Bayesian inference of river plastics in the South Atlantic Ocean

This work was published in Frontiers in Marine Science with a “Attribution of Plastic Sources Using Bayesian Inference: Application to River-Sourced Floating Plastic in the South Atlantic Ocean (2022)” by C.M. Pierard, D. Bassotto, F. Meirer and E. van Sebille.

Description

We developed a Bayesian inference framework to determine the probability that a piece of floating plastic found at sea came from a particular river by combining river emission data with Lagrangian simulations. The framework was tested in the South Atlantic Ocean, showcasing that particle age and location define the source probabilities.

Plastic emitted from principal rivers (clustered)

Figure 1: On the left the we show the main clusters of rivers emitting plastics in the South Atlantic. On the right, the percentage of plastic emitted from each cluster.

Lagrangian Simulations of plastic from river deltas

Video 1: one-year continous release of particles from the main river clusters in the South Atlantic. We released 100,000 particles per cluster.

Posterior probability

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Figure 2: Posterior probability maps, averaged over 3.4 years, showing \(p(R_i|S_{loc})\), the probability of finding a particle from a specific cluster at any point in the South Atlantic. Each map displays the probability for a specific cluster in all the bins of the domain. The red dots indicate the locations of the clusters from which the particles entered the ocean. At each location, the sum of posterior probability of the twelve clusters is 1.