A growing plastic smog, now estimated to be over 170 trillion plastic particles afloat in the world’s oceans—Urgent solutions required

PLOS ONE RESEARCH ARTICLE A growing plastic smog, now estimated to be over 170 trillion plastic particles afloat in the world’s oceans—Urgent solutions required Marcus Eriksen ID1*, Win Cowger2,3, Lisa M. Erdle1*, Scott Coffin4, Patricia VillarrubiaGómez5, Charles J. Moore3,6, Edward J. Carpenter7, Robert H. Day8, Martin Thiel9,10,11, Chris Wilcox12 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 1 5 Gyres Institute, Los Angeles, California, United States of America, 2 University of California Riverside, Riverside, California, United States of America, 3 Moore Institute for Plastic Pollution Research, Long Beach, California, United States of America, 4 California State Water Resources Control Board, Sacramento, California, United States of America, 5 Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden, 6 Algalita Marine Research and Education, Long Beach, California, United States of America, 7 EOS Center, San Francisco State University, Tiburon, California, United States of America, 8 ABR, Inc.– Environmental Research & Services, Fairbanks, Alaska, United States of America, 9 Facultad Ciencias del Mar, Universidad Católica del Norte (UCN), Coquimbo, Chile, 10 Center for Ecology and Sustainable Management of Oceanic Islands (ESMOI), Coquimbo, Chile, 11 Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile, 12 Minderoo Foundation, Perth, Western Australia, Australia * (ME); (LME) OPEN ACCESS Citation: Eriksen M, Cowger W, Erdle LM, Coffin S, Villarrubia-Gómez P, Moore CJ, et al. (2023) A growing plastic smog, now estimated to be over 170 trillion plastic particles afloat in the world’s oceans—Urgent solutions required. PLoS ONE 18(3): e0281596. https://doi.org/10.1371/journal. pone.0281596 Editor: Judi Hewitt, The University of Auckland City Campus: University of Auckland, NEW ZEALAND Received: January 12, 2022 Accepted: January 26, 2023 Published: March 8, 2023 Copyright: © 2023 Eriksen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All data from the Plastic Marine Pollution Global Dataset, Modeling code, and Trend Reversal data are available open source at github.com. https://github.com/ wincowgerDEV/ocean_plastic_modeling. Funding: ME received funding from the Baum Foundation to support expeditions and sample collection (http://thebaumfoundation.org/). MT was supported by the European Union’s H2020 Abstract As global awareness, science, and policy interventions for plastic escalate, institutions around the world are seeking preventative strategies. Central to this is the need for precise global time series of plastic pollution with which we can assess whether implemented policies are effective, but at present we lack these data. To address this need, we used previously published and new data on floating ocean plastics (n = 11,777 stations) to create a global time-series that estimates the average counts and mass of small plastics in the ocean surface layer from 1979 to 2019. Today’s global abundance is estimated at approximately 82–358 trillion plastic particles weighing 1.1–4.9 million tonnes. We observed no clear detectable trend until 1990, a fluctuating but stagnant trend from then until 2005, and a rapid increase until the present. This observed acceleration of plastic densities in the world’s oceans, also reported for beaches around the globe, demands urgent international policy interventions. Introduction Understanding the occurrence and trends of plastic abundance in the world are foundational to assessing current and potential future risks to humans and ecosystems [1]. Modeling plastic pollution’s fate and transport in the ocean surface layer (OSL) is complicated by complex mechanisms of degradation, fouling, and turbulent transport [2]. Fragmentation of large plastic results in micro- and nanoplastics leaving the OSL to shoreline and seafloor compartments, where they may cause harm to organisms through ingestion [3]. While recent modeling efforts PLOS ONE | https://doi.org/10.1371/journal.pone.0281596 March 8, 2023 1 / 12 PLOS ONE 170 trillion plastic particles are afloat in the world’s oceans—Urgent solutions required research and innovation programme MINKE project (under Grant Agreement No 101008724). These funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist. suggest rapid export of plastic pollution away from the OSL [4], inputs are likely to continue [5, 6]. Therefore, understanding trends in regional and global plastic pollution mass and abundance is essential to evaluating and mitigating the risks. While challenging, quantifying the global mass of plastics has previously been estimated for the OSL at 93,000 to 578,000 tonnes [7–9]. Spatial and temporal data gaps and variability in station-selection, sample-collection, and analysis make interpreting snapshots in time challenging and make establishing a trend even more difficult for the OSL [10]. Edelson et al. [11] suggested that the wide variability in reported inputs reveals an urgent need for improved monitoring frameworks to facilitate global governance. A few earlier trends offer a perspective of plastic accumulation in the oceans. Archived Continuous Plankton Recorder (CPR) samples show an increasing trend of microfibers since the 1960s [12] and an increasing trend of macroplastic entanglement since the late 1950s [13]. Day and Shaw [14] reported an increase of microplastics in the North Pacific between 1976 and 1985, and Wilcox et al. [15] observed an increasing trend in the western North Atlantic from 1986 to 2015, with a rate of increase paralleling global cumulative plastic production. Although these studies suggest long-term increases, they are only from northern oceans surrounded by the most industrialized countries. In contrast, other studies have found no evidence of a rise in plastic pollution over time [see references in [10]]. Here, we evaluate a global dataset with all available historical data to provide an estimate of the temporal tendencies of plastic concentrations in the global OSL. We also offer a historic overview of international policy measures to reduce plastic inputs; based on that evaluation we call for urgent and effective solutions. Materials and methods Data sets: Net-tow sample collection and analysis We compiled data on OSL plastic abundance and distribution from published literature and unpublished sources, totaling 11,777 stations used in this trend analysis (Fig 1; S1 Dataset and on GitHub https://github.com/wincowgerDEV/ocean_plastic_modeling). Data were aggregated primarily from peer-reviewed manuscripts and previously unpublishe (...truncated)