The state of marine debris and microplastic research in India: Bridging knowledge gaps for robust marine litter policy

The escalating global concern surrounding the pervasive issue of marine debris and microplastic pollution in marine environments has been well reflected in India, with marine plastics representing the most frequent persistent materials abundant in the ecosystems and biota. This citation analysis attempted to identify the most frequently cited studies, seminal works, sources, distribution, status and concentration of marine debris and microplastics in the Indian coastal ecosystem and the status of the Clean-Coast Index (CCI) based on the 176 peer-revied papers in Scopus (2013–2023) on marine debris/microplastics. This review further provides an analysis of the assessment of microplastics (MPs) in the marine ecosystem of India, including sources, sampling methods, isolation, characterization, identification, abundance and impacts of microplastics in aquatic life, and the marine litter policy gaps. Reports from the east coast of India are higher in number compared to the West coast during the period, and CCI results indicate that the east coast of India is more polluted than the west coast (extremely dirty > moderate > dirty > clean). The knowledge gap areas identified include the ecological impacts of plastics in the marine environment, the lack of studies on emerging areas such as ‘plastisphere’, and the impacts of marine debris and its chemical contamination on marine biodiversity and chemical contamination. In this evidence-based synthesis of knowledge, we invigorate the discussion on a policy framework for managing marine debris in Indian coastal waters, following global models and commitment to mitigate the impacts of marine litter and microplastics, upstream and downstream management interventions, including promotion of a circular plastic economy and clean production technologies that foster a sustainable coexistence between the developmental needs of worlds' one of the populous country and emerging economy and greening the blue oceans around it.