The Gulf of Mexico Hypoxia, "The Dead Zone"

Essay by hfctorchCollege, UndergraduateB+, November 2006

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Hypoxic, which means low oxygen, and anoxic, which means there is no oxygen at all, have always been present and occur mostly in the deeper environments of the oceans. However, a rise in hypoxic and anoxic waters, are on the rise in estuarine, and coastal locations in part because of an increase in activities by humans (Diaz and Rosenberg 1995). The northern part of the Gulf of Mexico contains the second largest coastal hypoxia in the world. This region is often called the "Dead Zone" because of the failure to catch fish, shrimp, and crabs (Renaud 1986). This zone has an increase of species which either become stressed or die due to the low oxygen levels for long periods of time. Ultimately this causes the habitats biodiversity to lower, and changes the normal function of the ecosystem (Rabalais et al. 2001). However, some organisms have adapted to these low or no oxygen waters, but the numbers of species who have adapted is far less than the species who have adapted (Rabaliais and Turner 2001a).

Hypoxia is a great concern. Areas affected by hypoxia are increasing each year in coastal and estuarine areas, due to an increase of nutrient over loading mostly likely caused by humans (Diaz and Rosenberg 1995). A hypoxic area is one of the conditions present in an eutrophic area. A eutrophic area occurs when a rise in nutrients, usually by phosphorus and nitrogen (Nixon 1995). This nutrient overloading is seen in areas where human populations have increased, expansion of farms along basins of rivers, and an increase in energy and food consumption (Nixon 1995). An over loading of nutrients can really ecologically effect coastal waters. It can reduce light penetration, increase macroalgae, reduction of aquatic habitat, cause hypoxia and anoxia, effect trophic reactions, and food webs (Vitousek...