An overwhelming amount of plastics hauled from the patch trace back to fishing industries in Japan, China, South Korea, and the US.

For decades, our oceans have been filling up with trash. The North Pacific Garbage Patch, also called the Great Pacific Garbage Patch, has accumulated approximately 80,000 tons of plastic waste—and that estimate continues to climb.

Most of the litter in the ocean is delivered by rivers that carry waste and human pollution from land to sea. But the origins of floating debris in offshore patches haven’t been fully understood.

Between 75 to 86 percent of the plastics floating in the Great Pacific Garbage Patch come from offshore fishing and aquaculture activities, according to an analysis of the trash collected by nonprofit project the Ocean Cleanup.

Major industrialized fishing nations, including Japan, China, South Korea, the US, Taiwan, and Canada, were the main contributors of the fishing waste.

“These findings highlight the contribution of industrial fishing nations to this global issue,” says Laurent Lebreton, lead study author and head of research at the Ocean Cleanup.

The Great Pacific Garbage Patch, a region twice the size of Texas between the West Coast of North America and Japan, is one of several vortexes in the ocean where waste accumulates. Created by spinning currents, or gyres, each vortex churns and crushes plastics into tiny undegradable bits that are tricky for cleanup efforts to scoop up.

Plankton nets are used to collect these microplastics, often no more than 5 millimeters in size, says Lebreton. “But it is currently impossible to retrace an accurate origin for this pollution,” he says.

The team’s approach uses vessels that pull a long U-shaped barrier through the water, guiding the larger plastics into the catch system. “This provided us with a unique opportunity to study larger plastic objects that were not the focus of previous research efforts,” says Lebreton.