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Solvency---Reversible Dead Zones can be reveres- empirics from the Black Sea prove
Biello, David. "Oceanic Dead Zones Continue to Spread." Scientific American Global RSS. Scientific American, 15 Aug. 2008. Web. 16 July 2014. .
"More than 212,000 metric tons [235,000 tons] of food is lost to hypoxia in the Gulf of Mexico," says marine biologist Robert Diaz of The College of William & Mary in Williamsburg, Va., who surveyed the dead zones along with marine ecologist Rutger Rosenberg of the University of Gothenburg in Sweden. "That's enough to feed 75 percent of the average brown shrimp harvest from the Louisiana gulf. If there was no hypoxia and there was that much more food, don't you think the shrimp and crabs would be happier? They would certainly be fatter."¶ Only a few dead zones have ever recovered, such as the Black Sea, which rebounded quickly in the 1990s with the collapse of the Soviet Union and a massive reduction in fertilizer runoff from fields in Russia and Ukraine. Fertilizer contains large amounts of nitrogen, and it runs off of agricultural fields in water and into rivers, and eventually into oceans.¶ This fertilizer runoff, instead of contributing to more corn or wheat, feeds massive algae blooms in the coastal oceans. This algae, in turn, dies and sinks to the bottom where it is consumed by microbes, which consume oxygen in the process. More algae means more oxygen-burning, and thereby less oxygen in the water, resulting in a massive flight by those fish, crustaceans and other ocean-dwellers able to relocate as well as the mass death of immobile creatures, such as clams or other bottom-dwellers. And that's when the microbes that thrive in oxygen-free environments take over, forming vast bacterial mats that produce hydrogen sulfide, a toxic gas.¶ "The primary culprit in marine environments is nitrogen and, nowadays, the biggest contributor of nitrogen to marine systems is agriculture. It's the same scenario all over the world," Diaz says. "Farmers are not doing it on purpose. They'd prefer to have it stick on the land."
And- San Francisco bay also proves- it can be reversed through removal of nutrients through natural processes or OMEGA
Perlman, David. "Scientists Alarmed by Ocean Dead-zone Growth." SFGate. SFGate, 15 Aug. 2008. Web. 13 July 2014. .
Hypoxia is caused by tons of nitrogen and phosphorus in fertilizers that run from farms and spill into the seas from rivers and streams as well as by fallout from power plants that burn fossil fuels.¶ The chemicals become prime nutrients that fertilize rich blooms of microscopic algae near the surface layers of coastal waters. The algae eventually die, sink to the bottom layers of the ocean and become food for masses of bacteria that decompose and consume the oxygen around them. The result is the dead zone, devoid of most marine life forms.¶ The largest dead zone on Earth is in the Baltic Sea, according to the survey, and the largest in the United States lies at the mouth of the Mississippi River, where the water is "hypoxic" over an area of 8,500 square miles - roughly the size of New Jersey.¶ The scientists found only a few small dead zones along the California coast and none in San Francisco Bay now, an improvement over previous eras when conditions made it impossible for marine life to thrive there.¶ That was during the 1950s through the 1970s, said James E. Cloern , a marine biologist at the U.S. Geological Survey in Menlo Park who has been monitoring the bay's health for more than 30 years.¶ The problem then, Cloern said, was the result of continuous discharges of poorly treated sewage from communities surrounding the bay and wastes from many cannery plants. But the issues were resolved when waste treatment facilities were updated all around the bay, he said.¶ San Francisco Bay also benefits from "strong tidal action" that mixes the water and also supports active communities of clams and mussels that help keep anything like a dead zone from developing, Cloern said.¶ "But things can change, and there's no guarantee that we won't be seeing blooms of algae in the future here, too, so we need to be really vigilant," he said.¶ According to Diaz's survey, the few dead spots along the California coast develop only periodically where water circulation is limited. They include the inland portion of Elkhorn Slough near Moss Landing in Monterey County and Alamitos Bay at the mouth of the San Gabriel River near Long Beach.¶ Diaz's institute is part of the College of William and Mary in Williamsburg, Va., and he has been surveying the world's dead zones, starting with nearby Chesapeake Bay, for more than 20 years.¶ Jane Lubchenco, former president of the American Association for the Advancement of Science and a leading marine biologist on ocean ecology at Oregon State University, said by e-mail that the report is "a sobering documentation of the growing threat of nutrient pollution in coastal waters around the world."¶ "The conclusion is inescapable that dead zones are now a key stressor in coastal waters," she said.¶ But she added that the problem is solvable.¶ "The evidence suggests that if the spigot of nutrients can be turned off, coastal systems can recover," she said. "Doing it can be accomplished by using fertilizers more efficiently, preventing human and animal sewage from entering rivers, and replanting vegetation (along riverbanks) to absorb excess nutrients."¶ Diaz and Rosenberg cited the Black Sea as an example of the improvements that can be made when solutions are applied. Until the 1990s, the shallow northwest continental shelf there was a major dead zone, but then nutrients declined as fertilizer use diminished for several years.
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