Three-dimensional numerical modelling of transport, fate and distribution of microplastics in the northwestern Arabian/Persian Gulf

Marine plastic litter has been a major concern over the past decade particularly in semi-enclosed seas such as the Arabian/Persian Gulf, which are likely to impose a relatively higher threat to ecosystem and human health. In this work, we have focused our efforts on the transport features of marine surface microplastics (MPs) in the Gulf. The assessment utilizes a 3D hydrodynamic model of the northern Gulf which was coupled with a particle tracking model. We have considered five release locations and investigated two dominant wind conditions by applying different numerical scenarios. The results revealed that the northerly winds result in high dispersion and seaward transport of MPs in the open coastal zones, while in semi-enclosed regions they result in high trapping and beaching verified by visual investigation. The study shows that further detailed field investigations are warranted to enable the models to better parameterize the fate and distributions of MPs.