The plastic didn’t disappear—it went invisible and spread everywhere.
Royal Netherlands Institute for Sea Research
Scientists have uncovered something surprising in the Atlantic Ocean. The majority of plastic pollution may no longer be visible at all. Instead, it exists as nanoplastics, particles so small they are measured in billionths of a meter.
"This estimate shows that there is more plastic in the
form of nanoparticles floating in this part of the ocean than there is in
larger micro- or macroplastics floating in the Atlantic or even all the world's
oceans!" said Helge Niemann, researcher at NIOZ and professor of
geochemistry at Utrecht University. In mid-June, he received a 3.5 million euro
grant to further investigate nanoplastics and what ultimately happens to them.
Ocean Expedition Reveals Tiny Plastic Particles
To gather data, Utrecht master's student Sophie ten
Hietbrink spent four weeks aboard the research vessel RV Pelagia. The ship
traveled from the Azores to the European continental shelf, where she collected
water samples at 12 different locations.
Each sample was carefully filtered to remove anything larger
than one 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 plastics in the Utrecht
laboratory, using mass spectrometry," Ten Hietbrink explains.
First Real Estimate of Ocean Nanoplastics
Previous studies had confirmed that nanoplastics existed in
ocean water, but no one had been able to calculate how much was actually there.
This research marks the first time scientists have produced a meaningful
estimate.
Niemann notes that this breakthrough was made possible by
combining ocean research with expertise from atmospheric science, including
contributions from Utrecht University scientist Dusân Materic.
27 Million Tons of Invisible Plastic
When the team scaled their measurements across the North
Atlantic, the results were striking. They estimate that about 27 million tons
of nanoplastics are floating in this region alone.
"A shocking amount," Ten Hietbrink says. The
finding may finally explain a long-standing mystery. Scientists have struggled
to account for all the plastic ever produced. Much of it appeared to be
missing. This study suggests that a large share has broken down into tiny
particles that are now suspended throughout the ocean.
How Nanoplastics Enter the Ocean
These microscopic plastics come from multiple sources.
Larger plastic debris can fragment over time due to sunlight. Rivers also carry
plastic particles from land into the sea.
Another pathway comes from the atmosphere. Nanoplastics can
travel through the air and fall into the ocean with rain or settle directly
onto the water's surface through a process known as dry deposition.
Potential Risks to Ecosystems and Human Health
The widespread presence of nanoplastics raises serious
concerns. Niemann points out that these particles are small enough to enter
living organisms.
"It is already known that nanoplastics can penetrate
deep into our bodies. They are even found in brain tissue," he says.
Because they are now known to be present throughout the ocean, they likely move
through entire food webs, from microorganisms to fish and ultimately to humans.
The full impact on ecosystems and health is still unclear and requires further
study.
What Scientists Still Don't Know
There are still important gaps in knowledge. Researchers did
not detect certain common plastics, such as polyethylene or polypropylene, in
the smallest particle range.
"It may well be that those were masked by other
molecules in the study," Niemann says. The team also wants to determine
whether similar levels of nanoplastics exist in other oceans. Early indications
suggest this could be the case, but more research is needed.
Prevention May Be the Only Solution
While this discovery fills a critical gap in understanding
ocean pollution, it also presents a difficult reality. These particles are too
small and too widespread to remove.
"The nanoplastics that are there can never be cleaned
up," Niemann emphasizes. The findings highlight the urgency of preventing
further plastic pollution before it breaks down into an even more persistent
and invisible problem.
Journal Reference:
- Sophie
ten Hietbrink, Dušan Materić, Rupert Holzinger, Sjoerd Groeskamp, Helge
Niemann. Nanoplastic concentrations across the North Atlantic. Nature,
2025; 643 (8071): 412 DOI: 10.1038/s41586-025-09218-1
