Nevertheless, the Rams definition has been adopted and being used in Bangladesh. Wetlands of Bangladesh are lassie 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, bells (low-lying depressions in the flood plain), hairs and boors (oxbow lakes) present the inland freshwater wetlands (Khan et al. 1994). The hairs are bowl-shaped natural depressions between the natural levees of the river subject to monsoonal flooding every year.
While the hoar itself is a seasonal water body formed during the monsoon, the bee’s are low-lying depressions of the hoar system retaining water even during the dry months of the season. Thus, the hoar system is a complex of both illustrate and Palestine wetlands depending on the hydraulic behavior in different seasons. The ecology of the hoar system is principally driven by seasonal hydraulics. During the monsoon, he entire hoar system becomes a single body of open water linked to the river system.
When floodwater recedes, the bells 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 hoar 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, delicate 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 wetlands a) Marine permanent shallow waters at low tide, egg bay coral reefs, egg SST Martin’s reef b) Estuarine intertribal mud, sand or salt flats with limited vegetation, egg newly-accreted land intertribal marshes intertribal forest wetlands including mangroves, egg Sandbars c) Lagoon brackish to saline lagoons with narrow connection with sea 2.
Freshwater wetlands) Revering wetlands permanent rivers and streams including some char land, temporary seasonal rivers and streams b) Illustrate atlantes There are thousands of lakes of varying sizes in Bangladesh, the greatest concentrations being in the main delta region covering the districts of Rajahs, Pain, Chula, Josser, Purify, Camilla and National. Palestine wetlands permanent freshwater marshes and swamps with emergent vegetation, permanent peat-forming freshwater swamps, freshwater swamp forest, egg hajji forests of lowland 3.
Man-made wetlands aquaculture ponds (brackish and freshwater) irrigated land and irrigation channels salt pans hydro-dam, egg Captain Lake However, the real 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 Rivers,497 Estuaries and mangrove swamps Bells and hairs 1,142 Undeniable floodplains 54,866 Captain Lake 688 Closed water/Ponds 1 , 469 gars (oxbow Lakes) 55 Brackish-water farms 1 , 080 Total 72,899 source Khan 1994 6,102 Significance of Wetlands in Context of Bangladesh: Wetlands are critically important in Bangladesh for human settlements, biodiversity, fisheries, agricultural diversity, navigation & communication, and costumers. These are discussed in some details in the following sections.
In a land scare country like Bangladesh where average population density is almost 1 000 person per sq . Km people in the marginalia category build their habitat/settlement in the wetland in the event of acute shortage of available high land. Flood plain areas are the treasure-house for rice- the staple food of Bangladesh people. More than 100 varieties, some of which are even deep eater 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 (Tsar, and All, 1997). A part from that, wetlands are valuable sources of food (vegetable), fuel, fodder and traditional declined 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) (Tsar and All, (Deeds). 1997). At any rate, the known levels of endemics in the Ganges/Premature basin are very gig: 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 (Hussein, 1997). Likewise, the estuarine/ marine resources of the Bay of Bengal are part of the world’s largest immunological province. These resources include clams, Oysters, scallops, snails, slugs, chitin, squids, octopuses and some others.
The catchy-fauna of the Bay of Bengal includes about 475 recorded species of fish, 53 of which are cartilaginous and 422 species are bony fish (CNN, 1989). Chowder and Sensually (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 eater 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 hoar 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-Premature floodplain area, about 2. 1 million ha of wetland have been lost to Hood Control, Drainage and Irrigation development projects (FOCI).
Introduction of HOW of rice which requires high inputs like mechanical tillage, chemical fertilizer, insecticide, herbicide, fungicide in fact caused recoverable 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 payday crop only during monsoon season hen 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 isolation of the channels and continuous inundation of land with saline water.
In the hoar areas, large-scale settlement was initiated over the last couple of decades from surrounding densely populated regions and since then the sources of the hoar 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 hoar areas. Similarly, embankment constructed for FOCI projects reduce floodplains and obstruct fish movement and migration from rivers as well as bells to the remaining floodplains for feeding and breeding.
As result, many fishermen have lost their livelihood. However, there have been some positive effects of wetland transformation as ell. The major impact has been on cropping patterns and intensity. Dependence on local boor has been shifted towards HYPE boor. In the FOCI 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 arioso multilateral agencies ( like Workloads, DAB), bilateral agencies (like SAID, DIANA, CIA), intergovernmental agencies, and MONGO (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, SAID/Bangladesh, in injunction with the Ministry of Fisheries and Livestock (Move), 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 (SAID, 2002).
Kisses, DAD in cooperation with the Ministry of Land, Ministry of Fisheries and Livestock (Move), is implementing Community Based Fisheries Management (CUFF). Apart from these II_JAN [at present World Conservation union] is implementing Wetland and Coastal Biodiversity project which has exclusive focus on hoar, and estuarine/marine wetland ecosystem insertion. 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 1 997, Environmental Conservation Rule 2002 (amended) among other is aimed to protect water reservoir, wetland of ecological significance (Seed, 1998); however their implementation is fur from optimal. Conclude inning 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 est.. Termed at command and control/top down approach.