March 22 is World Water Day. Today's guest is one at the forefront of tackling the unseen problem of microfibers in our water. Microfibers are shed by clothing in the wash and are, by count, the single largest contributor to watershed plastic pollution in developed countries and account for a significant portion of plastic waste entering the ocean. Stiv Wilson, Campaigns Director for The Story of Stuff, championed the campaign to ban micro-beads and is now demanding that clothing companies take responsibility for microfiber pollution.