The proliferation of plastic waste, fragmenting into microplastics (MPs) – persistent particles smaller than 5 mm – fundamentally challenges the traditional donor-recipient paradigm of environmental knowledge generation and dissemination across transboundary river systems. In the Brahmaputra Jamuna basin, a vital artery sustaining millions of lives through Bhutan, India, and Bangladesh, MPs migrate seamlessly across political boundaries, embedding themselves in surface waters, riverbed sediments, and the gastrointestinal tracts of fish that form the dietary backbone of riparian communities. This mobility introduces profound uncertainties: upstream glacial melt in Tibet and minimal inputs in Bhutan’s forested highlands give way to urban-industrial surges in Phuentsholing and Guwahati, culminating in downstream flood-driven remobilization in Bangladesh’s deltaic plains. The precise magnitude, timing, and ecological fallout of these contaminants remain elusive, compounded by seasonal hydrological shifts – pre-monsoon stagnation concentrating MPs versus post-monsoon flushing that disperses yet reactivates them.
Scientific modeling provides indispensable predictive tools for long-term mitigation, yet its efficacy hinges on integration with lived experiences from fishers, waste collectors, and rural households whose daily practices shape pollution pathways. Stereotypical interventions – such as blanket plastic bans without alternative livelihoods- often yield maladaptive outcomes: informal dumping persists, eroding public trust and inciting localized resistance. In this nexus of societal needs and ecosystem fragility, adaptive governance emerges as a necessity, weaving participatory learning, iterative feedback, and policy flexibility into decision-making fabrics. This brief adopts a diagnostic framework akin to Soft Systems Methodology, scrutinizing MP governance failures: opaque data flows between nations, siloed institutional mandates, and exclusion of indigenous knowledge in hotspot mapping. Despite these fractures, tri-national stakeholder dialogues – spanning workshops in Bangladesh (February 2025), Bhutan (March 2025), and India (October 2025) – revealed a latent willingness for transformative collaboration, provided equitable platforms amplify marginalized voices from remote Harachhu villages to Sirajganj’s flood-prone chars. These events, employing policy canvass tools, not only disseminated empirical gradients but catalyzed institutional commitments, exemplified by Bangladesh Agricultural University’s immediate campus-wide plastic bottle ban.
