Diamonds are forever, they say. But plastic – while not as sparkly – lasts nearly as long. In fact, most plastics persist for hundreds to thousands of years without much change. This durability may be appealing if you want to leave clues for future archaeologists. But on a global sustainability level, plastic is one of the bad guys.
This resistance to natural biodegradation processes leads to an accumulation of plastics in landfills. Many items end up in the marine environment, where they drift, become entangled, and often litter beaches. Plastic bottles are a major contributor, followed by plastic bags, fishing line, and other plastic pieces.
The UK’s Marine Conservation Society held a massive survey of beach litter in 2007. Trash continues to increase from year to year, including plastics as well as cigarette butts, cotton buds (the plastic versions), and other items. Nearly 60% of all UK beach litter is some form of plastic. Surveys from Canada and other countries have shown similar results, even from the most remote locations.
Some plastics, such as polystyrene, can fragment into smaller and smaller pellets. They may become less noticeable, but they are still present. Filter-feeding organisms take in floating pieces. Tiny plankton may contain plastic, and consumers up the food chain may bioaccumulate much larger quantities. Larger plastics are found in marine mammals, large fishes, seabirds, and turtles, after being mistaken for jellyfish and other edible organisms – balloons are notorious for confusing animals. These indigestible pieces can lead to injury and even death, through digestive blockage, strangulation, or amputation.
Even visibly clean beaches can have significant levels of microscopic plastic fibres, with up to 10,000 fibres per litre of sand. These tiny fragments are everywhere, thanks to accidental spills, leakages, and effluent. Much of this material is intended for use in plastic manufacture, where small pellets – nerdles – are melted to create other products. As many as 100,000 pellets per metre were counted along the New Zealand coast – far from most sources. Less quantifiable are the even tinier plastic particles, from cosmetics and industrial processes, that pass through sanitation systems.
Much of the litter on beaches comes from beachgoers (35%). But simple measures could reduce the problem. Reusing plastic bags – or bringing fabric bags – as well as responsible garbage disposal would have a significant impact. Even more ambitious solutions to the plastic problem are needed, since the debris has so many different forms and routes into the ocean. Tougher legislation, improved public awareness, regular clean-up, and zero waste policies are key aspects of the proposed strategies.
