A Very Big Dead Zone
June 19, 2013 09:30 AM - Andy Soos, ENN
Dead zones are hypoxic (low-oxygen) areas in the world's oceans and large lakes, caused by excessive nutrient pollution from human activities coupled with other factors that deplete the oxygen required to support most marine life in bottom and near-bottom water. In the 1970s oceanographers began noting increased instances of dead zones. These occur near inhabited coastlines, where aquatic life is most concentrated. The vast middle portions of the oceans, which naturally have little life, are not considered dead zones. Scientists are expecting a very large dead zone in the Gulf of Mexico and a smaller than average hypoxic level in the Chesapeake Bay this year, based on several NOAA-supported forecast models. NOAA-supported modelers at the University of Michigan, Louisiana State University, and the Louisiana Universities Marine Consortium are forecasting that this year's Gulf of Mexico hypoxic dead zone will be between 7,286 and 8,561 square miles which could place it among the ten largest recorded. That would range from an area the size of Connecticut, Rhode Island and the District of Columbia combined on the low end to the New Jersey on the upper end. The high estimate would exceed the largest ever reported, 8,481 square miles in 2002.