Not long ago it was plastic bags that where choking the inland waterways. I get the impression things have changed for the better, with noticeably less shredded bags around now. However I was walking along the lower reaches of the Tarwin river, looking for erosion\flood damage associated with kings tides. There in the flood debris I was very surprised to find how many plastic bottles have taken up residence (maybe it because they float, glass ones would sink). Seams the littering habit is still alive!