Fauna Journal Entry
Gulf of Mexico Dead Zone Grows (March 17, 2008)
Algae growth may signal a "dead" zone where oxygen levels are low. The mouth of the Mississippi River is one oxygen-poor zone. NASA.
The oxygen-starved "dead" zone in the Gulf of Mexico is growing. The lifeless zone stretches from the mouth of the Mississippi River to the Texas border. It now covers an area of nearly 8,000 square miles (20,000 square kilometers).
A dead zone is a coastal area where huge amounts of farm wastes, industrial pollution, and city runoff get dumped into the water. This triggers a chain reaction that robs water of oxygen and makes it harder for living things to survive.
The pollutants provide nutrients that feed the growth of algae. As the algae dies and decays, bacteria levels increase. The bacteria gobble up much of the ocean's oxygen. This kills fish and other marine organisms. It also hurts people that depend on these resources for food or to make a living.
It's not just a problem for the United States. Dead zones have appeared off the coasts of South America, Britain, China, Japan, Portugal, Ghana, Australia, and New Zealand in recent years. According to the United Nations Environment Program, there are now 200 dead zones worldwide. This is one-third more than there were just two years ago.
