Gulf of Mexico Dead Zone Facts

Gulf of Mexico Dead Zone Facts
The Gulf of Mexico dead zone is an area in the Gulf of Mexico where excessive pollution has resulted in an inadequate level of oxygen needed to support life. Dead zones occur where aquatic life is more concentrated, in areas with coastlines inhabited by humans. Despite the ocean's middle portions being sparsely populated by aquatic life, these regions are not considered dead zones. There are approximately 405 known dead zones in the world's oceans today, with the Gulf of Mexico's dead zone being the largest recurring hypoxic zone on earth. Hypoxic means low-oxygen, and this dead zone in particular occurs each summer for several weeks.
Interesting Gulf of Mexico Dead Zone Facts:
The first time the Gulf of Mexico's dead zone was reported was in 1950. It wasn't until 1970, when its size had grown considerably that it became the subject of scientific research.
During the years of heavy rainfall the size of the Gulf of Mexico's dead zone increases and when there is drought or decreased rainfall the dead zone is smaller.
In 1988 the Gulf of Mexico's dead zone was only 15 square miles (a record low), and in 2002 it reached 8,400 square miles (record high) in size.
Contaminants that cause the appearance of dead zones in the world's oceans can originate from lawn care (use of pesticides and fertilizers), farm land (agricultural chemical use), and sewage treatment plants. As these toxins reach the Mississippi River due to heavy rain and melting snow, they are washed into the Gulf of Mexico.
Dead zones in the Gulf of Mexico can be devastating to the fishing industry. It is estimated that 40% of the seafood in the United States originates in the Gulf of Mexico.
When a dead zone occurs aquatic life moves further out to sea, where fisherman must follow to make their catch.
Methods to reduce dead zones include reducing or eliminating fertilizer use, stopping animal waste from reaching waterways, ensuring that sewage treatment plants and septic systems are working properly, and limiting or eliminating the chemicals and organic matter from manufacturers' plants being discharged into the environment.
Wetlands along the coast of known dead zone areas can help filter water before it reaches the ocean.
When too many nutrients (such as phosphorus and nitrogen) reach the waters in the Gulf of Mexico an algae bloom occurs. This results in an environment that does not support aquatic life.
While most dead zones are the result of human pollution they can occur from changes in water and wind circulation and coastal upswelling.
Some of the more well-known dead zones in the world include the Gulf of Mexico dead zone, the Baltic Sea dead zone, the Black Sea dead zone, in Lake Erie (one of the freshwater lakes of the Great Lakes), off the coast or Oregon, and in Chesapeake Bay.
Dead zones can be reversed with proper environmental efforts. The dead zone in the Black Sea disappeared in 1991 when fertilizer use diminished greatly because of its high cost. This dead zone reversal was not intentional but it has been helpful in providing influence in reversing other dead zones.

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