Water, Sewage & Effluent September October 2018 | Page 24

Planet’s plastic plight Of all the pollution that could beset this planet, plastic is the one that has resonated with public consciousness — in a big way.  By Kim Kemp What starts off as a convenience in the shop, more often ends up as an inconvenience and a pollutant in the sea. T he world is increasingly focusing on sustainability of the planet, with countries getting on board to make a noticeable difference in cleaning up our act. Governments, businesses, and global citizens are already tackling the obscene amount of one-use, or useless, plastic waste we throw out every day, which eventually makes it way to bulging landfills, to sit there for infinitum, or to the sea, borne by wind and waterways. Everywhere you look, you can see plastic, whether it be that plastic cutlery set that arrived with your take away, the plastic pen you are making you shopping list with, or even the plastic handles you hold as you push your trolley through the endless aisles of plastic packaged groceries or the plastic bottle of water in your bag. We are inundated with the stuff. In this light, there is a worldwide movement to get rid of plastic shopping bags and replace them with paper or reusable cotton tote bags. South Africa climbed onto the anti- plastic bag bandwagon, making us all pay for the privilege of having one, or two, or more. When first implemented, there was a significant drop in plastic bag use; however, in a paper, Johane 22 Dikgang, Anthony Leiman, and Martine Visser from UTC found that over time, the inconvenience of a plastic bag charge is gaining acceptance and the public no longer bothers about the 50-cents-odd they have to pay per bag. It appears that the collective conscience no longer worries about where that bag may end up. The problem is, it’s all but indestructible once you no longer have use for it. Trash Travel’s Ocean Conservancy is a non-profit environmental advocacy group based in Washington, DC, United States. The organisation helps formulate  ocean  policy at the federal and state government levels based on peer-reviewed science. It estimates that plastic bags can take  20 years to decompose, plastic bottles up to 450 years, and fishing lines some 600 years; but in fact, no one really knows how long plastics will remain in the ocean. With exposure to UV rays and the ocean environment, plastic breaks down into smaller and smaller fragments, becoming mistaken for food/plankton and being ingested by sea fowl and other marine dwellers. “Humanity’s plastic footprint is probably more dangerous than its Water Sewage & Effluent September/October 2018 carbon footprint,” said Captain Charles Moore, who, in 1997, discovered the Great Pacific Garbage Patch. The Great Pacific Garbage Patch, the most notorious stretch of plastic debris, is located north-east of Hawaii, about 1  000 miles from Hawaii and California. A huge island of marine debris, it is trapped by one of the five major subtropical gyres (systems of ocean currents) that gathers and carries marine garbage into its vortex.  An organisation that partners with Moore’s Algalita Marine Research Foundation to study plastic pollution in the ocean, 5 Gyres, has sent expeditions across the North Pacific Gyre; the North and South Atlantic Gyres; and the Indian Ocean Gyre, and found plastic — though concentrations vary — in all of them. The Great Pacific Garbage Patch is estimated to be twice the size of the continental United States, but no one can accurately measure the trash gyres because they are vast, remote, and continually shifting with ocean conditions. While some plastic and marine debris comes from fishing gear, offshore oil and gas platforms, and ships, 80% of it  comes from the land through a variety of methods. It constitutes