|
Thursday, 14 August 2008 |
By Griff Lambert
Benicia, CA
Anyone who has visited an ocean beach anywhere in the world in the past two decades will be aware of the problem of drifting ocean-borne trash. What washes up on the beaches, however, is a tiny fraction of the floating plastic debris making its way around the globe, most of which gets trapped by the North Pacific Gyre. This zone of intersecting ocean currents, stretching from the US west coast to Japan, forms at its center a slowly clockwise-rotating vortex that has become the biggest garbage dump in the world. The floating layer of plastics found there, in an area estimated to be at least the size of the state of Texas and perhaps as large as 15 million square miles, poses an ecological threat which is only recently coming to be studied.
Plastics do not biodegrade in the ocean, but that doesn’t mean that they don’t break down. Over time sun and salt water cause the types of lightweight polymer plastics that like to float (plastic grocery bags, food wrappers, water bottles and other beverage containers, buckets and particularly monofilament fishing line) to become brittle and break into smaller pieces. As these pieces become small enough they are ingested by marine organisms from fishes and jellyfish to marine mammals and birds. The plastic that remains afloat also interferes with the sunlight that supports plankton production in the upper part of the water column beneath what has been called by oceanographic researcher Curtis Ebbesmeyer the “Eastern Garbage Patch.”
Captain Charles Moore, who first brought attention to the problem after sailing through it during the TransPac ocean race in the late 1990’s, estimates that only 20% of these wastes come from ships, which are allowed to dump trash at sea 200 miles off-shore. The rest, 80% of the plastic waste, comes from land sources. It is estimated that a plastic garbage bag washed into the ocean off California will make it to the Eastern Garbage Patch in five years. Captain Moore speculates that there is plastic afloat there dating as far back as the 1950’s, or the beginning of the plastics era.
Although studies of the problem have been under way since 2000, there are currently no proposals being put forward to deal with it. In fact, some don’t even look at the existence of the Great Pacific Garbage Patch, as it is also called, as a problem needing intervention. Since these types of plastics are not generally profitable to recycle, no enterprise has come along that sees the Garbage Patch as an untapped resource, so the answer to the question, “What to do?” is, so far, “Nothing.” Like most of the environmental threats looming today, this one will probably not rise to attention until it begins to have an impact on our convenience.
The views expressed are those of the author and do not necessarily represent policies and opinions of the staff or owners of the Mammoth Times. Reader response is encouraged.
|
|
Last Updated ( Thursday, 21 August 2008 )
|
