Conservation of a river for biodiversity and ecosystem services: the case of the Halda - the unique river of Chittagong, Bangladesh

The Halda is the only tidal freshwater river in the world where major Indian carps spawn naturally. The river also serves as a source of drinking and irrigation water, a fishing ground and a means of water transportation. We investigated the biodiversity and ecosystem services of the Halda in the context of the conservation of this river in cooperation with river-dependent community and challenges thereof. The primary and secondary field data have been collected from relevant government and non-governmental organizations using both structured and semi-structured questionnaires. According to our calculations, the total economic worth of benefits derived from provisioning services of the Halda was approximately BDT (Bangladesh Taka) 1753 million. Irrigation and drinking water were the major contributors with BDT 1333 and 122 million, respectively. Carp spawning has lower primary economic worth (BDT 10 million) but it has a much bigger impact, as it supplies fish fries to the whole country. The river supports temporary and permanent livelihood for egg and fry collectors (approximately 2000), fishermen (approximately 350), boatmen (approximately 250), boat building and mending (approximately 150), sand quarrying (approximately 760), which creates a cumulative worth of BDT 283 million. The sustained flow of provisioning service from the Halda explains the willingness to contribute money (54 million) and time (average 6.6 hours/month) by local communities for conserving this river. Half of the respondents, though illiterate, have shown genuine concern about the future of the river. The sustainable flow of services and enhancement in their economic output require conservation and scientific management of the Halda. The community willingness and its dependence, as unearthed by our research, provides compelling ground for community-based conservation and management of the river. Future conservation projects and management plans for this river should involve local communities to avail their willingness to conserve this river while sustaining their livelihood through enhancement of economic output from it.