Fish diversity indices of Hail Haor, a subtropical wetland in the north-east region of Bangladesh: Diversity influencing factors and recommendations

One of the largest wetlands in Bangladesh's north-east, Hail Haor supports a variety of aquatic habitats and has a diversified ecosystem. To ascertain the fish diversity indices of Hail Haor, this study was carried out month by month from December 2020 to June 2021. For this study, three sampling sites in the Moulvi Bazar district—Chiruadobi Beel, Gopla River and Balla Beel were chosen from which fish samples were collected. Twenty-five different fish species were identified and 12,076 fish (individual numbers) were counted and categorized. The Shannon diversity index varied from 1.33 to 1.65. Hail Haor's species diversity index is moderate by the index standard. The Shannon evenness index (E) varied from.41 to.51. The Depressed Community is present in the Hail Haor species diversity index, as per the index standard. The Simpson dominance index fluctuated from.56 to.72. The species diversity index of Hail Haor contains moderate dominance, as per the index standard. With the help of local retailers, fishers, and other relevant stakeholders, the FGD identified factors that have an impact on the diversity index. The current study on diversity indices will be highly beneficial for formulating strategy and managing Hail Haor by strictly adhering to the recommendations.