The United Nations Environmental Program recently estimated that "for every square mile of ocean" there are about "46,000 pieces of plastic."Many of us have seen the truly sobering videos and photos of the Pacific garbage patch, which is twice the size of Texas. To help us understand the thorny problem that is plastic pollution in our oceans, we're chatting with Mimi Ausland, a passionate activist and founder of Free the Ocean, an organization dedicated to getting plastics out of our oceans.&...