Every year over 6.4 million tons of plastic debris end up in the sea. As the standard kinds of plastic are not degradable, they drift around the oceans for decades or indeed centuries and collect in enormous gyres of plastic debris. Today plastic is everywhere: on the open sea, on the sea floor and on beaches. There it not only disfigures the beauty of nature and leads to economic losses but also has alarming effects on nature, animals, and ultimately also on our health. The real cause of the plastic pollution of the seas is our thoughtless way of using plastics. Making use of plastic where it may not be necessary, littering, and the lack of waste management all lead to increasing amounts entering our waters. And, even where one would hardly suspect it, we contribute daily to marine pollution: by washing clothes made of synthetic fibers.