Marine debris invasion and pollution assessment in mangrove wetlands in the northern South China Sea

Abstract Mangrove wetlands as debris traps should receive more attention. Here, we assessed that the magnitude, accumulation, source and fate of marine debris in seven mangrove areas in the north South China Sea (MNSCS) (2019–2020). Marine debris with plastic dominating is invading the MNSCS at the low level. More than 70% of all debris weight with plastics (48.34% ) and fabrics (14.59%) is land-based, and more than 70% comes from coastal/recreational activities. More than 90% of all debris items with plastics (52.50%) and styrofoam(36.32%) is land-based, and more than 90% comes from coastal/recreational activities. The medium/large size debris are trapped in mangrove wetlands under the influenced conditions of local tidal level, debris item materials, and sizes. We expect that our study is helpful to determine the nature and significance of their risk and future marine debris management and the mangrove conservation and restoration.