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.There is a similar confluence of plastics in the Atlantic as well.The debris ends up concentrated by circular, clockwise ocean currents within an oblong-shaped "convergence zone" hundreds of miles across from end to end near the Hawaiian Islands, about midway between Japan and the West Coast of the United States.