You may have heard of the "Great Pacific Garbage Patch," the swirling mess of plastic junk that's floating in a gyre in the pacific ocean. Well, as it turns out, there are five major gyres in our oceans and they all may be accumulating trash. The 5 Gyres Project is traveling to these major vortexes and documenting the pollution in each.
Here's a video model they've made of how our gyres are likely to grow over the next ten years (though I admit I'm not sure what the units on the x axis are).
There's much more at the 5 Gyres site.