Presented in the International Geosphere Biosphere Programme (IGBP) SIE LDCs Workshop at Maputo, Mozambique Held on September 20-22, 2010
Bangladesh has a difficult coastline with many rivers and distributaries and complex ecology which is affected by natural hazards like cyclones, coastal flooding, tidal surges, salinity and the like phenomenon. The coastline is of 734 km involving coastal and island communities of about 50 million people, nearly about one-third of the total population of Bangladesh. Vulnerabilities in the coastal zone of Bangladesh are increasing with accentuations of natural hazards and sea level rise caused by various factors. Research findings, grey literature and indigenous knowledge are to be surveyed to develop policies for sustainable coastal zone management.
Coastal zones are the interfaces of land and ocean balancing geosphere, atmosphere and biosphere; major biological activity centres favorable for easy living and about 3 billion people are living in the coastal zones (Enemark, 2007; Connolly, 2001 and World Bank, 1993. The intermittent key players of hydrological cycles; rivers and distributaries from the lands and the ocean currents and waves accumulate huge organic and geochemical substances; thus make highly productive zones with important sources of food and raw materials, energy, minerals, recreation, transport, and trade. Coasts also host an impressive array of valuable habitats with an equally extraordinary collection of species (Bird and Muluk et al. 1979). Excellent landscapes are found on sea shores where many spas and recreation zones are located on the places; wide and clean sea beach are located near green coastal forests shrubbery including mangroves, palms and nuts are of particular value. They are the best natural defense for keeping the shoreline intact from abrasions (Astanin and Blagosklonov, 1983).
However, worldwide coastal zones face serious problems of habitat destruction, pollution, erosion and resource depletion due to human economic activities and climate change effects (FAO, 1998). Coastal resource depletion leads to frequent conflict between users and also suffer from serious socio-economic and cultural problems, such as weakening of the social fabric, marginalization, unemployment and destruction of property by erosion. Moreover, unregulated removal of sand, gravel and pebble deposits from beaches and underwater coastal slopes has been creating threat to the coasts (Banica et al. 2003; Bird 1979 and Bird and Ongkosongo, 1980).
With the increasing rate of global temperature, oceanic thermal expansion would raise sea level by 4-8 cm. It is estimated that by the 2080s, sea-level rise could cause the loss of up to 22% of the world’s coastal wetlands. When combined with other losses due to direct human action, up to 70% of the world’s coastal wetlands could be lost by the 2080s (Sarwar, 2005 and Nicholas et al., 1999).
A combination of human activities like over-fishing, pollution of estuaries and the coastal ocean, and the destruction of habitat, especially wetlands and sea-grasses etc., currently exerts a far more powerful effect on world marine fisheries than is expected from climate change. Experts are suggesting that the greenhouse effect will enhance the seasonal warming of continents leading to a decrease in the pressure over land, an increase in the land–sea pressure difference, and an increase of alongshore winds. The strength of both oceanic and coastal upwelling mechanisms could change under conditions of global warming, with profound impacts upon fish species and their production as well as on the climate of the immediate coastal zone. The principal effects of climate change on marine mammals and seabirds are expected from aerial shifts in centers of food production and changes in underlying primary productivity due to changes in upwelling, loss of ice-edge effects, and ocean temperatures; changes in critical habitats such as sea ice and nesting and rearing beaches due to sea-level rise; and increases in diseases and production of oceanic bio-toxins due to warming temperatures and shifts in coastal currents.
Several large African cities are at risk from rising sea levels and intense storms. In sub-Saharan Africa, storm surge zones are concentrated in Madagascar, Mauritania, Mozambique and Nigeria. These countries alone account for about 53% of the total increase in the region’s surge zones resulting from sea level rise and intensified storms.
At least 2.5 million people live in Mozambique’s coastal areas, surviving on rain-fed farming and fishing. But migration to coastal towns is placing more people, infrastructure and services at risk and more severe cyclones will pose the biggest threat to the Mozambique coast beyond 2030, the accelerating sea level rise will present the greatest danger, especially when combined with high tides and storm surges.
Researchers project a 3-5% increase in wind speed per degree Celsius increase of tropical sea surface temperatures and ocean warming plays a major role in intensified cyclone activity and heightened storm surges. Coastal agriculture, in terms of extent of croplands, will be affected 100% in Nigeria, 66.67% in Ghana, and 50% in Togo and Equatorial Guine(IRIN-2009). Other impacts of climate change may further enhance or mitigate coastal flooding. Flooding from rainstorms may become worse if higher temperatures lead to increasing rainfall intensity during severe storms. An increase in the intensity of tropical storms would increase flood and wind damages.
Coastal zone scenario of Bangladesh
Majority of the LDCs of Asia and Africa including Bangladesh are in the coastal zones. However, Bangladesh has a difficult coastline with many rivers and distributaries and complex ecology which is affected by natural hazards like cyclone, coastal flooding, tidal surges, salinity and other phenomenon. The coastline is of 734 km involving coastal and island communities of about 50 million people, nearly one-third of the total population of Bangladesh (Miyan, 2009 and Rahman, 2010).
The Ganges, Brahmaputra and Meghna estuaries in the south and the Karnaphuli, Halda and Sangu rivers and Arakan ranges shoreline in the southeast are giving a distinct feather of the whole coastal zones. It has the opportunities like, fertile land, fishing, mangrove forests, marine and terrestrial biodiversity, scenic beauty, ports, industries, tourism, marine resources, and minerals: Quartzes and Zircon, Uranium; easy transportation and sailing facilities, and meeting point of fresh and saline water flora and fauna and salt fields, etc.
Fig. 1 Himalaya and Deltaic Bengal
The coastal zones have excellent natural defense systems with Arakan hill ranges along Chittagong and Cox’s Bazar shoreline, strong windbreaks with hill forests in the eastern coast of the Bay of Bengal and dense Sundarbans mangrove forests with triple tier protection mechanisms. Sea currents, web and tides and upstream fresh water flows play a very important role for enriching the coastal zones of Bangladesh.
Fig. 2 Satellite Image of Bangladesh
Fig. 4 Coastal Zone of Bangladesh
However, some problems often create disasters and make the lives hard and the whole coastal ecosystem is being disturbed. Among them, tropical cyclones and tornados, tidal surges and floods, erosion, heavy siltation and pollution, especially from the mega-cities and ports, shrimp hatchery and shrimp farms. Deforestation, over fishing and salt fields, overexploitation, and hill cutting for unplanned construction, ships breaking industries and tourism have accelerated ecosystem damages.
Fig. 5 Coastal Erosion and Siltation
Fig. 6 Siltation & Narrowing of River Flows
Figs. 7 Salinity Intrusion in Two Decades
Cyclones Affected Regions Wind Speed km/hr Deaths Damages US $ in million
Bhola Cyclone-1970 Bangladesh, India 205 500,000 86.4
Bangladesh Cylone-1991 Bangladesh 260 138,000 1,500
Sidr-2007 Bangladesh 260 4,036 1,700
Nargis-2008 Myanmar Bangladesh India, Srilanka 215 138,366
(126 in Bangladesh) 10,000
India 120 325
(26 in Bangladesh) 552.6
Table-1 Tropical Cyclones Affected Coastal Zones
Figs. 8 Dying of trees due to water-logging and salinity in Chittagong
Fig. 9 Cox’s Bazar, Longest Sea Beach
Fig. 10 Eroded Sea Beach Cox’s Bazar under a great threat
Fig. 11 Chemical Effluent from Shrimp Hatchery
The Sundarbans is the world’s largest Mangrove forests the National Park of Bangladesh, declared as Tiger Reserve declared in 1973, UNESCO World Heritage Site (UNESCO-1987) and a Biosphere Reserve in 1989 is located in the Ganges, and Brahmaputra and Meghna in Bangladesh and West Bengal (India) coast with an area 16,902 km2.
Fig. 12 Sundarbans Largest Mangrove Forests
This region is densely covered by mangrove forests, and is one of the largest reserves for the Bengal tiger and fishing cat, spotted deer, rhesus monkey and wild pigs. It is also home to a variety of bird, reptile and invertebrate species, including the salt-water crocodile.
Figs. 13 Man-eating Royal Bengal Tiger, Crocodile and Spotted Deer of Sundarbans
The mangrove vegetation of Sundarbans consists of 64 plant species (UNEP-WCMC-2008) and they have the capacity to withstand estuarine conditions and saline inundation on account of tidal effects. Sundari (Heritiera fomes), Gewa (Excoecaria agallocha), Kankra (Bruguiera gymnorrhiza), Passur (Xylocarpus mekongensis, Rhizophora spp., Sundari (Heritiera fomes) and Goran (Ceriops decandra).
Some of the more popular birds found in this region are openbill storks, black-headed ibis, Water Hens, Coots, Pheasant-tailed Jacanas, Pariah Kites, Brahminy Kite, Marsh Harriers, Swamp Partridges, Red Jungle-fowls, Spotted Doves, Common Mynahs, Jungle Crows, Jungle Babblers, Cotton Teals, Herring Gulls, Caspian Terns, Gray Herons, Brahminy ducks, Spot-billed Pelicans, Large 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, Whimbrels, Black-tailed Godwits, Little Stints, Eastern Knots, Curlews, Golden Plovers, Northern Pintails, White Eyed Pochards and Whistling Teals etc.
Some of the fish and amphibians found in the park are Sawfish, Butter Fish, Electric rays, Silver carp, Star Fish, Common Carp, King Crabs, Prawn, Shrimps, Gangetic Dolphins, Skipping Frogs, Common Toads and Tree Frogs.
Figs. 14 Natural beauty of Sundarbans and Sundarbans after Sidr 2007
The Sundarbans National Park houses an excellent number of reptiles as well, including estuarine crocodiles, chameleons, water monitors, Hard Shelled Batgun Terrapins, Mouse Ghekos, monitor lizards, and Cuvier’s Dwarf Caiman; turtles, including Olive Ridley, hawksbill, and green turtles; and snakes including pythons, King Cobras, rat snakes, Russell’s vipers, Dog Faced Water Snakes, Chequered Killbacks, and Common Kraits.
Some endangered species of Sundarbans are Royal Bengal Tiger, Estuarian Crocodile, River Terrapin (Batagur baska), Olive Ridley Turtle, Gangetic dolphin, Ground Turtle, Hawks Bill Turtle and King Crabs (Horse shoe) etc.
Though there is tough protection in the park there are a few loopholes. The geographical topography with hostile terrain crisscrossed by several rivers and their distributaries, long international border with Bangladesh, fishing trawlers and launches helps in poaching, cutting of wood and also affecting the mangrove forests. Lack of staffs, infrastructure and lack of funds also added up the factors.
Vulnerabilities in the coastal zone are increasing with accentuations of natural hazards caused by environmental degradation, climate change and human activities as well as exploitation of mangrove. It has already affected Bangladesh by land erosion, salinity intrusion and loss in biodiversity. Its potential threats are coming even strongly in the future. Due to climate change effects, the incidences of tropical storms and tidal surges have been increased in the coastal belts of Bangladesh, India, Myanmar and Sri Lanka. The cyclones viz. Sidr, Aila and Nargis are the typical examples which have caused significant damages of lives and properties of the coastal zones.
Fig. 15 Vulnerable Sites of Coastal Zone
Fig. 16 Effect of Tropical Cyclone Aila Nov 25, 2009
Fig. 17 Effect of Sidr Nov 25, 2007
Further sea level rise will cause river bank erosion, salinity intrusion, flood, damage to infrastructures, crop failure, fisheries destruction, order prescription drugs online loss of biodiversity, etc. along this coast. One-meter sea level rise will affect the country’s vast coastal area and flood plain zone. It will affect MDGs, causing environmental refugees. Most vulnerable sectors to one meter rise are coastal ecosystem of Bangladesh. Continuing development technology and urbanization, especially in the coastal zones, huge toxic materials, from the industries like textile and dying, hide-skin and leather, medicine, pesticide and fertilizer industries etc., are being poured into the drains, canals and rivers and ultimately to the Bay resulting chemical changes in water quality (Rahman, 2009). Moreover, hypoxia from agriculture and animal raring, processing of organic matter and sewage changes in land use leading to destruction of mangroves and massive loss of coastal lives and property, as well as translocation of populations.
Figs. 18 Hazards of Ship breaking industries
Shrimp hatchery and shrimp hatchery pose a great threat to coast line. Cox’s Bazar is the world’s longest sea beach is under threat of erosion due to disposal of effluents from the shrimp hatcheries. Moreover, expansion of sea beach hotels, motels and recreation zone by cutting shoreline hills has destroyed a great part of the beach which needs immediate attention from further destruction. Due to availability of cheap laborers, ship breaking industry is growing very fast in the coastal zone mainly concentrated in Sitakund, Baroawlia, Bhatiari and Kumira, just north of Chittagong city on the Bay of Bengal. Ship-breaking activities present both challenges and opportunities for our coastal zone management. Meeting the increasing demand for raw materials such as steel needs to be balanced with the negative impact this activity is having on our coastal environment and the conditions of the workers. In Bangladesh, ships containing lead, cadmium, organo-tins, arsenic, zinc and chromium, oils, organophosphates, asbestos, materials are being cut up and handles manually, on open beaches, with no consideration given to safe and environmentally friendly waste management practices which can result in lung cancer, cancer of the skin, intestine, kidney, liver or bladder and damage blood vessels.
Ships are not properly cleaned before beaching. Generally, an eyewash test is carried out to certify that a ship is free from dangerous chemical and fumes.
Ship breaking activities is a threat to both the terrestrial and marine environment as well as to public health. It is like a mini version of a city that discharges every kind of pollutants a metropolis can generate like liquid, metal, gaseous and solid pollutants. Oil films on water reduce the exchange of oxygen and carbon dioxide across the air-sea interface which is harmful to aquatic life. It also causes damage to the bird population by coating their feathers with oil which causes buoyancy and insulation losses. Sometimes spilling may cause wide spread mortality amongst the population of fish, mammals, worms, crabs, mollusks and other water organisms. Furthermore, oil spilling may cause serious damage by reduction of light intensity, inhibiting the exchange of oxygen and carbon dioxide across the air-sea water interface, and by acute toxicity. As a result the growth and abundance of marine organisms especially plankton and fishes may seriously be affected. Indiscriminate expansion of ship breaking activities poses a real threat to the coastal inter-tidal zone and its habitat (YPSA-2010)
A huge wastes and toxic materials are being dumped everyday in the Bay. Many people die during exposition of gas cylinders and lack of proper safety measures. There should be a specific rules and regulation for such activities in the coastal zones.
With the growing concern of coastal ecosystem damages Bangladesh has taken some protective measures to protect lives and resources with massive coastal afforestation, making shelter houses and freshwater reservoirs. National policy has been made under a specific guideline “Standing Orders on Disasters (SOD). Researches are in progress for development of salinity tolerant crops and in the mean time, Bangladesh Rice Research Institute (BARI) has developed high yielding salinity tolerant rice varieties BRRI dhan-47 for irrigated and BRRI dhan-40 and 41 for rain fed conditions.
Habitat of wildlife is well-maintained through eco-conservation, eco-development, training, education and research. 10 Forest Protection Committees and 14 Eco-development Committees have been formed in the fringe of Sundarbans Tiger Reserve helps in this regard. Seminars, workshops, awareness camps, etc. are organized frequently in the vicinity of park to educate the people on eco-conservation, eco-development and such other issues. Mangrove and other plants are planted in the fringe area to meet the local need of fuel wood for about 1000 villages and to conserve the buffer area. Conservation of soil is done to maintain the ecological balance. Several sweet water ponds have been dug up inside the park to provide drinking water to the wild animals.
Fig. 19 Patrolling boat in Sundarbans
Fig. 20 Manmade Freshwater Reservoir in the Coastal Zone
Controlling man-eating tigers is another major activity. The number of casualties has been reduced from 40 to 10 per year. The reduction in number of casualties is a result of strict control over the movement of the people inside the tiger reserve, alternative income generation and awareness building among people. The Mangrove Interpretation Centre is established at Sajnekhali to make the local people and tourists aware about importance of conservation of nature in general and specially the mangrove eco-systems.
Adaptation and Sustainability
Adaptation and mitigation are two options for Bangladesh of which the first one is country specific, or even local specific, but mitigation demands collective efforts of global communities. Development of adaptation policies for different sectors will help Bangladesh to face the crucial hazards of sea level rise.
Figs. 21 Cyclone Shelter cum Schools in Coastal Zone
Case studies involving different aspects of coastal zone management in Bangladesh are likely to point out to policy implication which may be also relevant to countries like Myanmar, Cambodia and Yemen. From the Table 1, Case Studies reveal that Bangladesh is greatly successful in reducing human death toll but structural, livestock and resource damages have been increased which needs more research on coastal zone management. Research findings, grey literature and indigenous knowledge are also needed to be incorporated into a regional, zonal, national and international policy for sustainable coastal zone management.
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10. Newton, A., Global Change and Coastal Zone: Current LOICZ Science Activities: Land-Ocean Interections in the Coastal Zone (LCOICZ)
11. Nicholls, R.J., Hoozemans, F.M.J., Marchand, M., 1999. Increasing flood risk and wetland losses due to global sea-level rise: regional and global analyses, Global Environmental Change 9, pp.S69-S87
12. Rahman, M.A. 2009: Recycled water can mitigate drinking water crisis, The Independent, December 12, 2009.
13. Rahman, M.A. 2010: Wetland Preservation in Dhaka City Area http://feppcar.org/103/wetland-preservation-in-dhaka-city-area/
14. Rahman, M.A., 2010 Sustainable Landscape Management of Bangladesh, Under Publication
15. Sarwar, GM, 2005: Impact of Sea level Rise in the Coastal Zones of Bangladesh http://www.lumes.lu.se/database/alumni/04.05/theses/golam_sarwar.pdf.
17. YPSA-2010, Ship breaking in Bangladesh: Environmental Pollution http://www.shipbreakingbd.info/Environment.html
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