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Study on the ecology and benthic status of the river Halda

To explore and understand the present state-of the art of the river Halda with particular focus on the underwater river environment and aquatic life within a short span of time, the present study will try to attend the following objectives.


  • To understand the ecological features and  underwater bio-physical characteristics of the river
  • To study the  occurrence and composition flora and fauna  of   river
  • To identify the Kum (Duars) with noting its bio-physical  features
  • To identify the threats in terms of natural and human-induced changes
  • To suggest long term protection, conservation and sustainable uses measures of river biodiversity and biological resources.


Rivers and wetlands are major ecosystems supporting habitat of massive biological resources, wild flora and fauna, sources of fossil fuels, biofuels and hydropower. Wetlands are the foundation pillar of rural economy as a result of its highest biomass productivity, source of domestic and industrial water needs, role as ground water recharge and discharge,  water reservoir and pollution abatement .  Wetlands   water regime in this country are intricate  and diverse networks of oxbow lakes, bowl-shaped depression, low-lying islands, floodplains, lakes, reservoirs, streams, springs, swamps, canals, ponds ,inter-tidal mudflats, creeks, estuaries and mangrove swamps are producer of ecological water and the vast natural renewable resources including zoo plankton phytoplankton, algae, macro benthos,  hundreds of species od aquatic Coelenterate, Porifera, Nematodes, Helminthes, Mollusks, Crustaceans, Arthropods, Fish, Amphibians, Reptiles, Aves and Mammals. The wilderness of the rivers are inbuilt in its vast courses with the natural diversity in biome, ecosystems and genomes originated, evolved and distributed along its tributaries, distributaries and associated wetlands . River, rivulets and wetlands those are the lifeline of people’s social, economic and cultural life.

The beauty and bounty which are engraved in each and every meandering of the river runs from hills to the sea are the main attraction of river tourism from time immemorial. People of this region are great river traveler and their culture and livelihoods are deeply rooted with rivers and water. Historically, the civilization in this delta is built on the bank of rivers. “ Bandars”  (ports)the trading hubs  were all located on the bank of rivers. But those river borne heritages is now a days are history. Flooding of the rivers during the monsoon season causes enormous hardship and hinders development, but fresh deposits of rich silt replenish the fertile but overworked soil. The rivers also drain excess monsoon rainfall into the Bay of Bengal. Erosion and accretion are two major characteristics of our rivers which are causing severe natural hazards to the people living on the bank of river. Thus, the great river system is at the same time the country's principal resource and its greatest hazard. Although there exists policies, masterplans ,strategies and action plans pertaining to water, river, wetlands and aquatic biodiversity   ( NBSAP, NCS, NEMAP,BCCSAP,  Ramsar, CMD, CMS, SDGs 14 & 15) but its implementation is lagging far behind as result the rivers are dried up, wetlands are drained and land filled,  , encroached , heavily polluted and finally dead. Holistic thought about river is a naturally evolved biome and integrated approach for renewable natural resources management is one of the remedy to sustain the renewability and continuity of river and wetlands productivity for both nature wellbeing and human wellbeing. Priority need is to Paradigm shift from river- backyards theme of dumping grounds to river—front development for better environment. This study will provide a state-of-the art report of the river and wetlands ecosystem of Haldariver and suggest the ecosystem—based management approach for maintaining the renewability of the natural aquatic resources for sustainable development.

Scope of Work

Environmental Flow Assessment, Development of a Public-Private Partnership Model and Benthic Study to Assess the Status of Ecology of Halda River

Study Area

Halda River in Chittagong


A five memberedIsabela team comprised of underwater explorer (Scuba diver) and River ecologist and Field biologists will conduct the survey with support from other associated team members of this project.  The members are well trained and skilled in diving having certification in professional diving from both home and abroad.

The survey will cover all habitats and ecosystems of the project site including Channel, tributaries, Estuary, Wetlands,charlands and swamp. Random Meander Method will be used for plant species richness data collection.  In this method, researchers will walk in a random manner throughout the selected transect sites, recording all species observed in various vegetation communities

Four vertebrate classes (mammals, birds, reptiles and  amphibians ), and vascular plants are selected for this study because they are (i) mostly well-known and of general interest to scientists and managers; (ii) relatively easy to identify, survey systematically and monitor, (iii) important for monitoring changes in the environment over time and (iv) are of value to protected area management. In addition, selected terrestrial and especially aquatic invertebrates taxa are also surveyed due to their presumed importance as indicator species of ecosystem health. Existing and previous land cover (LC) maps developed using satellite imagery to quantify the changing pattern. Sample locations of different flora and fauna shown on the maps (using GPS values) from which habitat boundaries and possibly some species’ ranges determined, 

The study will follow survey protocol, including:

●Internationally recognized techniques followed throughout the Biodiversity Baseline Survey i.e.

Sample sites (e.g., transects or Zig-Zag line, quadrats, blocks and plots) marked using GPS;

●Vertebrate groups survey in each of the selected habitats within the project impact areas;

●Herpeto-mammalian faunal species will be recorded on standard field data forms and transferred to a database and the photo of the recorded species will also preserved.

•Transect lines along the bank of the river to estimate the population of diurnal and nocturnal amphibians, reptiles and mammals.

•Photography for taxonomic confirmation and flashing for nocturnal animals

•Habitats evaluation by analyzing terrestrial, aquatic and vegetation covers and other parameter of all habitats.

•Interview of people about the availability of wildlife diversity, in the project areas.

The available animals of the study areas will be recorded and classified in the following ways;

•Categorized   lists of wildlife fauna (e.g. Amphibians, Reptiles and Mammalians) will be grouped as seasonal categories.

•Relative abundance of individual species of wildlife will be made;

•Habitat types of individual species of wildlife will described and

•Fauna will categorized by CITES schedule and IUCN global and regional criteria.

The description of relative abundance of each species is as Very Common (VC): 80%-100% frequency of occurrence in field visits; Common (C): 60%-79% frequency of occurrence in field visits; Fairly Common (FC): 40%-59% frequency of occurrence in field visits; Few (F), or ‘Rare (R). Species threatened status was categorized as  Vulnerable (VU), Endangered (EN), Critically Endangered (CR), Lower Risk (LR), Data Deficient (DD) followed by the  guideline of  Red Data Book of IUCN-Bangladesh 2000.

Survey of birds will be  carried out through conducting field survey by employing different bird survey methods such as transact line sampling, point sampling, time sampling methods, opportunistic survey and zigzag survey, and focus group discussion methods.

Invertebrate fauna of the project area will be collected through visual enumeration and random sampling

Vegetation data will be collected through sampling of both terrestrial and aquatic habitats of the river.

Description of Ecosystems

For learning the state of rivers ecology following data will be collected through following the standard data protocol. Major ecosystems and ecological niches will be considered as follows.

River Channel

  • River Channel
  • Hill Streams/canals
  • Distributaries
  • River Bank
  • Wetlands
  • Duars (Kum)
  • Islnds/Charlands and
  • Reedlands


Notes on Threats

  • Notes on Threats
  • Natural
  • Erosion
  • Siltation
  • Human-induced
  • Pollution
  • Over fishing
  • Encroachment