Реферат на тему The Hypoxic Zone Essay Research Paper This
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The Hypoxic Zone Essay, Research Paper
This article is about a problem with the chemistry in a large area of the Gulf of Mexico. Basically, the problem is that every spring oxygen levels in the deepest parts of the water become so depleted that most local wildlife is suffocated or flees. This part of the Gulf of Mexico is called the hypoxic zone (obviously meaning low oxygen zone).
The cause of the problem is the Mississippi River, which deposits 580 cubic kilometers of water to the Gulf every year. Not only is the Mississippi one of the 10 largest rivers in the world, it’s also likely one of the 10 most polluted. The pollution is contained mainly in the form of dissolved nitrogen and phosphorus which come not only from the Mississippi but also a main tributary, the Atchafalaya. These elements provide a fecund environment for phytoplankton at the surface, which eventually die and defecate all the way down to the bottom. Here, bacteria feast on them and oxygen, stealing it from the fish and crabs that need it.This problem has occurred in other areas, but at a far less alarming rate. The hypoxic zone has caused declining fish catches progressively for a few years now.
The hypoxic zone has been nicknamed the “dead zone” but the problem with it is too much life of the moneran sort. The sea bottom of some of the worst spots may be found covered in dead and dying animals, coated in an ugly uni-cellular colony of killers. Studies are being done to find the causes of the problem and possible solutions. It has been found that 56% of the nitrogen comes from fertilizer that seeps in through American farmland into the Mississippi and other feeder rivers. 25% comes from natural fertilizers, i.e manure, and 6% comes from city & personal wastes. Although farmers don’t like taking the blame, statistics show it falls squarely on their shoulders, and measures are being taken to balance plant growth in America with fish growth in the Gulf of Mexico.