Hypoxia

GAC008Assessment Event 4: Academic Research Essay

Definition:

Man-made Environmental Issues

Student’s Name: Shirley

Student ID#:

Teacher: Anthony

Due Date: 20/11/2014

Word Count: 1316

Question: What is meant by ‘hypoxia’? Explain with reference to the severity of the problem in your own country.

In this day and age, according to a credible survey conducted by a famous international organization, an increasing number of environmental problems caused by human are damaging the Earth. One of the earth’s serious problems is ‘hypoxia’. ‘Hypoxia’ has two different definitions. The first explanation, which is the most well-known, is that the deficiency in the amount of oxygen reaching body tissues. In this situation, if not reversed quickly, hypoxia will lead to tissue die, as in heart attack (West, J. B 2008). The second definition, which will be discussed mainly in this essay, is that the condition happens when natural waters have a low concentration of dissolved oxygen (Stevenson, L.H. & Wyman, B. 1991).

First and foremost, hypoxia always causes many environmental problems and the human activities also have large influence on it. Generally, hypoxia occurs when oxygen concentrations fall below the level necessary to maintain most animal life. For a large number of the community of aquatic organisms, hypoxia is like drowning, due to the fact that the indispensable dissolved oxygen levels in the body of water drop much lower than normal. The hypoxia often occurs when high concentrations of nutrients enter water, which will cause the lake eutrophication. In addition, the hypoxia could be the result of lots of factors including natural ones, which have been observed. However, the local ecosystems have adapted to the occurrences in these cases. A typical example is the Pacific coasts of the Americas where the continental shelves end. Nevertheless, there is no doubt that human activities have increased the frequency, area and severity of hypoxia around the world....