Researchers report that for the first time, they are finding areas of extremely low oxygenated water, called "dead zones" off the coast of Africa. The dead zone just measured contains less oxygen than any previously recorded. Dead zones are so named because, low in both oxygen and salinity, within them fish cannot survive and suffer massive die-offs, especially when dead zones approach coastal areas. Virtually no sea life can survive in the one just found off the coast of southern Africa, and, unusual for these formations, it is moving, destroying all life in its path.
First reported in 2010, dead zones form slow moving vortexes that travel with the earth’s rotation, and not surprisingly, have previously been found in their most heavy concentration along the coast of Central Europe and off the Eastern Seaboard of North America, with the largest on record having been documented in the Gulf of Mexico in 2013 by the Environmental Protection Agency as measuring 5,800 square miles. It is yet unknown how dead zones will affect microorganisms, but they ravage all larger marine life.
Dead zones are largely caused by farming runoff. The largest is located in the Gulf of Mexico off the Mississippi Delta, a result of massive quantities of nitrogenated water pouring into the gulf from the river. Most dead zones are stationary, fed by runoff from rivers that receive nitrogen fertilizer from farms. The African zone is the first that has been observed to be in motion, and the reason for this is not yet understood.