To count the microplastics in the ocean, most scientists have turned to mesh nets to collect samples. But new research reveals that those nets might allow the tiniest plastic to escape, meaning there could be a million times more microplastics in the ocean than previously estimated.
Most studies looking at plastic in the ocean only captured pieces as small as 333 micrometers, according to the press release. The new research, led by biological oceanographer Jennifer Brandon along with researchers from Scripps Institution of Oceanography at the University of California San Diego, looked at plastic as small as 10 micrometers — tinier than the width of a human hair. Despite their tiny size, the new finding still has major consequences on the volume of plastics in the ocean. "The quantity is one million times more numerically, but when you multiply the quantity times volume, the volume of the larger pieces is still much higher," Brandon told Gizmodo.
To capture such small plastics, researchers analyzed 100 salps — filter-feeding invertebrates that live in the top 6,500 feet of the ocean — collected between 2009 and 2017 in the North Pacific. They found that 100 percent contained mini-microplastics, which was shocking to Brandon.
"I definitely thought some of them would be clean because they have a relatively quick gut clearance time," she said in the press release.
This is alarming, Brandon says, because the plastic will continue to break down into smaller pieces, but won't go back into the ecosystem. When species begin to ingest the plastic, it could work its way up the food chain, potentially becoming small enough to enter the human bloodstream — a concern considering the effects of plastic on health are relatively unknown.