Dead Zone isn't a remake of the Stephen King 1983 movie or the USA Television show. A dead zone, in reality, is an area of water that has been stripped of its oxygen. That means that all oxygen supported life is gone, fish, crabs, and plants a literal dead zone in a process called hypoxia.. They are created by an increase in chemical nutrients (particularly nitrogen and phosphorus) in the water. The high nutrient levels increase algae growth. The algae dies and, as it decomposes, strips the water of its oxygen. It gets a bit more complicated than that. It seems that over fishing adds to the problem. By disrupting the food chain, the creatures that eat the algae are thrown out of balance and a runaway algae plume grows.
In 2008, an international study estimated over 400 dead zones world wide including in this country. In 2005 there were 43 dead zones in the U.S. and the one in the Gulf of Mexico is the largest. It ranks second largest in the world and covers an area larger than New Jersey. Every year, approximately 1.6 million tons of nitrogen enter the Gulf from the Mississippi basin, more than triple the average flux measured between 1955 and 1970.
Almost every large river that empties into the ocean has a dead zone related to it. The Susquehanna river dumps its nutrients and chemicals into the Chesapeake bay. We don't see a problem here, but in the bay, researchers with the University of Maryland Center for Environmental Science have been battling a dead zone for more than a quarter of a century. It has been affecting the fish, crab and oyster harvest by reducing the area where they can flourish.
Even closer to home, Lake Erie has a large dead zone that stretches from Erie, PA to Sandusky, Ohio and Lake George has had 23 straight years with a dead zone. It covers almost 20% of the lake. There seems to be a relationship between the nutrient levels and the water temperature. The warmer temperatures allow the algae to flourish and spread. Then you add excess nutrients (nitrogen and phosphorus) from agriculture, air deposition, septic systems and sewage treatment plants, and runoff from lawns, gardens and paved surfaces reach the water fueling the growth of phytoplankton, or algae.
Until recently, these areas were prime fishing grounds which were naturally fed nutrients from the rivers. Now the nutrients are overwhelming areas and the natural balance is thrown off kilter allowing the algae to take over. This creates two problems. One, the algae blooms are grabbing all of the nutrients and two, it is pushing the nutrient starved fishing area further away. At the same time, there are some political figures that say humans have very little impact on our environment while every year that goes by the problem increases.
The oil disaster in the Gulf of Mexico may add to the already large dead zone. The oil will settle to the bottom and kill all of the plant and sea life. These will decompose adding to the dead zone. On the other side, there are a few scientists that the oil disaster will help to by limiting the growth of the algae. The official size of the 2010 Gulf dead zone will be announced following a NOAA-supported monitoring survey led by the Louisiana Universities Marine Consortium, July 24 through Aug. 2..
http://www.sciencedaily.com/releases/2010/06/100628124611.htm
http://www.sciencedaily.com/releases/2008/07/080714160000.htm
http://www.washingtonpost.com/wp-dyn/content/article/2008/08/14/AR2008081401910.html
http://www.timesunion.com/AspStories/story.asp?storyID=851017&category=REGION
http://www.grinningplanet.com/2005/05-17/gulf-of-mexico-dead-zone-usa-global-article.htm