Marine debris attribution for remote islands in the western Indian Ocean from global Lagrangian simulations
Noam Vogt-Vincent*, April Burt, Helen Johnson
Department of Earth Sciences, University of Oxford, UK
Department of Earth Sciences, South Parks Road Oxford, Oxfordshire, United Kingdom Pincode: OX1 3AN Mobile: 7435565042 E-mail: email@example.com
Aldabra is a remote atoll belonging to the Outer Islands of Seychelles, and has received World Heritage Site status due to its unique and relatively pristine natural environment. Unfortunately, like many other remote islands in the western Indian Ocean, enormous quantities of marine debris have accumulated at its shores. Assessing the source of this pollution is challenging. Observational and modelling studies have provided valuable insights into the sources of marine debris accumulating at Seychelles but, to date, the relative importance of these various sources remains poorly understood.
We have run sophisticated dispersal models to assess the most likely sources, both terrestrial and maritime in origin, for debris accumulating across Seychelles and other islands in the western Indian Ocean. Our global simulations incorporate the effects of surface currents, waves, and wind, in addition to flexible parameterisations for beaching and buoyancy loss. Our methodology allows us to store results from hundreds of billions of virtual particles with relatively modest storage requirements, which is vital as previous studies with smaller particle numbers have been unable to reach statistically significant conclusions for small islands such as those that comprise Seychelles. The results from these simulations will be valuable for many stakeholders, not only those in Seychelles, but also other small island states in the western Indian Ocean region.