Marine scientists from California have ventured into the middle of the North Pacific for a study of plastic debris accumulating across hundreds of kilometres of open sea which has been dubbed the Great Pacific Garbage Patch.
A research vessel carrying a team of about 30 researchers, technicians and crew members is 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.
The focus of the study will be on plankton, other micro-organisms, small fish and birds.
The deputy director of research at Scripps, Bob Knox, says the concern is what kind of impact the plastic is having on the small organisms at the low end of the ocean food chain.