IntroductionDuring summers, the oxygen content at the top of the water normally has a salinity level consistent with "more than 8 milligrams per liter"; but when the oxygen content drops to “less than 2 milligrams per liter,” the water is then known to be in a hypoxic state (CENR, 2000; USGS, 2006). Hypoxia is the result of a decrease in oxygen levels to the point where aquatic organisms can no longer survive in the water column. Organisms such as fish, shrimp, and crabs are able to evacuate the area, but wildlife that cannot move becomes stressed and/or dies. For this reason, many call the zone of hypoxia the “dead zone” (Overview, 2008; USGS, 2006). Due to agricultural fertilizers, excessive nitrogen and phosphorus can be carried away and flow into rivers. From there, marine algae blooms cause the water to turn green from chlorophyll (Reed, 2011). Eutrophication then becomes a dilemma in the system causing either an increase in primary production or an expansion of algae. An enormous expansion of phytoplankton on the water surface is then established. At the same time, the water column is also stratified, meaning things like temperature and salinity are out of sync from top to bottom. The seasonal warm surface water has a low density forming a saltier layer above while the colder, denser water masses near the lower layer are insulated from the top, cutting off the oxygen supply of the atmosphere (Overview, 2008).HistoryHypoxia is “increasing rapidly” worldwide (Briggs, 2009). Areas in the United States included the Long Island Sound, the Chesapeake Bay, and the Gulf of Mexico; off the coasts of Louisiana, Mississippi and sometimes extending to the Texas continental shelf (EPA, 2003). The Gulf of Mexico is also... middle of article ......riggs, K., Watkins, J., Shivarudrappa, S., & Hartmann, V. (2009). Effects of hypoxia on sediment properties in the northern Gulf of Mexico. 9. Stennis Space Center, MS, USA. Joyce, S. (2000). Dead zones: coastal waters deprived of oxygen. Environmental Health Perspectives, 108 (3), 6. Meade, RH (1995 ed.). Contaminants in the Mississippi River, 1987-1992. US Geological Survey Circular 1133, US Department of the Interior. Denver, CO, USA.Overview. (2008). Retrieved October 2011 from Gulf hypoxia: www.gulfhypoxia.net/overviewReed, C. (June 20, 2011). Mississippi flooding will raise the dead zone in the Gulf. Discovery News. United States Geological Survey (USGS). (2006, March). Gulf of Mexico Dead Zone - The Last 150 Years. St. Petersburg, FL, United States. US Environmental Protection Agency (EPA). (2003). Hypoxia and wetland restoration. Washington, DC, United States.