great garbage patches http://ocean.si.edu/ocean-news/ocean-trash-plaguing-our-sea vast "garbage patches". great garbage patches Oceanic markers marine debris http://ocean.si.edu/ocean-news/ocean-trash-plaguing-our-sea http://ocean.si.edu/ocean-news/ocean-trash-plaguing-our-sea marine debris vast gyres of rotating plastic trash out in the oceans marine debris The Great Pacific Garbage Patch great garbage patches