Turning Brackish: Salinity-Driven Mangrove and Fisheries Decline in the Bangladesh Sundarbans.

Reduced freshwater inflow from the Ganges, driven by upstream abstraction and regulation, has intensified salinity intrusion into the Bangladesh Sundarbans, threatening its biodiversity and livelihoods. This study quantifies how salinity exceeds physiological tolerance thresholds for high-value mangrove species like Heritiera fomes (Sundri), causing a 40% decline in suitable habitat while salt-tolerant but lower-value Excoecaria agallocha expands. Analysis of hydrological records, forest cover data, and fisheries statistics from 1996 to 2016 reveals a 54% drop in fish species richness at Mongla market and accelerating ecosystem degradation. Climate projections to 2050 confirm irreversible losses under current trends unless institutional reforms address Ganges water-sharing. The findings underscore the critical need for upstream freshwater management to sustain biodiversity and the livelihoods of 2.7 million dependent communities.

Imtiaz, A., Irfan Sakib, B., & Faria, A. (2026). Turning Brackish: Salinity-Driven Mangrove and Fisheries Decline in the Bangladesh Sundarbans. Zenodo. https://doi.org/10.5281/ZENODO.20089071