Dead ZoneSummarized from an article in the July, 2001 Scientific AmericanFirst mapped in 1985, the Dead Zone in the Gulf of Mexico has since doubled in size. It varies greatly from year to year in size and location, but it has reappeared every year. The record so far is 20,000 square kilometers (about 7500 square miles), the size in 1999. Excess nitrate - basically the runoff of too much fertilizer and sewage - is delivered to the Gulf in the spring by the Mississippi River. This feeds bacteria on the sea floor, causing them to consume oxygen faster than it can be replenished. Creatures living on the bottom suffocate and die. Winter restores the oxygen and spring brings back the nitrates. The Environmental Protection Agency did have a task force with a program to cut the size of the Dead Zone in half. This is an achievable short-term goal. However, President Bush has not appointed officials with authority to reconvene the task force. His budget to Congress included none of the roughly $1 billion needed for implementation of the program. Consequently, we can expect new records to be established for the Dead Zone in coming years. |