Plastic input, transport, and fate in the ocean

Understanding the input, transport, and fate of plastic debris in the oceans is crucial for quantifying the exposure in different ecosystems as well as informing regulatory and mitigation efforts. From early days of plastic research studies have focused on resolving the mass balance of plastic, with parallel efforts constraining the input of plastic debris and estimating the mass present in different environmental compartments of the ocean system. Since both the input and distribution of plastic debris is heterogeneous and the sampling of plastic—especially microplastic—is difficult, understanding and modeling plastic transport is required to predict the abundance of plastic. In this chapter, we cover the history of studies of the plastic mass balance and the evolution of estimates of input and plastic mass in the environment. Important transport processes are discussed with an emphasis on how those processes distribute plastic to different environmental compartments.