Hidden Pollution: Ship Paint May Add Over 11,000 Tons of Microplastics to Oceans Each Year

Ship paint identified as an underestimated source of microplastics

Plastic pollution — and microplastics in particular — remains a major threat to marine ecosystems. A recent study published in the October issue of the Journal of Hazardous Materials highlights a potentially large, underappreciated source: particles shed from marine paint applied to hulls and offshore structures.

The research team, from the Korea Institute of Ocean Science and Technology's Ecological Risk Research Department and the University of Science and Technology of Daejeon, used a combination of analytical approaches — including infrared spectroscopy, energy-dispersive X-ray spectroscopy (EDS) and density measurements — to examine how fragments of ship coatings may be overlooked or misclassified in standard microplastic surveys.

Key estimate: A 2021 study cited by the authors estimated that marine paint may contribute about 11,270 metric tons of microplastics to the oceans each year.

Commercial vessels, especially fishing boats, are already known contributors to ocean plastic — losses of nets and other gear can total up to a million tons annually. This new work draws attention to a less obvious source: durable marine coatings formulated to resist saltwater that can degrade over time and release microscopic particles.

The authors warn that ship paint-derived microplastics are "relatively under-investigated" compared with other plastic pollutants. That research gap likely means current estimates of marine microplastic loads and environmental impacts are incomplete.

Microplastics are now detected almost everywhere — in freshwater and seawater, soils, the food supply and the air. Growing evidence links microplastic exposure to harms in wildlife and potential health risks in humans, including inflammation, vascular effects and other concerns under active study.

What should happen next?

The researchers call for targeted studies that better characterize paint-derived particles, refine detection methods and quantify their transport and ecological effects. They also urge that policymakers and industry incorporate paint-derived particles into marine pollution inventories and mitigation plans.

What individuals can do

While systemic solutions are needed, individuals can reduce direct exposure and prevent further pollution by using less disposable plastic, choosing plastic-free alternatives for common items, supporting improved shipping and boat-maintenance practices, and participating in local river or beach cleanups to intercept debris before it degrades into microplastics.

Bottom line: Ship coatings are a plausible and likely significant source of marine microplastics that has received relatively little attention. Better detection, research and policy action are needed to fully understand and address this hidden form of ocean pollution.