Update Below
“The Great Pacific Garbage Patch is a heap of debris floating in the Pacific that’s twice the size of Texas, according to marine biologists. It is 80 percent plastics and weighs some 3.5 million tons, floating where few people ever travel, in a no-man’s land between San Francisco and Hawaii.”
The problem has been growing for years, in the Pacific most notably but in other oceans and bays as well.
PlasticDebris.org , Algalita Marine Research and GreenPeace are good resources.
The SF Chronicle covers the Great Pacific Garbage Patch on Tuesday 30th, including a few remarks from National Ocean and Atmospheric Administration (NOAA) about the possible clean up.