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CHAPTER 2. WETLAND STUDY OVERVIEW
The wetland studies focus on the most important ('key') wetland sites in the region. The rationale for this is:
There are severe constraints - financial, institutional, social, demographic - to improved wetland management. Under these circumstances, it was felt that a strategic approach (focusing on the most important wetlands) would have a greater likelihood of success than a comprehensive approach (preparing basic inventory and baseline data of 'all' the region's wetlands).At the key sites, the investigations address selected wetland taxa - wild wetland plants (macrophytes); waterfowl and wetland-dependent wild birds; other wetland-dependent animals (mammal, reptile, amphibian), and selected aspects of wetland ecology - wetland seasonal changes and local people's dependence on and perceptions of wetlands. The rationale for these selections are:
Other NERP Subteams in Fisheries, Agriculture, Sedimentation, Hydrology/Geohydrology, Social Anthropology, Water Resources, and Economics covered these other aspects of the region. Given this organizational setting, the Wetland Subteam chose to focus its field research efforts on those wetland values (plants, birds, animals, and their seasonal changes and relationships to local people) not being studied by any other NERP subteam, using the wetland system as the reference frame.2.2 OBJECTIVES
The objectives of the wetland field studies were:
The wetland field studies had four components:
Prior information on all but the two best known sites, Hail Haor and Hakaluki Haor, was very fragmentary, and good quantitative data on the basin's waterfowl populations was almost completely lacking. Thus it was felt that the most urgent need initially was for rapid field surveys of the region, covering as many wetlands as possible.
This reconnaissance focused on the importance of the wetlands as habitat for waterfowl, for two reasons. First, the waterfowl of the Northeast Region are of interest in their own right, due to their large numbers and the fact that the basin is part of a major international flyway. Second, waterfowl are often regarded as good indicators of the general ecological status of wetlands, and thus good indicators of the value of sites from the point of view of biodiversity conservation. Absence of large numbers of waterfowl does not however mean that a site has little value. Sites may exist in the haor basin that are of negligible importance for birds but of outstanding limnological or botanical interest (for example, sites with endemic aquatic invertebrates or threatened species of aquatic plants). Detailed limnological and botanical surveys throughout the region would be required to identify such sites.
The evaluation of sites was based on criteria developed in relation to the Ramsar Convention (Tables 2.1a and 2.1b; information taken from the Explanatory Note and Guidelines that accompany the official Ramsar Information Sheet). These criteria, which are now widely recognized as a sound basis for the identification of "wetlands of international importance", are appropriate for use in Bangladesh which became a Contracting Party to the Convention in 1992.
In the absence of any formal criteria for the identification of wetlands of "national importance" in Bangladesh, those sites which narrowly fail to qualify as internationally important wetlands under the Ramsar criteria are regarded as being of "national importance".
Timing of surveys
Two surveys were carried out, one during late winter (dry season) between 18 Feb and 12 Mar 1992 and one during late spring (pre-monsoon period) between 19 Apr and 9 May 1992. These included extensive ground surveys (by vehicle, by boat, and on foot) as well as three aerial surveys, each of two to three hours in duration. Efforts were made to visit as many sites as possible throughout the region, and especially to visit any sites known or rumoured to be of particular importance for waterfowl.
Two surveys is the minimum number needed to assess the importance of wetlands for resident and migratory waterbirds: one during the mid-winter period to assess sites used as wintering areas by migratory species that breed at more northerly latitudes; and another during the main breeding season to assess sites used by resident breeding birds and any breeding summer visitors that spend the winter further south. Also, one of these surveys should be when water levels are at their lowest, to allow critical dry season refuges for waterfowl to be identified, given that water levels fluctuate widely and extensive desiccation occurs during the annual dry season. Finally, it was also clearly important for NERP to conduct a survey during the pre-monsoon period, since many existing and proposed water management projects are aimed at controlling the flash-flooding which occurs at this time. The impact of these projects on the wetlands, their waterfowl, and other wildlife populations is likely to be at its greatest during this pre-monsoon season.
A survey at the time of maximum flooding is usually less important, as at that time there is an abundance of wetland habitat available, the birds themselves are widely scattered, and it is often difficult to pinpoint the important areas.
Fortunately, the two surveys undertaken by NERP met most of these requirements. Wintering populations of waterfowl are still present in the region until early March, and this is the time when water levels are generally at or near their lowest levels. Late spring (the pre-monsoon period) is typically the season of flash-flooding, and is also the time when many of the waterbirds are preparing to breed. Although the main spring migration (Mar, Apr) was largely missed by these two surveys, some early migrants were already passing through the region by the end of the first survey, while a number of late migrants were still present at the time of the second survey.
Surveys at the height of the spring and autumn migration seasons to assess sites used as staging areas for migratory waterfowl, on their way between southern wintering and northern breeding areas, are also highly desirable. These were carried out later, as part of the Monthly Ornithology Surveys (see below).
Most wetlands in peripheral areas of the basin were visited by ground transport. Sixty-three sites, mostly individual beels or small groups of beels, were visited by vehicle, by boat or on foot, 60 of these during the Feb/Mar 92 survey and 51 during the Apr/May 92 survey (48 sites were visited during both surveys). Most of the 12 sites visited in Feb/Mar 92 but not in Apr/May 92 were rather small, isolated and relatively unimportant beels in the Habiganj, Netrokona and Mymensingh areas. Together, these sites held less than 6% of the waterfowl recorded during the Feb/Mar 92 survey.
The aerial surveys focused on the large areas in the deeper, central portion of the haor basin, particularly along the lower Baulai and Kalni Rivers and three smaller areas (a 30 km stretch of the Old Brahmaputra south of Mymensingh, the Chapra and Singai beels east of Sylhet, and Jaor Beel near Sunamganj), which are far from the nearest vehicular access and, by the end of the dry season, inaccessible by boat. These were surveyed by air on 25 and 26 February and again on 9 May in a Cessna 182 on hire from Dhaka Flying Club. Many of the 63 sites visited on the ground were also surveyed from the air. The first day of aerial survey covered the central portion of the haor basin along the lower Baulai River; the second covered the east-central basin along the lower Kalni River to the Sylhet region and also wetlands along the southeastern rim of the basin (Hakaluki Haor, Kawadighi Haor and Hail Haor); and the third, in early May, covered the same areas along the lower Baulai and Kalni rivers, plus the Surma River between Sylhet and Sunamganj, and the important Aila Beel complex.
It had been anticipated that the aerial surveys would locate a number of sites with hitherto unknown concentrations of waterfowl. In fact, very few wetlands of any significance for waterfowl were located from the air. Most of the beels and oxbow lakes in the central part of the haor basin are too small, too widely separated, and too intensively fished and farmed to support waterfowl other than a few egrets and shorebirds. The only significant "new" concentration of ducks located from the air was in Maijeil Haor (Patachatal and Borachatal Beels), where there were an estimated 3,000 ducks on 26 Feb. A ground survey of these two beels on 8 Mar confirmed the presence of 4,180 ducks.
A list of the sites visited and survey itineraries are given in Annex A.
Coverage and limitations
During the two surveys, the investigators were able to visit all of the wetlands known or thought to be of special importance for waterfowl, as well as a large number of sites of only regional or local importance. Special attention was given to the ten sites described in the Directory of Asian Wetlands (Scott, 1989): eight of these were visited during both surveys, and the other two once each (Meda Beel during the Feb/Mar 92 survey and Aila Beel during the Apr/May 92 survey).
Only a tiny fraction of the 6,300 or so beels in the Northeast Region could be visited, but it soon become apparent that the great majority of these were of very little significance for wildlife, and it was felt that few, if any, wetlands of international significance had been overlooked.
The only possible major gap in coverage is thought to have been in the northwest, between the Kaluma Kanda region and the west end of Gurmar Haor. Restrictions on flying within 10 miles (16 km) of the Indian border ruled out an aerial survey, and shortage of time prevented a ground survey. Karchar, Joalbangha, Angurali or Shanir Haors, west of Sunamganj, were not visited during this part of the study; all but Joalbangha were however visited on a casual basis during the Monthly Monitoring Programme surveys, and Kaluma Kanda was visited during the Oct 92 wild life survey.
Coverage of most of the areas was thought to be good; generally greater than 50% and often in excess of 75%. It seems very unlikely that any major concentrations of birds (i.e. numbering in the tens of thousands) were overlooked. Thus, for the conspicuous and easily counted species (e.g. cormorants, herons, egrets, ducks, coots, gulls and terns), it is thought that the counts represent at least 50% and in some cases over 75% of the total present in the region at the time of the surveys.
The counts give only a general impression of abundance for hard-to-count inconspicuous, secretive, or widely dispersed species. These include Little Grebe (inconspicuous), Indian Pond Heron and Cattle Egret (widely dispersed in rice fields), most rails and crakes (secretive and inconspicuous), the snipes (inconspicuous and widely dispersed in rice fields) and many of the smaller shorebirds.
Other habitat types
Although these surveys focused very largely on the wetland ecosystems of the haor basin, some observations were made in the other major habitat types present in the region. In particular, observations were made on numerous occasions in agricultural land (principally rice fields) and homestead forest, both of which constitute very extensive habitat types in the Northeast Region. In addition, brief avifaunal surveys were carried out in two relict patches of tropical evergreen/semi-evergreen forest (West Banugach Reserved Forest east of Srimangal and Shatchari Reserved Forest near Madhabpur), while some casual observations were made in tea estates near Srimangal, and in secondary scrub near Moulvibazar and Srimangal.
Detailed records were maintained of all birds observed at the wetlands and elsewhere in the region, and counts were made of all waterfowl and most birds of prey. Details were also kept of all evidence of mammals, reptiles and amphibians in the wetlands (sightings of live animals, corpses, tracks, and so on). At each wetland, basic information was gathered on the condition of the wetland (water level, aquatic vegetation and surrounding terrestrial vegetation), fishing activities, hunting activities and the general level of disturbance from other human activities.
Waterfowl census data were recorded on the standard waterfowl census forms used by IWRB and AWB in the Asian Waterfowl Census. Examples of these census forms are given in Annex B. The counts made during the late winter survey have been submitted to IWRB for inclusion in the 1992 Asian Waterfowl Census Report and in the Asian Waterfowl Database maintained at IWRB Headquarters in the U.K. Copies of the original count data also remain on file at the NERP offices in Dhaka.
The two principal investigators were Dr. Derek Scott (IWRB/AWB) and S.M.A. Rashid (NACOM). Dr. Scott is primarily an ornithologist with extensive experience in wetland assessment; he is the editor of the Directory of Asian Wetlands, and designer of the Ramsar data sheet. Mr. Rashid (M.Sc. Ecology, University of Kent 1991) has extensive experience in Bangladesh wetlands as both an ornithologist and wildlife biologist with particular interest in herpetology.
2.3.2 Floral studies
The Directory of Asian Wetlands (Scott, 1989) and Aquatic Angiosperms of Bangladesh (Khan, 1987) provide preliminary lists of plants for some of the wetlands of the Northeast Region, but a full account of the region's plants with proper taxonomic identification is lacking.
The objective of the study was to provide a general assessment of wetland plant diversity of the Northeast Region, by studying a variety of sites representative of the complex ecological systems in the region; recognizing in particular the range and importance of human interventions.
Timing of surveys
Five field visits were made every other month from May 1992 to February 1993. During each visit, a set of 19 beel sites in nine different haor systems were visited (Annex A). Staff resources for each visit were 21 person-days or approximately one day per site.
Sample identification and preservation
Most of the plants were identified in the field. Samples of all plants, both those that could and could not be identified in the field, were collected. Two sets of samples were dried, pressed, identified, and preserved in the National Herbarium. Another set of aquatic macrophytes were preserved in formaldehyde, acetic acid, propionic acid, and glycerin mixed with water in various proportions and stored in the NERP field station in Moulvibazar.
Data collection and analysis
In each beel at each visit, the occurrence, abundance and phenology (relations between environmental and biological cycles) of plant species were recorded based on visual estimation. Interviews were conducted with local people regarding utilization of plants. Abundance assessment was subjective, into four abundance rankings:
Quantitative techniques were not used, nor were relationships between vegetation and environmental variables explored. Diversity index and productivity, highly desirable parameters for resource management, were not determined; this would require more rigorously defined quantitative field surveys, and repeated field studies would be required for a high degree of confidence to be achieved.
The two principal investigators were Dr. Ansar Karim (Associate Professor of Botany/Plant Ecology, Chittagong University) and Istiak Sobhan (M.Sc. Botany, Dhaka University). Dr. Salar Khan, founder-director of and honorary advisor to the National Herbarium, provided crucial support in the area of plant identification.
2.3.3 Monthly Monitoring Programme (MMP)
In the wetlands, water levels and patterns of human activity are changing throughout the year. At the same time, each species/community of plant, waterbird, and wildlife has its own requirements for reproduction, migration, and so on. If the objective is to improve the management of wetland biological resources, one requirement is an understanding of the relationships between external conditions and species requirements throughout the year.
Clearly, this is an ambitious undertaking. Intuitively, one would start with the readily observable parameters first. With the resources available, the NERP Wetland/Biodiversity Subteam chose to focus particularly on waterfowl distributions and related data such as water level, disturbance events such as fishing and hunting. Other data (on for example, wild life) was also collected on an opportunistic basis.
Timing of surveys and data collected
Visits were made to 15 wetlands during the last ten days of each month for one full year. As far as possible, the same individuals visited each month, covering the same area. All waterbirds were counted, and all evidence of breeding and migration was recorded. Information was also gathered on the condition of the wetlands (water level, aquatic vegetation), fishing activity, agricultural activity, hunting activity and the presence of other fauna (mammals, reptiles and amphibians). This information and the waterfowl counts was recorded on standardized data sheets (Annex B).
The 15 sites selected for the monthly ornithology/ecology study are listed in Annex A. An indication is given of the nature of each wetland and its status with respect to flood control, drainage and irrigation projects. The criteria for site selection were:
An indication of the effectiveness of the Monthly Monitoring Programme in providing an adequate sample of the waterfowl present in the region has been obtained from the first and third censuses, which took place as part of much more comprehensive waterfowl counts throughout the region. During the Feb/Mar 92 survey, the 15 Monthly Monitoring Programme sites held 66% of the waterfowl recorded during the entire survey, while in Apr/May 92, the corresponding figure was 54%. Clearly, this sample size is sufficient to give a very good indication of the real fluctuations in waterfowl numbers in the region during the course of the year.
Monthly variation in waterfowl population by number of species and number of individuals, in the aggregate, and at each site, was plotted against time. Water level was also plotted as a function of time. Timing of disturbance events (fishing, hunting) was noted and compared to fluctuations in waterfowl numbers.
Waterfowl migration through the region was analyzed -- the arrival and departure of winter visitors, the occurrence of passage migrants in spring and autumn, and the arrival and departure of summer visitors. Breeding seasons of waterbirds in the region were also analyzed. These are known to be complex, with some species breeding during the pre-monsoon period, others during the monsoon, and yet others after the monsoon.
Interesting observations (threatened species and so on) were noted and logged separately.
2.3.4 Wildlife studies
A better understanding of wildlife was required to assess the contribution of this resource to society and to determine the effect of development interventions. There was little information on the wetland wildlife of the region.
Field surveys were undertaken at each of the six key sites during the pre-monsoon , monsoon, and post-monsoon periods. During the field work, information was collected and recorded through observations as well as discussions with local people. In addition, specimens were collected and preserved for later submission to the National Museum. The field information was supplemented with a literature review.
The two principal investigators were Mr. Anisuzzaman Khan and S.M.A. Rashid. Mr. Khan is a wildlife biologist who is also President of the NGO -- Nature Conservation Movement. Mr. Rashid is a wildlife biologist specializing in animal ecology. Both have extensive field experience in Bangladesh.
2.4 METHODOLOGY - VILLAGE-LEVEL PARTICIPATORY STUDY
In January-March 1994, a village-level participatory study was undertaken. Six villages were selected for study, two associated with each of the three threatened habitats (floodplain grassland, reed land, swamp forest). The criteria used in the choice of study villages were a high degree of association (dependence on, involvement with, knowledge of) with a threatened habitat area, and logistical considerations, in particular, accessibility by women field workers.
Field data was collected by a team of men and women social anthropologists from IDEA. Preparation for the study included a one-day training session given by members of the Wetland Subteam, which covered both background material on the wetlands and threatened habitats, and the specific participatory study methods to be used.
The basic approach was for the workers to conduct semi-structured interviews, following a guide sheet of talking points, with village people of varying ages, occupations, economic and social status, and both genders, individually and in groups. Participatory maps were prepared during these interviews, showing the detailed land use pattern within the area associated/controlled by each village visited.
Men workers tended to talk to men informants, and women to women. The women tended to work in pairs, to minimize arousing villagers' negative reactions to women alone in public.
Most of the interviews were recorded, with the participants knowledge and permission, and Bangla notes were also taken. The notes and transcripts were transcribed and translated into English for analysis.
Preliminary results of this work are reported here. CIDA support to complete the analysis and write up the findings is not available. These activities will be completed and the results published with alternative support, if possible.
2.5 STUDY LIMITATIONS
For the most part, the approach described above served us well. A number of limitations, known at the outset or discovered in the course of the study, are recorded here for their value as lessons learned.
Comment: NERP probably underemphasized the developmental importance of water quality, in keeping with the water quantity focus implicit in the Flood Action Plan. The NERP experience suggests that water quality should be given a higher profile in future water sector development efforts.
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