Freshwater aquaculture in the Indian Sundarbans: expansion, challenges, and climate change adaptation

Freshwater aquaculture in the Indian Sundarbans has witnessed significant growth over the past four decades, largely driven by declining agricultural viability due to increasing soil salinization, erratic rainfall, and rising demand for fish protein. This study aims to assess the spatial and temporal expansion of freshwater aquaculture from 1985 to 2024 and evaluate its production outcomes and livelihood implications. Employing a mixed-methods approach, the analysis integrates remote sensing data (Landsat and Sentinel-2 imagery), supervised and unsupervised land use classification, and field surveys involving 350 fish-farming households. Results indicate a 96.9% increase in aquaculture area-from 80.54 km² in 1985 to 860.96 km² in 2024-with growth concentrated in Pathar Pratima, Gosaba, and Basanti blocks. The majority (82.12%) of ponds are small-scale, yielding an average household production of 87 kg and generating ₹13,918 annually, with a mean productivity of 120 kg/ha/year. Labeo rohita and Labeo catla are the dominant cultured species. Despite expansion, key challenges include seed and feed shortages, salinity intrusion, and inadequate infrastructure. Government interventions such as MGNREGS and the Jal Dharo Jal Bharo scheme have facilitated water management and pond development. The findings underscore the need for strategic ecological planning and policy support to ensure the sustainability and climate resilience of freshwater aquaculture in this vulnerable coastal ecosystem.