Tuesday, February 05, 2008

The Pacific trash vortex

The Independent today has a piece on the Pacific trash vortex, a vast area of the North Pacific which (thanks to a current system called the North Pacific gyre) has become a floating trash dump. But not just any trash - most stuff that ends up in the oceans biodegrades or sinks long before it makes its way to the gyre. Instead, this area is full of our longest-lasting waste: plastic. An estimated 100 million tons of it, forming a soup that stretches from Hawaii to Japan. Here's a description of the trash vortex from a piece on the pastic ocean:

It began with a line of plastic bags ghosting the surface, followed by an ugly tangle of junk: nets and ropes and bottles, motor-oil jugs and cracked bath toys, a mangled tarp. Tires. A traffic cone. Moore could not believe his eyes. Out here in this desolate place, the water was a stew of plastic crap. It was as though someone had taken the pristine seascape of his youth and swapped it for a landfill.
The basic problem is that plastic is both light (or rather, dense) enough to float, and also essentially immortal. Nothing eats plastic. It's not broken down by the environment, except by physical processes which grind it into plastic dust ("biodegradable" plastic bags simply break down into smaller pieces of plastic). So, it just piles up. And unfortunately its piling up in the oceans. This isn't just ugly - it's also a threat to the marine food chain. Macroscopic plastic items such as bottletops and pens may be mistaken for food and eaten by fish and marine animals. As plastic is indigestible, this is - eventually - fatal (there's a picture of the results at the top of this article). Microscopic fragments are eaten by plankton, with the same result. But worse, plastics attract and concentrate complex organic pollutants like PCBs - meaning that our dumping of plastic in the oceans is slowly poisoning our food chain. According to The World Without Us, there has already been one study correlating ingested plastics with PCBs in the fat tissue of puffins. And there will likely be more as people start looking. In short, plastics and chemical polluants are a toxic combination, and we're slowly poisoning ourselves with them.

What can we do about this? Recycle, for one (though that's not particularly effective, as thanks to low melting temperatures you can't safely make new plastic bottles out of old ones). Reduce usage as well (plastic supermarket bags are convenient, I know. But they're also a long-lasting problem). But most of all, clean up after yourself. Don't let this shit get in the oceans.