Changes in Water Areas and Capture Fisheries Production in Hakaluki Haor, Bangladesh: Understanding the Socio-economic Impacts Through Time-Series Analysis

Hakaluki Haor, the largest freshwater wetland in Bangladesh, plays a crucial ecological and socio-economic role by supporting inland capture fisheries and sustaining local livelihoods; however, its morphology and hydrological dynamics have undergone significant transformations over recent decades. This study integrated remote sensing and geographic information systems techniques with time-series statistical analyses to quantify water area changes from 1990 to 2020 and examine their implications for fish production and community livelihoods. Landsat imagery and the Modified Normalized Difference Water Index were applied to assess waterbody dynamics, while Mann–Kendall trend tests, Sen’s slope estimator, Pettitt’s change-point detection, and Spearman correlation were used to quantify long-term trends and structural shifts. Results revealed significant water area changes in Hakaluki Haor between 1990 and 2020, mainly due to erratic rainfall and discharge from transboundary rivers. Fish catch showed a statistically significant decreasing trend (Sen’s slope = −83.68 MT/year, p < .001), while water area exhibited a significant increasing trend (Sen’s slope = 19.55 ha/year, p = .001). Fish catch and abundance in the haor were influenced by a combination of climatic factors and anthropogenic pressure, with a notable decline between 1990 and 2015 associated with erratic rainfall, temperature fluctuation, beel siltation, and excessive use of destructive fishing gears. Change-point analysis indicated significant breaks in the fish production around 2004 to 2005 and near 2015, coinciding with extreme rainfall events ( z -score = 1.25 in 2015), which adversely affected fisher livelihoods, reducing fishing participation, prompting occupational diversification, seasonal migration, and gradual socio-economic transitions. Post-2015, fish catch improved following government-led re-excavation of beels and canals, undertaken in collaboration with non-governmental organizations. Sustainable management of haor wetlands requires restoring hydrological connectivity, mitigating destructive fishing, and strengthening climate-resilient fisheries governance.