Big rise in North Pacific plastic waste
Scientists from the Scripps Institution of Oceanography documented the big rise when they trawled the waters off California.
They were able to compare their plastic "catch" with previous data for the region.
The group reports its findings in the journal Biology Letters.
"We did not expect to find this," says Scripps researcher Miriam Goldstein.
"When you go out into the North Pacific, what you find can be highly variable. So, to find such a clear pattern and such a large increase was very surprising," she told BBC News.
All the plastic discarded into the ocean that does not sink will eventually break down.
Sunlight and the action of the waves will degrade and shred the material over time into pieces the size of a fingernail, or smaller.
An obvious concern is that this micro-material could be ingested by marine organisms...