Saltwater intrusion into freshwater systems, intensified by climate change and anthropogenic activities, poses multifaceted challenges in coastal Bangladesh. This study investigates how thirty years of peer-reviewed research has addressed these challenges, asking: What are the dominant themes in salinity-related research in Bangladesh, and how do they interconnect?

Guided by a combination of systems thinking, socioecological resilience, knowledge mapping, and boundary work frameworks, this study presents a comprehensive systematic scoping review of research on coastal salinity in Bangladesh, aiming to map the breadth of existing literature and examine the interconnections among key research areas. Following PRISMA 2020 guidelines, 231 relevant studies were identified from Scopus and Pubmed. Abstracts were independently coded and categorized into 14 thematic areas, including agriculture, health, livelihoods, water management, climate, ecosystems and pollutants.

Co-occurrence analysis using ATLAS.ti 25 revealed significant thematic overlaps and interactions. Among the themes, crops, human health, and livelihoods emerged as the most dominant, reflecting the direct and immediate impacts of salinity on food security, well-being, and economic stability. From these themes and co-occurrence measurements, this scoping review discusses salinity's drivers, its co-contaminants, and its impacts on ecosystems, land use, livelihoods, communicable and non-communicable disease and agriculture, as well as the diversity and efficacy of water management strategies.

By mapping peer-reviewed research on salinity in coastal Bangladesh, this scoping review offers a holistic and integrated perspective spanning public health, socioeconomic, agricultural and ecosystems research. It provides a structured foundation for future research, guiding scholars in contextualising their inquiries, identifying knowledge gaps, and selecting appropriate analytical frameworks. In particular, the study discusses three complementary frameworks (socioecological systems, vulnerability, and just transition) that collectively address the multifaceted and complex challenge of salinity intrusion in coastal Bangladesh.