FROM: Victor Grigorov, The Environmentalist
DATE: Sep 11th, 2010
SUBJECT: DEAD ZONES AROUND THE WORLD
Dead zones have naturally been occurring on this planet for a very long time. Nevertheless, they have never been occurring so quickly, and at such unprecedented scales. So what are they? They occur in bodies of water where amounts of oxygen are exceptionally small or non-existent. Those places can usually be found near the coastlines of well-developed countries, or stale lakes and slow moving rivers. Their sizes may vary dramatically. From a few square miles, to bodies of water greater than 45,000 square miles (MSNBC, 2004). They have been reported to affect more than 400 water systems, and have a total size of more than 152,000 square miles (Diaz & Rosenberg). Areas that have been greatly affected are mostly on the East Coast of the United States, and in Western Europe (Mee, 2006). Countries like the US, England, Germany, France, Spain, Japan, and Poland seem to have the most affected coastlines. How exactly they occur can differ from place to place, but most of them lead back to one specific source, us, humans.
Although they can occur naturally on the planet, most of them are anthropogenic. Most scientist today agree that they have been formed through a process called eutrophication, “the over enrichment of the sea by nutrients (principally compounds containing nitrogen and phosphorus) that promote plant growth” (Mee, 2006). These nutrients run off and are absorbed by bodies of water, thus causing an exponential expansion of algae. This in turn causes the water to turn green and/or brown, and when this occurs, sunlight cannot reach the bottom of that body of water. Plants that produce the oxygen and help feed the marine life, simply die off, due to the lack of sunlight to produce oxygen. And when that happens, crabs, fish, and oysters are wiped off, thus creating what we now call a “dead zone”. These dead zones have been...