Tanguar Haor (TH), an ecologically critical area (ECA) and a Ramsar site of worldwide significance, is an essential wetland ecosystem for the Bangladesh’s economic, ecological, social, and cultural aspects. Fish, aquatic plants, amphibians, reptiles, birds, and mammals are notable among the floral and faunal compositions found in this haor. Unfortunately, unsustainable exploitation of its natural resources poses a serious threat to the TH ecosystem. Therefore, the broad objective of this study was to review the status of fish biodiversity along with the driving factors of biodiversity loss and the management issues of the TH ecosystem. A total of 143 species of fishes (137 indigenous and 6 exotic) under 35 families, and 12 orders were documented during the last two decades. Species diversity of the haor has been changed over time due to the effects of climatic, anthropogenic, socioeconomic, and policy related drivers. Furthermore, high dependency on fisheries resources, poverty, and the lack of empowerment to manage the TH fishery were responsible for fish diversity decline. Therefore, ecosystem based co-management through active participation of local community, establishment of balanced fishing tactics, and strengthening alternative livelihoods for highly depended poor harvesters are strongly recommended for the proper management of this valued wetland ecosystem. Furthermore, this review proposes immediate and useful conservation initiatives for the studied wetlands, including comprehensive stock assessment, establishment of gene banks and fish sanctuaries, a combination of input and output control, and regulation with the ECA and RAMSAR guidelines.

Sanctuaries are widely regarded as a protected area where fishing has been placed under some restrictions by local, state, regional and national authorities for the conservation and management of fisheries resources. These sanctuaries have a broad array of positive and negative social, economic, cultural and political impacts on fishers. This study aims to analyze the socio-economic and ecological benefits and costs of hilsa sanctuaries to protect single most important hilsa species using Sustainable Livelihood Approach (SLA). Under the Protection and Conservation of Fish Act of 1950, six sites along the Padma, Meghna, Tetulia, and Andharmanik rivers have been designated as hilsa sanctuaries. Findings of the current study revealed that most fishers perceived production of hilsa and other species were increased as a direct consequences of sanctuaries establishment. However, a considerable proportion of hilsa fishermen was found to have low socioeconomic capital, as measured by monthly income, housing circumstances and asset ownership. During the restricted fishing season in the sanctuaries, these households are particularly vulnerable to food insecurity. The government’s compensation scheme is a good example of payment of ecosystem services in an open water fishery; however, this scheme does not include all the affected fishers. It is found that hilsa sanctuaries lead to income loss of the poor fishers which is insufficiently compensated by government support program. To compensate income loss, fishers resort illegal fishing which undermine the success of sanctuary. If the sanctuaries are to function effectively, affecting fishers must be addressed by offering enough compensation schemes so that fishers are able to support their families. Moreover, some fishers believed that a co-management approach involving fishers and government is the possible best management option for operating sanctuaries in a sustainable way.

The present study aimed to delve into the local ecological knowledge of fisheries in the Meghna River Basin (MRB) of Bangladesh by exploring the insights and perspectives of local communities. A survey was administered among six fishing communities from five districts along the MRB between August 2015 and January 2016 to accumulate data for this study. The study sites were selected meticulously based on three crucial criteria: upstream river, coastal area, and fish sanctuaries, which covered three major rivers, namely the Meghna, Andharmanik, and Payra. The study employed participatory rural appraisal (PRA) tools, including 120 individual interviews using purposive sampling, 25 focus group discussions, and 36 key informant interviews. The study identified the ten most frequently caught fish species along with their temporal and spatial variation as reported by the respondents. Nine of these species fell into the least concern category, which indicate their stable population status. Meanwhile, six out of ten species cited as highly caught in the previous one to two decades belong to the threatened or near-threatened category. Findings also reveal that fishers are able to recognize important microhabitats of the study area and their significance for fish species. In addition, fishers identified the negative drivers of ecosystem degradation as well as suggested several management measures to address these challenges. The results of this study underscore the critical role of engaging with local communities and integrating their ecological knowledge into initiatives for the sustainable exploitation and conservation of aquatic resources in the MRB.

Rivers have been the most important freshwater resource, and our ancient civilizations have flourished along the banks of rivers. River water finds multiple uses like agriculture, industry, transportation, aquaculture, and public water supply. Natural waters are being contaminated as the quality of water is being affected by anthropogenic activities, in developing countries like Bangladesh. From the point of view, the physicochemical parameters (water temperature, pH, electrical conductivity, total dissolved solids, DO, BOD, alkalinity, total hardness, nitrate) of seventeen rivers in Bangladesh were reviewed from January 2021 to June 2021. The water quality parameters of some rivers were found to be far above the suitable limits, which is dangerous for human health, agriculture, and fisheries. It is therefore necessary to check the water quality at regular interval of time to conserve the natural ecosystem of the rivers of Bangladesh. Furthermore, this study would help to create and develop awareness among the people to help maintain the quality of the river waters.