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An inshore–offshore sorting system revealed from global classification of ocean litter


The surge of research on marine litter is generating important information on its inputs, distribution and impacts, but data on the nature and origin of the litter remain scattered. Here, we harmonize worldwide litter-type inventories across seven major aquatic environments and find that a set of plastic items from take-out food and beverages largely dominates global litter, followed by those resulting from fishing activities. Compositional differences between environments point to a trend for litter to be trapped in nearshore areas so that land-sourced plastic is released to the open ocean, predominantly as small plastic fragments. The world differences in the composition of the nearshore litter sink reflected socioeconomic drivers, with a reduced relative weight of single-use items in high-income countries. Overall, this study helps inform urgently needed actions to manage the production, use and fate of the most polluting human-made items on our planet, but the challenge remains substantial.

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Fig. 1: Material, plastic type and probable origin of the litter found in the seven major aquatic environments at a global scale.
Fig. 2: Top ten litter items in aquatic environments.
Fig. 3: Samples collected with surface-trawling macro-nets from offshore and nearshore surface waters.
Fig. 4: Conceptual model of the most likely predominant flows of the top litter items in the ocean.
Fig. 5: Macro-litter densities (items m−2) in ocean surface waters, shorelines, shallow (<50 m depth) and deep (>50 m depth) nearshore seafloor, and deep seafloor (>100 m depth).
Fig. 6: Top ten litter items in the nearshore seafloor of the seven large world socioeconomic regions.

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Data availability

Supplementary text and additional figures and tables can be found in the supplementary material. The data that support the findings of this study, as well as a tool (Excel macro) to automatically convert any litter category list into the joint master list (JML) used here, are available at and from the corresponding authors upon request.


  1. Galgani, F., Hanke, G. & Maes, T. in Marine Anthropogenic Litter (eds Bergmann, M. et al.) 29–56 (Springer, 2015).

  2. Crippa, M. et al. A Circular Economy for Plastics: Insights from Research and Innovation to Inform Policy and Funding Decisions (European Commission, 2019).

  3. Weideman, E. A., Perold, V., Arnold, G. & Ryan, P. G. Quantifying changes in litter loads in urban stormwater run-off from Cape Town, South Africa, over the last two decades. Sci. Total Environ. 724, 138310 (2020).

    Article  CAS  Google Scholar 

  4. Jambeck, J. R. et al. Plastic waste inputs from land into the ocean. Science 347, 768–771 (2015).

    Article  CAS  Google Scholar 

  5. Cózar, A. et al. Plastic debris in the open ocean. Proc. Natl Acad. Sci. USA111, 10239–10244 (2014).

    Article  Google Scholar 

  6. Eriksen, M. et al. Plastic pollution in the world’s oceans: more than 5 trillion plastic pieces weighing over 250,000 tons afloat at sea. PLoS ONE 9, e111913 (2014).

    Article  Google Scholar 

  7. van Sebille, E. et al. A global inventory of small floating plastic debris. Environ. Res. Lett. 10, 124006 (2015).

    Article  Google Scholar 

  8. Lebreton, L. et al. Evidence that the Great Pacific Garbage Patch is rapidly accumulating plastic. Sci. Rep. 8, 4666 (2018).

    Article  CAS  Google Scholar 

  9. Ocean Conservation 2011 Annual Report (International Ocean Conservancy, 2011).

  10. Marine LitterWatch (European Environment Agency, accessed 20 April 2018);

  11. Canals, M. et al. The quest for seafloor macrolitter: a critical review of background knowledge, current methods and future prospects. Environ. Res. Lett. 16, 023001 (2021).

    Google Scholar 

  12. Ó Briain, O., Marques Mendes, A. R., McCarron, S., Healy, M. G. & Morrison, L. The role of wet wipes and sanitary towels as a source of white microplastic fibres in the marine environment. Water Res. 182, 116021 (2020).

  13. Richardson, K., Hardesty, B. D. & Wilcox, C. Estimates of fishing gear loss rates at a global scale: a literature review and meta-analysis. Fish Fish. 20, 1218–1231 (2019).

    Article  Google Scholar 

  14. Morritt, D., Stefanoudis, P. V., Pearce, D., Crimmen, O. A. & Clark, P. F. Plastic in the Thames: a river runs through it. Mar. Pollut. Bull. 78, 196–200 (2014).

    Article  CAS  Google Scholar 

  15. de Stephanis, R., Giménez, J., Carpinelli, E., Gutierrez-Exposito, C. & Cañadas, A. As main meal for sperm whales: plastics debris. Mar. Pollut. Bull. 69, 206–214 (2013).

    Article  Google Scholar 

  16. Gilardi, K. et al. Sea-Based Sources of Marine Litter—A Review of Current Knowledge and Assessment of Data Gaps (FAO, 2020).

  17. Ryan, P. G., Dilley, B. J., Ronconi, R. A. & Connan, M. Rapid increase in Asian bottles in the South Atlantic Ocean indicates major debris inputs from ships. Proc. Natl Acad. Sci. USA 116, 20892–20897 (2019).

    Article  CAS  Google Scholar 

  18. Roman, L. et al. A global assessment of the relationship between anthropogenic debris on land and the seafloor. Environ. Pollut. 264, 114663 (2020).

    Article  CAS  Google Scholar 

  19. Plastics—The Facts 2017 (Plastic Europe, 2017).

  20. Andrady, A. L. in Marine Anthropogenic Litter (eds Bergmann, M. et al.) 57–72 (Springer, 2015).

  21. Ryan, P. G. Does size and buoyancy affect the long-distance transport of floating debris? Environ. Res. Lett. 10, 84019 (2015).

    Article  Google Scholar 

  22. Lebreton, L., Egger, M. & Slat, B. A global mass budget for positively buoyant macroplastic debris in the ocean. Sci. Rep. 9, 12922 (2019).

    Article  Google Scholar 

  23. Maximenko, N., Hafner, J. & Niiler, P. Pathways of marine debris derived from trajectories of Lagrangian drifters. Mar. Pollut. Bull. 65, 51–62 (2012).

    Article  CAS  Google Scholar 

  24. Lebreton, L.-M., Greer, S. D. & Borrero, J. C. Numerical modelling of floating debris in the world’s oceans. Mar. Pollut. Bull. 64, 653–661 (2012).

    Article  CAS  Google Scholar 

  25. Van Sebille, E., England, M. H. & Froyland, G. Origin, dynamics and evolution of ocean garbage patches from observed surface drifters. Environ. Res. Lett. 7, 44040 (2012).

    Article  Google Scholar 

  26. Yoon, J.-H., Kawano, S. & Igawa, S. Modeling of marine litter drift and beaching in the Japan Sea. Mar. Pollut. Bull. 60, 448–463 (2010).

    Article  CAS  Google Scholar 

  27. Isobe, A. et al. Selective transport of microplastics and mesoplastics by drifting in coastal waters. Mar. Pollut. Bull. 89, 324–330 (2014).

    Article  CAS  Google Scholar 

  28. Kukulka, T., Proskurowski, G., Morét-Ferguson, S., Meyer, D. W. & Law, K. L. The effect of wind mixing on the vertical distribution of buoyant plastic debris. Geophys. Res. Lett. 39, L07601 (2012).

    Article  Google Scholar 

  29. Reisser, J. et al. The vertical distribution of buoyant plastics at sea: an observational study in the North Atlantic Gyre. Biogeosciences 12, 1249–1256 (2015).

    Article  Google Scholar 

  30. Polasek, L. et al. Marine debris in five national parks in Alaska. Mar. Pollut. Bull. 117, 371–379 (2017).

    Article  CAS  Google Scholar 

  31. Ko, C.-Y. et al. Monitoring multi-year macro ocean litter dynamics and backward-tracking simulation of litter origins on a remote island in the South China Sea. Environ. Res. Lett. 13, 44021 (2018).

    Article  Google Scholar 

  32. Maximenko, N., Hafner, J., Kamachi, M. & MacFadyen, A. Numerical simulations of debris drift from the Great Japan Tsunami of 2011 and their verification with observational reports. Mar. Pollut. Bull. 132, 5–25 (2018).

    Article  CAS  Google Scholar 

  33. Egger, M. et al. A spatially variable scarcity of floating microplastics in the eastern North Pacific Ocean. Environ. Res. Lett. 15, 114056 (2020).

    Article  CAS  Google Scholar 

  34. Olivelli, A., Hardesty, B. D. & Wilcox, C. Coastal margins and backshores represent a major sink for marine debris: insights from a continental-scale analysis. Environ. Res. Lett. 15, 074037 (2020).

    Article  Google Scholar 

  35. Pedrotti, M. L. et al. Changes in the floating plastic pollution of the Mediterranean Sea in relation to the distance to land. PLoS ONE 11, e0161581 (2016).

    Article  Google Scholar 

  36. Efimova, I., Bagaeva, M., Bagaev, A., Kileso, A. & Chubarenko, I. P. Secondary microplastics generation in the sea swash zone with coarse bottom sediments: Laboratory experiments. Front. Mar. Sci. 5, 313 (2018).

  37. Lavers, J. L. & Bond, A. L. Exceptional and rapid accumulation of anthropogenic debris on one of the world’s most remote and pristine islands. Proc. Natl Acad. Sci. USA 114, 6052–6055 (2017).

    Article  CAS  Google Scholar 

  38. Pham, C. K. et al. Marine litter distribution and density in European seas, from the shelves to deep basins. PLoS ONE 9, e95839 (2014).

    Article  Google Scholar 

  39. Tubau, X. et al. Marine litter on the floor of deep submarine canyons of the northwestern Mediterranean Sea: the role of hydrodynamic processes. Prog. Oceanogr. 134, 379–403 (2015).

    Article  Google Scholar 

  40. van Sebille, E. et al. The physical oceanography of the transport of floating marine debris. Environ. Res. Lett. 15, 023003 (2020).

    Article  Google Scholar 

  41. Barboza, L. G. A. et al. in World Seas: An Environmental Evaluation Vol. 3 (ed. Sheppard, C.) Ch 17 (Elsevier, 2018).

  42. Directive (Eu) 2019/904 of the European Parliament and of the Council of 5 June 2019 on the Reduction of the Impact of Certain Plastic Products on the Environment (European Council, 2019).

  43. The Environmental Protection (Plastic Straws, Cotton Buds and Stirrers) (England) Regulations 2020 UK Draft Legislation (UK DEFRA, 2020).

  44. Leal Filho, W. et al. An overview of the problems posed by plastic products and the role of extended producer responsibility in Europe. J. Clean. Prod. 214, 550–558 (2019).

    Article  Google Scholar 

  45. Hogg, D. et al. Options and Feasibility of a European Refund System for Metal Beverage Cans Final Report (Publications Office of the European Union, 2011).

  46. Guidelines for the Implementation of MARPOL Annex V (International Maritime Organization, 2017);

  47. Ryan, P. G., Pichegru, L., Perold, V. & Moloney, C. L. Monitoring marine plastics—will we know if we are making a difference? S. Afr. J. Sci. 116, 7678 (2020).

    CAS  Google Scholar 

  48. Data Bank (World Bank, accessed 20 April 2018);

  49. Consoli, P. et al. Characterization of seafloor litter on Mediterranean shallow coastal waters: evidence from Dive Against Debris®, a citizen science monitoring approach. Mar. Pollut. Bull. 150, 110763 (2020).

    Article  CAS  Google Scholar 

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This work has been financed by the Spanish Ministry of Science, Innovation and Universities, CTM2016-77106-R, AEI/FEDER/UE through the MIDaS project. The 2014-2020 ERDF Operational Programme and the Regional Government of Andalusia (ref. FEDER-UCA18-107828, PLAn project) supported C.M.-C., and the BBVA Foundation (PLASTREND project) supported D.G.-F.. The European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no_715386) supported E.v.S. This study is the outcome of the huge labour of many dedicated volunteers and researchers who have cleaned and recorded litter all around the world together with ECOPUERTOS, Marine Litter Watch, Ocean Conservancy, Project Aware, The Great Canadian Shoreline Cleanup, The Ocean Cleanup and RIMMEL. The icons displayed in the figures were originally provided by Surfrider Foundation Europe. Thanks to A. L. Fanning for valuable comments on the document.

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Authors and Affiliations



C.M.-C. and A.C. conceived and drafted the present study; they contributed equally to the work. A.C., D.G.-F., H.P.-R., J.I.G.-G., E. Montero, G.M.A., G.H., O.C.B., N.M., L.L., T.v.E. and C.I. participated in the design and coordination of the field surveys. C.M.-C., J.V., A.C., E. Martí and D.G.-F. analysed the data. All authors read and commented on the manuscript.

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Correspondence to Carmen Morales-Caselles or Andrés Cózar.

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The authors declare no competing interests.

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Peer review information Nature Sustainability thanks Lauren Roman and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Methods, Table 1, Figs. 1–8 and references.

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Morales-Caselles, C., Viejo, J., Martí, E. et al. An inshore–offshore sorting system revealed from global classification of ocean litter. Nat Sustain 4, 484–493 (2021).

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