The fate and concentration of plastic pollutants in coastal seas depends on meteo-oceanographic factors and the multiple entry points in the domain. This will in turn control the implications for water quality, transmission of various biological diseases and the efficiency of recovery. In this paper we shall present a robust numerical model linked sequence that has been prepared jointly by Puertos del Estado and LIM-UPC. It is based on advanced, coupled meteo-oceanographic models that account for the main physical mechanisms responsible for circulation and dispersion. From here concentrations, times of renewal and trajectories can be derived with enough resolution so as to capture the important gradients in topography and bathymetry characteristic of coastal seas. The validation of these forecasts will require suitable data that address the various fields numerically predicted. This includes wind, atmospheric pressure, waves, currents and also the variations in mean water level. Such an observational effort needs also initial and boundary conditions that for dynamically narrow shelfs can shape the water, sediment and pollutant fluxes in the platform. In the paper we shall discuss the nested sequence that has been prepared and is now run pre-operationally for a set of Canary island harbours, where the Plocan data can provide valuable boundary information for model assessments. The simulated current dispersion patterns will be the basis to discuss impacts and recovery policy so as to maintain a water quality status in harbour areas and adjacent coastal tracts that comply with regulations and the requirements of coastal users.