This is John Dalsen: Ocean's Plastic Pollution and The Effects on Earth's Inhabitants.

John Dalsen work as an environmental artist when he started collecting driftwood in Victoria on the southern Australian coastline, with the intension of making furniture.  After stumbling across the vast amounts of plastic debris that were washing up on the shoreline. He was compelled to collect them with the intension of recycling the found plastics but found inspiration by their strange beauty where he has been using them in his art. 


Humanity is at a critical point in time, with our planet currently existing in a fragile ecological state, with global warming hastening unheard of changes, all amplifying the fact that we need all the help we can get.
— john dahlsen —

Besides the thongs, Dahlsen has made a series of totems out of plastic soda bottles, buoys, foam, and driftwood. In another series, Dahlsen uses found plastic bags (now banned in certain cities such as San Francisco), and layers them to create seascapes that resemble sand-sculptures.