Introduction:

Recently, dead zones have been increasingly considered a common phenomenon around the world, especially around continental coasts. Most simply, a dead zone is an area in the ocean that either is hypoxic, characterized by depleted oxygen levels, or anoxic, an area without any dissolved oxygen. There have been more than 400 reported dead zones covering an approximate 245,000 square kilometers. The most well known locations of dead zones include the Chesapeake Bay, the Gulf of Mexico, the Baltic Sea, the Adriatic Sea, and most recently, the Oregon Coast. Although many of these dead zone systems are only seasonally hypoxic, scientists have observed an increase in persistent, year-round hypoxia. The largest dead zone in the world in the Baltic Sea experiences persistent oxygen depletion. This observation has sparked new research as to the cause of the increasing number of dead zones. It is undeniable that human contributions, such as improper waste disposal and agricultural run-off, initially may have been the most pressing contributive factor, but in consideration of the recent exponential growth in the number of dead zones away from agricultural locations, global warming is now considered as a highly probable explanation for oceanic dead zones. In a recent study in Science Magazine, Robert J. Diaz and Rutger Rosenberg have stated that oceanic dead zones are " a key stressor to marine ecosystems" (926). The increase of dead zones has obvious environmental and socioeconomic implications. Without oxygen, marine species can no longer remain in once heavily inhabited areas in the deep ocean.  Dead zones also contribute to the diversion of the migratory patterns of aquatic and avian organisms, and pose an economic threat to communities directly and indirectly reliant on biotic oceanic resources. Further exploration and familiarization with these phenomena is imperative if we are to confront the threats they pose.