Size Dependent Transport of Floating Plastics Modeled in the Global Ocean

Abstract

Plastic has been detected in the ocean in most locations where scientists have looked for it. While ubiquitous in the environment, plastic pollution is heterogeneous, and plastics of varying composition, shape, and size accumulate differently in the global ocean. Many physical and biological processes influence the transport of plastics in the marine environment. Here we focus on physical processes and how they can naturally sort floating plastics at the ocean surface and within its interior. We introduce a new open-source GPU-accelerated numerical model, ADVECT, which simulates the three-dimensional dispersal of large arrays of modelled ocean plastics with varying size, shape, and density. We use this model to run a global simulation and find that buoyant particles are sorted in the ocean according to their size, both at the surface due to wind-driven drift and in the water column due to their rising velocity. Finally, we compare our findings with recent literature reporting the size distribution of plastics in the ocean and discuss which observations can and cannot be explained by the physical processes encoded in our model.

Plastics as Non‐Toxic Disruptors of Aquatic Ecosystems

“…Nonetheless, plastics that are already in the environment are likely to persist for centuries. Sophisticated modeling studies are increasingly able to predict where microplastics accumulate in lakes (Tanentzap et al 2021), rivers (Lebreton et al 2017), and the oceans (Chassignet et al 2021; Klink et al 2022) to target the treatment of the downstream symptoms of our addiction to plastics.…”

Limnology and Oceanography Bulletin Volume 32 Number 4 November 2023 125‐155

“…Nonetheless, plastics that are already in the environment are likely to persist for centuries. Sophisticated modeling studies are increasingly able to predict where microplastics accumulate in lakes (Tanentzap et al 2021), rivers (Lebreton et al 2017), and the oceans (Chassignet et al 2021;Klink et al 2022) to target the treatment of the downstream symptoms of our addiction to plastics.…”

Impact of Water Level Fluctuation on Microplastic Transportation and Redistribution in a Floodplain Lake System

“…Therefore, a particular consideration was given to the properties of particles. For example, there have been several size-dependent models, in which both the fragmentation processes and individually varying size, shape, and density are in relation to mechanical forces exerted on the plastic debris [40,41]. Although, as shown in Table 1, an increasing number of researchers have realized the importance of microplastics and have fostered numerical simulations to quantify microplastic transportation in recent years, the interaction between microplastics and their adjacent environment is still far from being elucidated.…”