The contribution of commercial shipping to global marine plastic pollution
Topic 1: Operational leakages from cargoes of plastic pellets during maritime transportation
A distinct form of marine microplastic pollution is that of pre-production plastic pellets, also called nurdles. These lentil-sized plastic resin particles constitute the most common form of raw materials out of which plastic products are produced. Plastic pellets form the second largest source of microplastics in the marine environment and are found around the world. These very light and small particles disperse very quickly and are extremely difficult to clean up. The origin of plastic pellet pollution is often linked to land-based industrial sites and transportation. However, recent spills resulting from accidents with ships have highlighted the significance of maritime shipping as a source of plastic pellet pollution. In addition, plastic pellets may be released from ships into the ocean as a result of operational leakages during maritime transportation. Unsupported claims are that one out of every ten containerized consignments involves leakages of plastic pellets. Considering the large volumes of primary plastics that are internationally shipped via maritime transport, the contribution of these operational spills and leakages to global plastic pellet pollution may be considerable.
The aim of the current MSc project is to assess the scale and causes of plastic pellet pollution from maritime shipping containers as a result of operational leakages and spills. Thereto you will collect data from logistics providers and cargo owners, in the form of interviews and observations, as well as company data on previous incidents.
Topic 2: Dumping and littering of plastic waste from global maritime shipping
The International Convention for the Prevention of Pollution from Ships (MARPOL) includes regulations aimed at preventing and minimizing different forms of pollution from ships. Annex V of the MARPOL Convention prohibits the discharge of any type of plastics into the marine environment. However, various recent studies on remote shorelines have highlighted significant plastic pollution deriving from shipping activities, presumably as a result of deliberate dumping of plastic waste. Although most items in these studies were found to be produced in China, it remains unclear what kinds of shipping activities are responsible for this illegal form of pollution, which drivers lead to ship-based plastic dumping, and what the scale of the problem is.
The aim of the current MSc project is to explore the shipping activities, drivers and scale of the dumping of plastic waste into the sea by ships. Thereto, different approaches may be considered, including:
- Linking observations of presumed ship-based plastic pollution to geospatial data on shipping routes and activities in the form of AIS data;
- Crew interviews or questionnaires on experiences with shipboard garbage management on longer journeys, as well as sightings of illegal activities.
References:
- Benito-Kaesbach, A., Suárez-Moncada, J., Velastegui, A., Moreno-Mendoza, J., Vera-Zambrano, M., Avendaño, U., Ryan, P. G., & Sanz-Lázaro, C. (2024). Understanding the sources of marine litter in remote islands: The Galapagos islands as a case study. Environmental Pollution, 347, 123772. https://doi.org/10.1016/j.envpol.2024.123772.
- da Luz, T. M., de Matos, L. P., & Malafaia, G. (2025). Tracing Plastic Origins: Unveiling the Role of Ocean Currents and Commercial Shipping in Plastic Pollution on Coqueirinho Beach, Brazil. Earth Systems and Environment, 1–20. https://doi.org/10.1007/s41748-025-00600-7
- Galgani, F., & Rangel-Buitrago, N. (2024). White tides: The plastic nurdles problem. Journal of Hazardous Materials, 470, 134250. https://doi.org/10.1016/j.jhazmat.2024.134250
- GESAMP. (2023). Sea-based sources of marine litter.
- International Maritime Organization. Prevention of Pollution by Garbage from Ships.
- Ryan, P. G. (2023). Illegal dumping from ships is responsible for most drink bottle litter even far from shipping lanes. Marine Pollution Bulletin, 197, 115751. https://doi.org/10.1016/j.marpolbul.2023.115751.
- Ryan, P. G., Dilley, B. J., Ronconi, R. A., & Connan, M. (2019). Rapid increase in Asian bottles in the South Atlantic Ocean indicates major debris inputs from ships. Proceedings of the National Academy of Sciences, 116(42), 20892–20897. https://doi.org/10.1073/pnas.1909816116.
Contact: Maartje Folbert and Ansje Lohr