But what alarmed them most, they said Tuesday, was the nearly inconceivable amount of tiny, confettilike pieces of broken plastic. They took hundreds of water samples between the Farallon Islands near San Francisco and the notorious garbage patch 1,000 miles west of California, and every one had tiny bits of plastic floating in it. And the closer they sailed to the garbage patch, which some researchers have estimated to be twice the size of Texas, the more plastic pieces per gallon they found.

“Marine debris is the new man-made epidemic. It’s that serious,” said Andrea Neal, principal investigator on the Kaisei, a 151-foot research ship on the trip.

Neal, a Santa Barbara researcher who has a doctorate in molecular genetics and biochemistry, said crews on the three-week voyage discovered tiny jellyfish eating bits of the plastic debris. The jellyfish are, in turn, eaten by fish like salmon or tuna, which people eat.