In the visualization, you can investigate data to see how much plastic is currently floating in the ocean. The data was compiled from 24 expeditions over the course of 2007 to 2013. The estimated amount: 268,000 tonnes....or 590,838,863 pounds. Considering how light plastic is, that's a lot of plastic. On the map, each dot represents 20 kilograms of plastic (44 pounds). In plotting the map of estimated marine debris, 13 million dots are here on the map... the result of 5 trillion plastic pieces in the world's oceans.
A wealth of information is available on this website by clicking the "Learn More" link in the bottom left hand corner of the interactive map. Be sure to check it out!