Estimating the total oceanic plastic content at the end of 2010.
Summary
The existence of regions in the ocean with a high plastic concentration is considered to be a substantial environmental problem. Although there are already initiatives for an ocean cleanup, adequate estimates of the total surface plastic content are lacking. The main goal of this study is to determine an estimate of the total quantity of the plastic debris in the surface ocean at the end of 2010. We combine results from waste data, an emission model and ocean tracer motion computations with the available observations to estimate parameters in the emission model. We also investigate whether representations of sinks of plastics, such as through biofouling, can improve the quality of the correlations between modeled and measured plastic concentrations. Our best estimate is that at the end of 2010, the total quantity of plastic that was present in the surface ocean was 7.4 ± 4.9 million tons.