia.org

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