High concentrations of plastic hidden beneath the surface of the Atlantic Ocean

TLDR

Marine plastic pollution is a severe concern, and a mass imbalance between inputs and observed litter indicates a missing sink. The study aims to assess plastic inputs and stocks across all size categories and polymer groups to determine their fate and danger. The Atlantic Ocean interior contains high loads of small plastic debris, with 11.6–21.1 million tonnes of the three most common polymers in the top 200 m, indicating that ocean plastic inputs and stocks are far higher than previously estimated.

Abstract

Abstract Concern over plastic pollution of the marine environment is severe. The mass-imbalance between the plastic litter supplied to and observed in the ocean currently suggests a missing sink. However, here we show that the ocean interior conceals high loads of small-sized plastic debris which can balance and even exceed the estimated plastic inputs into the ocean since 1950. The combined mass of just the three most-littered plastics (polyethylene, polypropylene, and polystyrene) of 32–651 µm size-class suspended in the top 200 m of the Atlantic Ocean is 11.6–21.1 Million Tonnes. Considering that plastics of other sizes and polymer types will be found in the deeper ocean and in the sediments, our results indicate that both inputs and stocks of ocean plastics are much higher than determined previously. It is thus critical to assess these terms across all size categories and polymer groups to determine the fate and danger of plastic contamination.