The Pacific Ocean's Garbage Patch needs more study
I keep reading about the Great Pacific Garbage Patch, that floating island of trash between California and Hawaii. Can we ever clean it up? And should we even bother?
The Lantern always thought the Garbage Patch was a huge, waterborne landfill -- sort of like a massive hair clog in a big drain. In reality, it's not so much an island of trash as a thin, soupy area of litter, mostly in the form of tiny flecks of plastic, studded here and there with old fishing gear and children's toys. Even if you were to sail right through the Patch, the water probably wouldn't look too remarkable, unless you scooped some up and looked at it closely. So cleaning this part of the ocean isn't as simple as you might imagine.
Because the trash is so dispersed, it's not like we can just steer a big ship out to sea and pick up the Garbage Patch. Collecting all those small fragments of plastic would be extremely expensive. Plus, thanks to a variety of factors -- from winter storms to El Niño -- the Garbage Patch moves, making it hard to target effectively. Finally, in gathering up those little scraps, you also run the risk of catching -- and killing -- any marine animals living amid the debris, many of which are the same size as the plastic bits.
For all these reasons, most organizations stress that the best way to keep oceans clean is to prevent garbage from getting there in the first place. The Lantern does know of one group that's actively testing methods for removing trash from the open seas: the San Francisco- and Hong Kong-based Project Kaisei. In the expeditions it is planning for 2010, Project Kaisei will focus on picking out big, derelict fishing nets, which can snare marine life in a process known as "ghostfishing." It's also planning to use modified purse seines -- large nets used by commercial fishing operations -- to collect the medium-sized pieces of garbage floating near the surface of the water. Finally, the project will continue to experiment with methods of gathering the smaller bits of debris.
Kaisei -- which receives some of its funding from a recycling trade organization -- is also looking for ways to squeeze value from the trash it collects. Currently, the group is focusing on methods that use pyrolysis -- in which heat is used to break down materials in the absence of oxygen -- to transform the collected waste into fuel. Some experts, however, are skeptical that this particular solution will make economic sense.
Meanwhile, we ought to know a lot more about the Garbage Patch before making a decision as to whether large-scale cleanup operations are viable or even warranted. There are still a lot of basic questions that remain unanswered. For example, no one has accurately estimated how much garbage enters the ocean each year. And despite the oft-repeated claim that the Great Pacific Garbage Patch is "twice the size of Texas," we don't really know the exact size of the Patch or how much garbage it contains.
Nor do we fully understand the precise impact of ocean trash. It's possible that, when all is said and done, we'll decide it's better to leave the Patch alone, rather than bringing all those bits and pieces back on land and dealing with a brand-new disposal headache. (Particularly when you consider all the emissions associated with fueling collection vessels.) Scientists do know that the marine debris can entangle or otherwise harm sea life: For example, animals may eat the garbage, which can not only lacerate their throats and stomachs but can also make them feel so full that they stop eating actual food. But it's hard to say with certainty exactly how many animals are killed this way. Some of the garbage patches in the Pacific have more teeming ecosystems than others , whereas the larger Garbage Patch itself (the area between California and Hawaii) is a relative dead zone, biologically. However, no matter where debris resides, it can pose a threat to wide-foraging seabirds such as the albatross. And, because garbage patches move, they can also sweep trash onto land, endangering shore animals such as seals.
There are even more questions about the risks posed by those tiny bits of plastic. It's well-established that plastic can absorb certain toxic pollutants such as PCBs and DDT, and that those pollutants -- if absorbed into an animal's fat tissues -- can work their way up the food chain. But according to Miriam Goldstein, who served as principal investigator on a recent expedition to the Garbage Patch, we can't yet draw any firm conclusions about the plastic's effects on human health. For example, while we do know that some fish species are eating these specks of plastic, we don't know whether they're doing so in numbers. We also don't know whether ingesting bits of polluted plastic is enough to transfer those toxins from the plastic into the fish's fatty tissues. (For that matter, there's already plenty of PCBs and DDT in the water itself, so even if we could remove all the plastic from the ocean, we wouldn't necessarily be fixing the toxic fish problem.)
None of this is to say that plastic in the oceans shouldn't be an area of concern. But unless the flow of garbage is stanched at the source, cleanup can only ever be a temporary solution.