Abstract
Transboundary freshwater fish are critical for both biodiversity and community well‐being but face alarming overexploitation in shared rivers. Such rivers greatly aid the livelihood and nutrition of local people on both sides of shared borders. However, a lack of understanding of resource dynamics and utilization patterns hinders sustainable management of resources. We investigated spatiotemporal fish assemblages along the River Atrai, a transboundary river between India and Bangladesh. The socioeconomic status of fishers was quantified from personal interviews and group discussions to estimate the exploitation trajectory of piscine resources. Fish assemblages varied significantly among locations and seasons. Species diversity was highest downstream and lowest upstream. Spatiotemporal fishery exploitation aligned with fish diversity among sites and seasons, with fishers preferring to fish in downstream areas during the post‐monsoon season. Fishers were economically weak, with limited sources of income. Therefore, adequate integrated management plans should be implemented to ensure resource resilience in a transboundary pocket, sustainably supporting the livelihood of concomitant fishers.