I’m not sure if this is the right place to post this, but I’ve just read an interesting article on the Beeb’s website about a young Dutch man who has an idea for how to gather the plastic bits that we know are floating in the oceans and scoop them up.
http://www.bbc.com/news/magazine-29631332
The diagram doesn’t load where I am, and some of the comment says that cleaning up rivers might be more important, and it’s not totally perfect, but interesting reading none the less.