Billions of Ocean Nanoplastics Can Get Lodged in Sea Creatures in Only a Few Hours

A new study looked at a more realistic concentration level of tiny plastics like the kind we see in the ocean, and found the pieces quickly get lodged in animals’ tissue.
Tiny pieces of plastic
Image: Oregon State University/Flickr

In less than the span of a workday, nanoplastics in water can make their way into organisms, a new study shows. In just six hours, scallops placed in water spiked with plastic nanoparticles had billions of particles throughout their major organs, a study published in Environmental Science and Technology showed.

Previous studies have shown how invasive different nanoparticles can be to marine organisms, but for this experiment, researchers at the University of Plymouth in the UK wanted to investigate the impact of plastic concentrations actually found in the ocean. First, they created plastic nanoparticles in the lab, then they created water environments with the same concentration of plastic as the ocean and introduced some scallops into the environment.

Within six hours, billions of particles that were 250nm (that’s about 0.00025 mm) were found throughout the scallops’ intestines, while even tinier pieces measuring 20nm were lodged in the mollusks’ kidneys and gills. The scallops were then placed back in clean water, but it took weeks—up to six weeks—of living in the clean environment for the scallops to expel all of the nanoparticles.

“We only exposed the scallops to nanoparticles for a few hours and, despite them being transferred to clean conditions, traces were still present several weeks later,” Professor Richard Thompson, a coauthor on the study and a researcher at Plymouth, said in a press release. “Understanding the dynamics of nanoparticle uptake and release, as well as their distribution in body tissues, is essential if we are to understand any potential effects on organisms.”

The amount of plastic pollution in the ocean, particularly tiny bits of ground up plastic called microplastics, is staggering. Recent studies have shown rivers flowing into the ocean with as much as 500,000 microplastic particles per square metre. A common estimate that there are five trillion plastic particles in the ocean is now considered wildly underestimated. But despite the concerning amount of plastic pollution flooding our oceans every day, we still don’t completely understand what impact the plastic has on ocean life.

We know these tiny particles make their way up the food chain and are eventually consumed by us humans, through the fish we eat and even the salt we sprinkle on our meals, but we don’t fully understand what impact that has on us. But as this recent study shows, at least in scallops, it doesn’t take very long for a small amount of plastic to do a considerable amount of damage—and it takes a hell of a lot longer to undo it.