Modelling the cleanup of the North Pacific Garbage Patch based on 3 years of operational experience.

Ending plastic pollution in the marine environment requires reducing the sources, preventing the plastics from entering the ocean, and removing the persistent legacy pollution accumulated in areas such as the North Pacific Garbage Patch (NPGP). This study assesses the feasibility and costs of collecting plastics accumulated in the NPGP during a 10 year-period, starting in 2027. The cleanup method consists of a fleet of U-shaped net systems towed behind two vessels funneling the plastic towards a retention zone which is periodically emptied. The background plastic mass concentration at the surface is based on a dispersal model calibrated on the results of field operations, and specifically on measurements performed during 72 collection periods which, between August 2021 and November 2024, led to the removal of a cumulated mass of 372,733 kg of plastics. The study evaluates the impact of the number of cleanup systems, the growth of the mass of plastics in the NPGP, the system’s retention efficiency, and how the systems are steered through the NPGP. Cost estimates are derived from vessel types, market rates, and past operational expenses. Results indicate that, after a decade, more than 80% of the total mass of plastics (> 1.5 cm) of the NPGP baseline can be eliminated, with up to 180 kt of plastics removed from an area covering an average of 1.6 M km2. This target could be reached at a cost of €1.8 billion in an optimal scenario, representing a negligible fraction (< 1%) of the value of the ecosystem services threatened by plastic pollution in this oceanic region for the next century.