Now an international team of researchers believe they may be closer to determining where Earth’s “missing plastics” end up, using an unprecedented global effort to track and draw down one of the most polluting materials ever invented. As images of plastic-clogged beaches and swirling gyres of detritus bobbing on the high seas are prompting governments and cities to curb their throwaway culture, a growing body of evidence suggests a deeper problem of plastic permeating all ocean depths.