Dead zones, facts and information. Large zones of low-oxygen water—dead zones—form annually in the Gulf of Mexico, as well as many other areas around the world.
How is the dead zone formed?
Dead zones occur because of a process called eutrophication, which happens when a body of water gets too many nutrients, such as phosphorus and nitrogen. Human activities are the main cause of these excess nutrients being washed into the ocean. For this reason, dead zones are often located near inhabited coastlines.
Where is the dead zone found?
Dead zones occur in coastal areas around the nation and in the Great Lakes — no part of the country or the world is immune. The second largest dead zone in the world is located in the U.S., in the northern Gulf of Mexico.