Dead Zones

This is an example of a dead zone. This specific dead zone 

is due to the build up of sediment. This is called

a creeping dead zone. 

This came from an article claiming that humans are the cause

of dead zones globally. The article states that although dead zones

occur naturally humans play a large role. Our carelessness and 

practices may be causing dead zones. 

A dead zone, or hypoxic zone, in the ocean is a an area of low oxygen. The oxygen is so low that most organisms suffocate and die in these areas or leave. Dead zones are caused by excessive nutrient pollution from human activities coupled with other natural factors that deplete the oxygen required to support most marine life in bottom and near-bottom water. Although most animals and plants cannot live in dead zones, many species of bacteria thrive in these low oxygen areas. Dead zones occur all over the world and are completely natural but over the past 50 years there has been an increase in dead zones due to the amount of pollutants being tossed into the oceans. As  result, dead zones have ale increased in size and have thrown off the balance coastal ecosystems. The largest dead zone in the world currently is the Baltic Sea. Other dead zones include Chesapeake Bay in Oregon, Lake Erie, and the Gulf of Mexico. There have been 405 dead zones identified worldwide. There have also been studies conducted on the relation between climate change and dead zones. With the worlds general climate rising every year, the oceans will become warmer as well. Warmer water holds less oxygen which means that dead zones will begin to increase and become larger in size, killing off organisms. in the United States alone there are around 200 dead zones and only about 34 of them are from natural causes, The rest are from human pollution including sewage, irrigation runoff, chemicals, and more. In Africa and South America, sewage is the biggest issue with water pollution but researchers say that this could be a good thing because of the improvements on water sanitation and waste management solutions. Another cause of dead zones from pollution is airborne nitrogen from vehicles and power plants when they burn off fossil fuels. Nitrification is mainly an issue along the Chesapeake Bay area and in Long Island sound because of coal-burning power plants that heavily give off large amounts of nitrogen. We live near most of the dead zones in the United States. The eastern and southeastern regions of the United States contain the most dead zones. This map illustrates all of the areas of dead zones in the United State. The darker areas are the dead zones found across the country. Two reasons for more dead zones being in the eastern areas rather than the western areas are the population density and the climate of the region. There are more people, and animals, residing in the eastern parts of the country and the climate tends to be higher and more humid.