Apparently, plastic materials that landed in the sea do not always get washed up onto the shores of countries. Instead, they flow along with the currents in the sea and the ocean into a dead zone (somewhere in between Hawaii and California) where all the plastic trash gather. Currently, there is no country that cleans up this growing pool of trash as it does not fall in any country’s Economic Exclusive Zone, not even the closest country, USA. Any efforts to clean up this mess will require an international effort.
While reading, this reminds me of several blog posts (or here) that DK posted up on mass release of balloons. Chances are that the balloons or the remains of it will end up in this pile of trash, which is detrimental to marine ecology.