Social-ecological interdependencies: Community perspectives on water quality in Chilika Lagoon

Water quality is a critical determinant of ecosystem health, influencing biodiversity, livelihoods, and ecological stability. In Chilika Lagoon, water quality is central to maintaining ecological balance and sustaining small-scale fisheries (SSFs) on which many local communities rely. However, the lagoon has experienced steady water quality decline due to anthropogenic pressures such as shrimp aquaculture, agricultural runoff, industrial waste discharge, and tourism, compounded by natural factors like sedimentation and cyclones. These changes directly threaten biodiversity, habitat health, and the socio-economic well-being of dependent communities. This study investigates the perceived drivers and impacts of water quality changes. A mixed-methods design involving 190 household surveys, 32 key-informant interviews, and three focus-group discussions across three of four lagoon sectors to integrate local ecological knowledge with scientific understanding of water-quality change. The research addresses a key gap in how community-based and traditional ecological knowledge can complement formal monitoring in data-scarce coastal systems. Findings reveal that perceived pollution drivers include aquaculture effluents, agricultural runoff, and waste disposal, resulting in eutrophication, seagrass decline, and reduced fish abundance. Socio-economic consequences include livelihood loss, migration, and health concerns, while governance challenges stem from fragmented institutional coordination and limited enforcement. Despite these pressures, adaptive responses such as modified fishing practices, livelihood diversification, and interest in restoration initiatives demonstrate local resilience and stewardship potential. The paper operationalizes the OneWater framework, showing how integrated water governance and nature-based solutions can enhance ecological recovery and social well-being by linking community perceptions to water-cycle interactions from catchment to coast. The results offer actionable insights for collaborative policy design and participatory water management in tropical coastal lagoons experiencing similar social-ecological stressors.