Abstract

Malnutrition remains a major public health challenge in Bangladesh: in 2023, 28% of children under five were stunted and 10% wasted, while anemia and iron deficiency were widespread among pregnant women. For poor coastal communities, fish is a critical source of protein and micronutrients. Rising river salinity—driven by sea-level rise and upstream freshwater reductions—is altering fish species composition and reducing access to freshwater fish.

This study examines how salinity affects fish catches (kilograms) and prices (BDT per kilogram) in southwest Bangladesh. We use daily salinity data from five river monitoring stations, ranging from 0.06 ppt to 12.75 ppt (with maximum values ranging from 0.23 ppt to 12.75 ppt), and 832 daily observations of 29 fish species from five wholesale markets. Econometric analysis shows that changes in salinity differentially affect species availability based on their tolerance, already established in the literature, and influence fishers’ adaptive harvesting strategies.

Our findings indicate that salinity-driven ecological shifts are impacting local fish availability, income, and child nutrition outcomes. Integrating observed catch data with species-specific salinity tolerance can improve projections of future fish supply, providing essential information for nutrition and climate adaptation strategies.

This work is licensed under a Creative Commons Attribution 4.0 License.