Rainfall has been reported as an influential source of input, where microplastics concentrations differed in both mass and count with seasonality and the occurrence of storms . Run-off after rainfall introduces microplastics from the land into waterways which flow into the ocean to contribute to the inputs and behaviour of microplastics in coastal areas . For surface water a positive relationship was seen, which suggest high inputs of floating microplastics in coastal areas following rainfall. However, a negative relationship was observed between sediment microplastic concentration and rainfall which is consistent with the reverse trend observed for microplastic concentration in sediment and the proportion of river water at the sampling site.