Where does plastic in the ocean come from?: Using the end location to find the likelihood of a possible start location of plastic particles in the ocean

In the ocean resides a large amount of plastic. This has severe environmental consequences for the oceans. To be able to clean up all this plastic the location of the plastic is needed. A lot of times plastic is cleaned up at the source, but to clean up here this location needs to be known. However, what if the start location is not known and...