January 2023, Article in peer-reviewed journal
Marine Pollution Bulletin

Annalisa Delre, Maaike Goudriaan, Victor Hernando Morales, Annika Vaksmaa, Rachel Tintswalo Ndhlovu, Marianne Baas, Edwin Keijzer, Tim de Groot, Emna Zeghal, Matthias Egger, Thomas Rockmann and Helge Niemann

  • Publication type: Article in peer-reviewed journal
  • Publication journal: Science Direct
  • Collaborators: NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology & Biogeochemistry (NL), University of Vigo, Biological Oceanography Group (ES), The Ocean Cleanup (NL), Egger Research and Consulting (CH), Utrecht University, Faculty of Science, Institute for Marine and Atmospheric Research (NL), Utrecht University, Faculty of Geosciences, Department of Earth Sciences (NL), University of Tromsø, CAGE - Centre for Arctic Gas Hydrate, Environment and Climate (NO)
  • DOI: 10.1016/j.marpolbul.2022.114544
  • Publication date: December 26, 2022


Ocean plastic pollution is a problem of increasing magnitude; yet, the amount of plastic at the sea surface is much lower than expected. Solar ultraviolet (UV) radiation can induce photodegradation, but its importance in determining the longevity of foating plastic remains unconstrained. Here, we measured photodegradation rates of different plastic types slightly larger than microplastics (virgin polymers and foating plastic debris) under simulated marine conditions. UV irradiation caused all plastic types to leach dissolved organic carbon, and to a lesser degree carbon dioxide, carbon monoxide, methane, and other hydrocarbon gases. The release of photodegradation products translates to degradation rates of 1.7–2.3 % yr−1 of the tested plastic particles normalized to conditions as found in the subtropical surface ocean. Modelling the accumulation of foating plastic debris, our results show that solar UV radiation could already have degraded 7 to 22 % of all foating plastic that has ever been released to the sea.

  • Microplastic, Photodegradation, UV light