The earth’s oceans contain complex currents, and in several places these form rotating systems. It’s a lot like the convection you might have learned about in school. Water is warmed at the equator and begins to move steadily north, taking the place of colder water. Once it gets too far north though, it loses steam, cools down and ends up being pushed back towards the equator by more northerly bound water. These circular currents are called gyres.
There are 5 main gyres in the world’s oceans
Oceanic currents are surprisingly strong, and in the not too distant past scientists began to discover that a century’s worth of plastic rubbish has been collecting in them. The scale of the problem is horrifying. The great pacific rubbish gyre, for example, is approximately the size of Texas and contains roughly 3.5 million tonnes of rubbish; old fishing nets, plastic bottles, crisp packets, ice cream tubs and wedges of polystyrene are among it’s dubious inhabitants.
Plastics like polystyrene will almost never be broken down in the seas as nothing natural has enzymes the correct shape or acids strong enough to disrupt their strong chemical bonds. Unfortunately what does happen quite readily in rough seas is mechanical degradation of the plastics. Over a few years in the water they can be broken down into really quite tiny pieces, so small that they can be ingested by most of the diverse life living in our oceans. Once inside the creatures, they basically stay there forever. As the animals ingest more and more plastics they become dehydrated and are eventually overcome.
Luckily sights like that shown in the picture above are extremely rare. Most of the plastic is the size of grains of rice, and since the sun bleaches most of the colour out of it, there is little tangible rubbish in most of the patch. It’s the small size of the waste which, scientists have started to realise, makes it so dangerous . It’s not just that the wildlife becomes dehydrated. Many toxic organic chemicals are not soluble in water, so usually don’t do too much harm to fish (relatively speaking). Conversely, they do ‘dissolve’ in plastics; especially in porous ones like polystyrene. This means the world’s gyres have been slowly turning into something of a pea soup – only here all the peas are extremely small and have been loaded with deadly poisons.
Polystyrenes are chemically very stable, and so don’t get degraded in the sea (or anywhere else for that matter).
A crate marked with South Korean characters floats in the mid pacific
Styrofoam (polystyrene) juxtaposed with crabs..
Despite suggestions that we should claim this new trash continent for humankind (I can just see the stars and stripes being plunged into a buoy) and start sending package holidayers there, no one has yet come up with a credible solution for dealing with it (ideas in the comment section please science fans).
There is a glimmer of good news though. This week the now legendary Barac Obama unveiled his new plan to begin streamlining America’s use of the oceans which come under American jurisdiction, an area 20% larger than the country itself . The report candidly doesn’t give away any new cash and doesn’t really deal with pollution as a specific issue. Rather the Whitehouse staff have created a new ‘National Ocean Council’ who will coordinate the efforts of various regional US authorities. This should mean that at least oil exploration missions and endangered species protection schemes, managed by separate authorities will no longer bump into each other and, overall, it should lead to less polluted seas in America’s exclusive economic zone. On the other hand the report has no mention of how to respond to the enigma of the garbage patch. I think that’s because no one has any idea how to, and since the mid pacific does not ‘belong’ to anyone, I wonder how long it will be before anyone tries to fix it?
1. I should mention that the photos on this post were taken from freelance journalist Lindsey Hoshaw’s blog.
2. See a report here.
See more harrowing photos of the garbage patch here.