Multiple negative impacts of marine plastic pollution on tropical coastal ecosystem services, and human health and well-being

There is limited empirical evidence showing the impacts of marine plastic pollution on ecosystem services or on human health and well-being in Global South countries. We aimed to estimate these impacts in the tropical archipelago of Indonesia, one of the top emitters of marine plastics globally, through an iterative Delphi survey, with an expert panel (n = 42) consisting of equal numbers of Indonesian scientists, policymakers, and practitioners. After two rounds of the survey, the analysis of interquartile ranges indicated that the experts reached a consensus in their predictions. The experts agreed that, over the next 10 years, plastics would be mainly accumulated in the coastal area of Java, the most densely populated island, and mostly in mangrove ecosystems. While all ecosystem services were harmed by plastic pollution, the most vulnerable services were food provisioning, genetic materials, nursery habitat, and recreation supplied by the highly vulnerable coastal ecosystems of, in descending order, mangrove, coral reef, seagrass, and sandy beach. These impacts on ecosystem services influenced different dimensions of human health and well-being and were dependent on the ecosystem types, as indicated in several statistically significant positive correlations (Spearman's rank), including those between the decline of mangrove ecosystem services and reduced household income, and between the decrease of coral reef ecosystem services and both deteriorating mental health and reduced household income. Overall, this study provides the first indication of Indonesian coastal ecosystems and ecosystem services to be prioritized for mitigation and monitoring efforts. The focus on impacts on human health and well-being also incentivizes ongoing efforts by policymakers, industry and commerce, the third sector, and the public in the country to address the contribution to global marine plastic pollution.