Implications of Micro- and Nanoplastics in the Marine Environment

Microplastics and nanoplastics are small plastic particles that can enter the marine environment through a myriad of different routes, mainly from terrestrial activities such as discharge via waste-water treatment plants, as well as via river networks. Once in the marine environment, particles are transported via wind-driven Ekman currents (surface current caused by interaction between the Coriolis effect and wind) and Geostrophic currents (flow of oceanic water where there is a balance between the pressure gradient force and the Coriolis effect). Particles can sink through the water column, depending on their density and/or the level of biofouling that occurs, to the seafloor. Nearshore resuspension into the water column may occur through anthropogenic disturbance or they remain suspended within the water column, resulting in all faunal size classes inhabiting different marine realms interacting with microplastics and nanoplastics. Particles can be ingested and accumulated within individual organisms and can lead to bioaccumulation and biomagnification through the trophic food web. Studies have found that particle ingestion can damage metabolic activity, impact the immune system, change behaviour, negatively impact reproduction and ultimately reduce survival rates of organisms. Modelling the movement of plastic particles is important in supporting field studies and can help with prediction and monitoring in the environment.