Fifty years ago, most flotsam was biodegradable. Now it is 91% plastic, and practically indestructible. In 2006, the United Nations Environment Programme (UNEP) estimated that there are now 46,000 pieces of floating plastic in every square mile of ocean. Around 20% of it is rubbish from ships and harbours – buoys, fishing nets, that sort of thing but the rest is carrier bags, bottles, flip flops, children’s toys, tyres, yogurt pots: in short the detritus of modern consumer societies. Last year, rescuers searching for the wreckage of Air France flight 447, which disappeared over the South Atlantic, were astonished to find that instead of pieces of wreckage, their instruments were detecting vast amounts of rubbish.
How does so much plastic get into the sea? If it’s not dumped there directly, plastic rubbish is blown out of littered streets and landfills and conveyed by rivers and drains to the sea. It’s also washed off beaches. Once in the water, around 70% sinks to the ocean floor, while the remainder floats, usually within 20 metres of the surface. Out to sea, the rubbish is drawn into huge circular currents known as “gyres”, and accumulates in their centres. Huge pools of plastic are building up in each of the world’s five major gyres (two in the Atlantic, two in the Pacific, one in the Indian Ocean), but the greatest known concentration is in the North Pacific, where around six million tonnes have come together to form what campaigners call the Great Pacific Garbage Patch – a pool of rubbish twice the size of Texas!
How long has this been a problem? Scientists have worried about plastic rubbish in the oceans since the 1980s, but it wasn’t until 1997 that the scale of the problem was discovered by a Californian sailor called Charles Moore, who was on his way home from a race in Hawaii. He and his crew were motoring a catamaran across the top of the North Pacific Gyre, a route that boats normally avoid because of the lack of wind. As he made his way, Moore watched an unending procession of bottle caps, toothbrushes, Styrofoam cups, detergent bottles and plastic bags pass by. “It took us a week to get across, and there was always some plastic thing bobbing by,” he says.
Why on earth hadn’t it been noticed before? The idea of a raft or island of trash is misleading. The plastic is impossible to photograph from aircraft or satellites, and hard to see unless you’re in the middle of it. Even then, the larger pieces of plastic are only the beginning of the problem. They swim in a soup of tiny particles that are either plastic fragment’s worn down by friction and exposure to sunlight, or resin pellets – no more than 2mm across – known as “nurdles”, the micro-ingredients from which disposable plastics are made. Billions of tonnes of nurdles are shipped around the world every year, and a lot are spilled, lost and flushed down drains. Beachcombers call the nurdles “mermaids’ tears”.
What damage do they do? Biologists are only just beginning to work out the threat posed by nurdles and other flecks of plastic. Fish, birds and whales mistake them for tiny fish and zooplankton, and then find them impossible to digest. More worrying still is the fact they attract heavy metals and toxins in the ocean – industrial chemicals such as DDT and polychlorinated biphenyls (PCBs) that would otherwise have stayed out of the food chain. Once consumed by smaller animals, the pollutants become more concentrated as those animals are eaten in turn – eventually by humans. “You can buy certified organic farm produce, but no fishmonger on earth can sell you a certified organic wild-caught fish,” says Moore, who has now spent 13 years studying the problem.
Can’t we clean it all up? Moore is convinced it is too late. It would take an enormous amount of resources to remove six million tonnes of plastic from the North Pacific Gyre – and a total of around 100 million tonnes worldwide. What’s more, the mesh required to gather up the tiny plastic articles would be so fine that it would also entrap millions of fish, devastating the ocean’s ecology. Whatever happens, much of the plastic in the ocean will be there for centuries to come. Some predict that it will eventually form a layer in the geological record.
What can we do? The challenge is to rethink the way plastics are used and to stop them reaching the oceans in the first place. Support excellent researchers, camaigners and educational groups like those on the plastiki. Recycle where there are facilities to do so, unfortunately at present plastic continues to be an issue on Eigg as we have no recycling point yet but hopefully in the future we will. We trust in the meantime that everyone disposes of it in a responsible manner. By the progression of more locally produced foods the import of plastics will decrease and if everyone visiting Eigg and beyond continues to be aware and acts responsibly with their rubbish then pollution to our shores will be kept to a minimum and stay as beautiful as they are today!