Scientists have discovered something surprising in the Atlantic Ocean. Much of the plastic pollution may no longer be visible at all. Instead, it exists as nanoplastics, extremely small particles measured in billionths of a meter.
“This estimate indicates that there is more plastic in the form of nanoparticles floating in this region of the ocean than larger microplastics and macroplastics floating in the Atlantic Ocean and even oceans around the world,” said Helge Niemann, a NIOZ researcher and professor of geochemistry at Utrecht University. In mid-June, he received a €3.5 million grant to further investigate nanoplastics and what might ultimately happen.
Tiny plastic particles discovered during ocean expedition
To collect the data, Sophie ten Hietobrink, a master’s student from Utrecht, spent four weeks aboard the research vessel RV Pelagia. The ship traveled from the Azores to the European continental shelf, collecting water samples at 12 different locations.
Each sample was carefully filtered to remove anything larger than 1 micrometer. What remained contained the smallest particles. “By drying and heating the remaining material, we were able to measure the characteristic molecules of different types of plastic using mass spectrometry in our laboratory in Utrecht,” explains Ten Hietbrink.
First actual measurement of marine nanoplastics
Previous studies have confirmed the presence of nanoplastics in seawater, but no one has been able to calculate how much is actually present. This study is the first time scientists have come up with meaningful estimates.
Niemann points out that this progress was made possible by combining expertise in ocean research and atmospheric science, including the contribution of Utrecht University scientist Dusan Materic.
27 million tons of invisible plastic
When the team took measurements across the North Atlantic, the results were surprising. They estimate that around 27 million tons of nanoplastics are floating in this region alone.
“It’s a shocking amount,” says Ten Hietbrink. This discovery may finally solve a long-standing mystery. Scientists have struggled to account for all the plastic ever produced. Much of that seemed to be missing. The study suggests that most of it has broken down into small particles and is currently floating in the ocean.
How do nanoplastics enter the ocean?
These microscopic plastics come from multiple sources. Large plastic pieces can become fragmented over time due to sunlight. Rivers also transport plastic particles from land to the ocean.
Another route comes from the atmosphere. Nanoplastics can travel through the air, fall into the ocean with rain, or settle directly on water surfaces through a process known as dry deposition.
Potential risks to ecosystems and human health
The widespread presence of nanoplastics raises serious concerns. Nieman points out that these particles are small enough to enter living organisms.
“We already know that nanoplastics can penetrate deep into our bodies. Nanoplastics are also present in brain tissue,” he says. Since it is now known to exist in the ocean, it is thought to travel throughout the food web, from microbes to fish and ultimately humans. The full effects on ecosystems and health are still unknown and require further research.
What scientists still don’t know
There are still important gaps in knowledge. The researchers did not detect certain common plastics such as polyethylene and polypropylene in the smallest particle range.
“It’s entirely possible that they were masked by other molecules in the study,” Nieman says. The research team also wants to see if similar levels of nanoplastics exist in other oceans. Early signs suggest this may be the case, but further research is needed.
Prevention may be the only solution
While this discovery fills a critical gap in our understanding of ocean pollution, it also presents a difficult reality. These particles are too small and spread too widely to be removed.
“The nanoplastics that are out there can never be cleaned up,” Niemann emphasizes. The findings highlight the urgency of preventing further plastic pollution before it develops into a more persistent and invisible problem.
