Nikolai Maximenko is trying to answer the question - where does all the junk that goes into the ocean end up?. Trash gathers into "garbage patches" that are too diffuse to spot from a satellite. Scientists have encountered several areas where trash collects in the ocean, but nobody is sure where all of it is.
Maximenko, a senior researcher with the International Pacific Research Center, led a team that created a computer model based on ocean currents to map out where those patches will pop up a decade after trash first enters the oceans:



What’s in that trash? For decades, the International Coastal Cleanup has been keeping an eye on the junk that turns up on beaches. The biggest offender was cigarettes and cigarette filters, which made up 25% of the trash it tracked between 1989 and 2007.

Second place went to paper and plastic bags, which made up 9% of the mess, closely followed by beverage lids. Check out this report to find more data, including how ocean trash differs in different parts of the world.
PDF document: http://s3.documentcloud.org/document...-challenge.pdf