Accumulation of microplastics in mangrove ecosystem: source, properties, and impacts for conservation

Abstract Mangroves, also called blue carbon ecosystems, are crucial as carbon sinks and in climate change mitigation. However, these ecosystems become vulnerable due to plastic pollution, particularly microplastics. A synthesis of studies across Asia, South America, and North America demonstrates that the microplastic contamination in surface waters and sediments is widespread. Fibres and fragments originating from polypropylene (PP) and polyethylene (PE) are prevalent globally, indicating inputs from textile, fishing, and packaging. Seasonal and spatial changes demonstrate greater loads during pre-monsoon periods and in downstream estuaries. The depth-profile analyses indicate that microplastics are buried in mangrove sediment on a long-term basis, supporting their role as long-term sinks. Microplastics have also been found in mangrove species, including fish, crabs, and bivalves, raising concerns about trophic transfer and food security. The accumulation of microplastics is emerging as a factor connected to changes in microbial communities and reduced carbon sequestration potential. Established protocols and policy integration based on mangroves are required to enhance the conservation policies and ensure the ecosystem services.