The December 7, 2007, This American Life episode #253, titled in The Middle of Nowhere, has a brief, sobering article about the largest rubbish piles in the world, which are in fact in the middle of the ocean.
http://www.thisamericanlife.org/Radio_Episode.aspx?sched=1057
You can learn more about Captain Moore and his research.
http://www.algalita.org/
