US scientists study huge plastic patch in Pacific

A research vessel carrying a team of about 30 researchers, technicians and crew members embarked on Sunday on a three-week voyage from the Scripps Institution of Oceanography, based at the University of California at San Diego.

The expedition will study how much debris -- mostly tiny plastic fragments -- is collecting in an expanse of sea known as the North Pacific Ocean Gyre, how that material is distributed and how it affects marine life.

The debris ends up concentrated by circular, clockwise ocean currents within an oblong-shaped "convergence zone" hundreds of miles (km) across from end to end near the Hawaiian Islands, about midway between Japan and the West Coast of the United States.

The focus of the study will be on plankton, other microorganisms, small fish and birds.

"The concern is what kind of impact those plastic bits are having on the small critters on the low end of the ocean food chain," Bob Knox, deputy director of research at Scripps, said on Monday after the ship had spent its first full day at sea.

The 170-foot (52 meters) vessel New Horizon is equipped with a laboratory for on-board research, but scientists also will bring back samples for further study.