Taking a mass-balance approach to assess marine plastics in the South China Sea

The South China Sea (SCS) is recognised as a global hotspot for plastic pollution. We review available field studies and identify a significant lack of data needed to construct a simple mass balance box model for plastic pollution in the SCS. Fundamental information on plastic mass input, transfer and sink terms are simply not available. Also unknown are the rates of accumulation in different environments, the dispersal pathways of plastic particles of different density, the residence times of plastic in the water column and the rate at which macroplastics are transformed into microplastics in different environments. Filling these information gaps is critical for states to determine adequate response measures, including developing and tracking impact of policies to deal with the problem of plastic pollution in the SCS.