Wetland Resources in Bangladesh Saroar M. Mustafa Concept, Types and Status of Wetlands in Bangladesh: The Ramsar Convention (1971) has defined wetlands as – areas of marsh, fen, peat-land, or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres. The Ramsar definition of wetlands lumps together a wide range of contrasting habitats like fluvial, coastal and marine.
Nevertheless, the Ramsar definition has been adopted and being used in Bangladesh. Wetlands of Bangladesh are classified on the basis of their hydrological and ecological functions and land types. Broadly wetland in Bangladesh is divided into estuarine and freshwater systems, which again further subdivided by soil type and plant life. Thus wetlands include areas of marsh, fen, bog, flood plain, and shallow coastal areas.
Wetland area is characterized by sluggish or standing water that can create an open water habitat for wildlife.
As I mentioned earlier wetlands in Bangladesh are represented by both inland freshwater and estuarine/tidal salt-water wetlands. Flood plains, beels (low-lying depressions in the flood plain), haors and baors (oxbow lakes) represent the inland freshwater wetlands (Khan et al. 1994). The haors are bowl-shaped natural depressions between the natural levees of the river subject to monsoonal flooding every year.
While the haor itself is a seasonal water body formed during the monsoon, the beels are low-lying depressions of the haor system retaining water even during the dry months of the season.
Thus, the haor system is a complex of both lacustrine and palustrine wetlands depending on the hydraulic behavior in different seasons. The ecology of the haor system is principally driven by seasonal hydraulics. During the monsoon, the entire haor system becomes a single body of open water linked to the river system.
When floodwater recedes, the beels become isolated and remain as standing water bodies till the next rainy season. They differ from a true lake system in that the main source of waters in tropical lakes is rainwater, while a haor system depends on both precipitation and floodwater as sources of water. Estuarine/tidal salt-water wetlands constitute about 25 per cent of the land area and are represented by mangroves, salt marsh, lagoons, deltaic islands, sand dunes and beaches, barrier islands, sea grass and coral habitats.
In the following table major types of wetlands of Bangladesh are presented. 1. Saltwater wetlandsa) Marine permanent shallow waters at low tide, eg bay coral reefs, eg St Martin’s reef b) Estuarine intertidal mud, sand or salt flats with limited vegetation, eg newly-accreted land intertidal marshes intertidal forest wetlands including mangroves, eg Sundarbans c) Lagoonal brackish to saline lagoons with narrow connection with sea 2.
Freshwater wetlandsa) Riverine wetlands permanent rivers and streams including some char land, temporary seasonal rivers and streams b) Lacustrine wetlands There are thousands of lakes of varying sizes in Bangladesh, the greatest concentrations being in the main delta region covering the districts of Rajshahi, Pabna, Khulna, Jessore, Faridpur, Comilla and Noakhali. c) Palustrine wetlands permanent freshwater marshes and swamps with emergent vegetation, permanent peat-forming freshwater swamps, freshwater swamp forest, eg hijal forests of lowland 3.
Man-made wetlands aquaculture ponds (brackish and freshwater) irrigated land and irrigation channels salt pans hydro-dam, eg Kaptai Lake However, the areal extent of wetlands in the above classification is not available. A different classification is show to give idea about the wetland in Bangladesh which is rather indicative than exact as primarily because size of each wetland varies depending on season; Monsoon, for example when area under wetland increase by contrast during wet season it shrink. Types of wetlands and their areas (in sq km) Open waters Rivers7,497
Estuaries and mangrove swamps 6,102 Beels and haors 1,142 Inundable floodplains54,866 Kaptai Lake688 Closed water/Ponds 1,469 Baors (Oxbow Lakes) 55 Brackish-water farms1,080 Total72,899 Source Khan 1994 Significance of Wetlands in Context of Bangladesh: Wetlands are critically important in Bangladesh for human settlements, biodiversity, fisheries, agricultural diversity, navigation & communication, and ecotourism. These are discussed in some details in the following sections. In a land scare country like Bangladesh where average population density is almost 1000 person per sq. m people in the marginalized category build their habitat/settlement in the wetland in the event of acute shortage of buildable high land. Flood plain areas are the treasure-house for rice- the staple food of Bangladeshi people. More than 100 varieties, some of which are even deep water tolerant, local rice are cultivated in these floodplains. Thus floodplain is the power house of rural economy in Bangladesh. Similarly in the wetlands of Bangladesh more than 250 species of freshwater fishes are available.
Freshwater capture fishery is an important source of employment in the fishery sector and the key supply source of animal protein especially for the rural people. About 200 million people still directly or indirectly depend on freshwater fishing for their livelihood (Tsai, and Ali, 1997). A part from that, wetlands are valuable sources of food (vegetable), fuel, fodder and traditional medicine in rural Bangladesh. For a vast tract of areas especially in the north-east, south and south-central part of Bangladesh both perennial and seasonal floodplains are they key means of transport and communication for the rural people.
In the context of biodiversity (which includes: plant diversity, faunal diversity and habitat diversity) wetlands in Bangladesh perform significant role. These are important habitats for a large variety of flora and fauna of local, national and regional significance. In the freshwater wetlands the floral composition includes trees, shrubs and aquatic vegetation. More than 5,000 species of flowering plants exist in these wetland areas (Khan, 1998).
Here wetlands support 660 species of birds which represents about 50% of the total number of bird species recorded from the entire Indian sub-continent, and over 7% of the known bird species in the world (Harvey 1992). On the other hand, rich aquatic biodiversity also includes 260 species of freshwater fish belonging to 55 families (placing Bangladesh third in the world in terms of fish species per land area) (Tsai and Ali, (Eds). 1997). At any rate, the known levels of endemism in the Ganges/Brahmaputra basin are very high: 25% of the aquatic species found in this basin are found nowhere else in the world.
Because of its geographical position at the receiving end of the three major rivers, and given the dispersal behavior of aquatic biodiversity, the wetlands of Bangladesh become crucial for conserving the globally important biodiversity of the entire basin (Hussain, 1997). Likewise, the estuarine/ marine resources of the Bay of Bengal are part of the world’s largest malacological province. These resources include clams, oysters, scallops, snails, slugs, chiton, squids, octopuses and some others.
The ichthyo-fauna of the Bay of Bengal includes about 475 recorded species of fish, 53 of which are cartilaginous and 422 species are bony fish (IUCN, 1989). Chowdhury and Sanaullah (1991) described 19 species of shrimps and prawns found in the marine waters of Bangladesh. At least seven species of edible oyster can be found in the coastal waters of Bangladesh. Apart from those wetlands perform significant ecological and environmental services and functions which could not be replaced by artificial means or adopting artificial method would entail significant cost. Among other the role of purification of water in the marsh is an important one.
From the foregoing discussion it is evident that have a wide range of ecological, socio-cultural, economic and commercial importance and values in Bangladesh. Causes and Consequence of Wetland Degradation: Various development interventions/activities undertaken without much consideration of wetland ecosystems in the post independent period of Bangladesh have caused irreversible damage to the wetlands. For example, massive physical infrastructures in the form of rural road and flood embankment have been developed in the wetlands including floodplains and haor areas.
Many of these infrastructures disregarded local topographic condition and natural water flow direction, which has often resulted in poor drainage or water logging and impacted on the local surface water regime. The critical point of such development activities in the wetlands led the transformation very rapidly at a massive scale. In the Ganges-Brahmaputra floodplain area, about 2. 1 million ha of wetland have been lost to Flood Control, Drainage and Irrigation development projects (FCDI).
Introduction of HYV of rice which requires high inputs like mechanical tillage, chemical fertilizer, insecticide, herbicide, fungicide in fact caused irrecoverable damage of wetland habitat for freshwater fish and birds at the expense of higher food yield. In this indiscriminate use of agro-chemical and over exploitation of fish stock, especially brood fish by fisher community for their livelihood put the freshwater fish stock at the verge of extinction. A part from the above other human interference in the wetlands has been damaging the fragile ecosystem and to long term sustainability of the wetlands.
For instance, in the southwest brackish water coastal plains of Bangladesh farmers used to have a paddy crop only during monsoon season when surface saline layer is depleted due to rainfall and for rest of the months the field is left for grazing. This cultural practice was established for centuries. However, in the last two decades this has been abandoned for more profitable shrimp farming practice. As a result, local ecosystems are threatened because of changed water exchange system, rapid siltation of the channels and continuous inundation of land with saline water.
In the haor areas, large-scale settlement was initiated over the last couple of decades from surrounding densely populated regions and since then the resources of the haor basins are being exploited at an increasing rate causing adverse effects. Continuous large-scale exploitation of aquatic vegetation and fruits has caused serious degradation of the quantity and quality of the habitat required for fish and migratory birds of the haor areas. Similarly, embankment constructed for FCDI projects reduce floodplains and obstruct fish movement and migration from rivers as well as beels to the remaining floodplains for feeding and breeding.
As a result, many fishermen have lost their livelihood. However, there have been some positive effects of wetland transformation as well. The major impact has been on cropping patterns and intensity. Dependence on local boro has been shifted towards HYV boro. In the FCDI project areas, culture fisheries have replaced the deficit of capture fisheries. The positive impact of development projects in the wetlands relates to improved road transport and communication network. This has led to an enhanced marketing infrastructure and relatively easy access to social and other services.
Conversely, the navigation system has been either closed or substantially reduced. As a whole, degradation of wetlands has caused several problems including extinction and reduction of wildlife, extinction of many indigenous wild and domesticated rice varieties, loss of many indigenous aquatic plants, herbs, shrubs and weeds, loss of natural soil nutrients, loss of natural water reservoirs and of their resultant benefits, increase in the occurrence of flooding and degeneration of wetland based ecosystems, occupations, socio-economic institutions and cultures.
Plan and Activities to Conserve Wetland: Overt the yeast Bangladesh Ministry of Water resources development, Land, Forest and Environment, and Fisheries and livestock in cooperation with various multilateral agencies ( like Worldbank, ADB), bilateral agencies (like USAID, DANIDA, JICA), intergovernmental agencies, and NGO (both international and national) initiated various institutional reform, plan and program to conserve and manage water resources in an efficient ways.
Even though in most cases the focus of those programs were not on conservation of wetland however recently recognizing both the importance of conserving biological resources and the need for new approaches to floodplain, wetlands, and forest conservation and management, USAID/Bangladesh, in conjunction with the Ministry of Fisheries and Livestock (MoFL), is implementing the Management of Aquatic Ecosystems through Community Husbandry (MACH) project to help promote the conservation and sustainable management of critical floodplain and wetland habitats (USAID, 2002).
Likewise, DFID in cooperation with the Ministry of Land, Ministry of Fisheries and Livestock (MoFL), is implementing Community Based Fisheries Management (CBFM). Apart from these IUCN [at present World Conservation Union] is implementing Wetland and Coastal Biodiversity project which has exclusive focus on haor, and estuarine/marine wetland ecosystem conservation. A part from the above there are relevant laws and acts and ordinance focusing on the conservation of environmentally critical areas, especially on wetlands.
For example, Environmental Protection Act 1995, Environmental Conservation Rule 1997, Environmental Conservation Rule 2002 (amended) among other is aimed to protect water reservoir, wetland of ecological significance (Syed, 1998); however their implementation is fur from optimal. Concluding Remarks: Conservation of wetland is very important from various stands points. But the way in most cases conservation initiatives were taken in the past could be at best termed at command and control/top down approach.
Which not only failed to get the support from the relevant, especially primary stockholders but also created resentment among them. It was primarily because, in the name of conservation without making alternative provision for their livelihood they conservator basically evicted the people dependent on the wetlands. As a result we saw huge/mass protest against the conservation of few flood plain beels and haors which were really reach in critical state due to over exploitation for fishing and indiscriminate use of chemical inputs for agriculture.
Finally it could be said that wetland conservation efforts must be bundled with development scheme which will not only conserve wetlands but also will not undermine the alternative avenues of livelihood for people dependent on wetland in one way or another. References: Syed, A. Sattar . 1998. Introduction to Environmental Laws of Bangladesh. Dhaka: Ace Data Products. BGD/97/017 – Empowerment of Coastal Fishing Communities for Livelihood Security, October 1998 (Draft UNDP project document) Chowdhury, S. Q. ,Haq, F. A. T. M. and Hassan , K. 1992. Coastal geomorphology of St. martin’s Island. Oriental Geographer 36(2): 30-44.
Fattah, 1979. Protection of marine environment and related ecosystem of St. Martin’s Island. Proceedings of the National Seminar on Protection of marine Environment and Related Ecosystems, Dhaka,27-29 November,1979,pp 104-108. Flood Action Plan. Northeast Regional Water Management Project (FAP 6). “Wetland Resources specialist study (final draft), Canadian International Development Agency (CIDA), April 1993. Harvey, W. G. 1992. Birds in Bangladesh. Dhaka: University Press Limited. Hussain, M. G. 1997. “Stock Improvement and Genetic Resource Conservation of Floodplain Fishes. ” In Tsai, Chu-fa and M. Youssouf Ali, Eds.
Openwater Fisheries of Bangladesh. Dhaka: The University Press Limited. IUCN (The World Conservation Union). 1989. A Directory of Asian Wetlands. IUCN, Gland, Switzerland and Cambridge, UK. Khan, Salar M. , et. al. , Eds. 1994. Wetlands of Bangladesh. Bangladesh Centre for Advanced Studies & Nature Conservation Movement. Khan, S. 1998. Genetic Resources. In Bangladesh Environment: Facing the 21st Century. Ed. Philip Gain. Society for Environment and Human Development, Dhaka, Bangladesh. Tsai, Chu-fa and M. Youssouf Ali, Eds. 1997. Openwater Fisheries of Bangladesh. Dhaka: The University Press Limited.