EXPERIMENTAL STUDY OF MICROPLASTIC PARTICLE TRANSPORT AROUND SEA GRAVEL IN WAVES PLUS CURRENT CONDITIONS

Microplastics (MPs) are considered to be potentially the most harmful plastic fraction in the ocean (Law and Thompson, 2014). Guler et al. (2022) examined the transport of non-buoyant MP particles beneath irregular breaking waves over a live sediment bed in extended test durations. They identified that accumulation hotspots were largely governed by the particle Dean number. Larsen et al. (2023) developed an approach based on wave-induced transport velocity to predict the onshore transport of buoyant MP particles across a coastal profile. In the present study, we further this research to experimentally investigate the potential retention of MPs under the effects of combined (non-breaking) irregular waves and current in coastal waters by gravel patches having various coverage density.