Pollution and Lake Erie - Term Paper Example

With increase in population a lot of things changed for this lake. This increase gave rise to pollution in the form of human waste, sawdust, agriculture chaff, oil etc. The forests around this lake were cut down in order to get wood for construction purposes. Around 1960s the whole outlook of the lake changed due to this pollution caused mainly by industrial waste and untreated sewage. Rivers that flowed into this lake were also much polluted. This problem became so serious that warnings were given to the residents against the contact with the water.

All of this made life in this water impossible; hence, this lake was declared ‘dead’. Lake Erie is considered dead, as a consequence of eutrophication (Gilpin 1995). Lake Erie is one of the lakes in the world which has a very large dead zone. The area which lacks oxygen is called a dead zone. According to scientific researches done by scientists dead zone works in two distinct layers. There are two separate layers of water in the lake; one is on the top and the other at the bottom. Temperatures in these two layers are mostly different except in the springtime where the temperature in both layers is the same.

In summers, the water in the upper layer warms up and the bottom layer remains the same. This results in a significantly colder layer of water at the bottom of the lake. This difference in temperature between two layers is called thermocline. All the activities in the water takes place in the upper layer as all the sunlight and nutrients are present here. When the algae and animals present in the upper body die, they fall at the bottom and decomposition takes place. The process of decomposition uses up all the oxygen in these areas, hence, giving rise to dead zones.

This problem is really bad in Lake Erie because the water here is not very deep and there is less oxygen in it so the oxygen is depleted very quickly. Scientists are making efforts to reduce this problem of oxygen depletion in Lake Erie. There are a lot of nutrients present in this lake and the sources of these nutrients are divided into two categories. These categories are called point sources and non point sources. Point sources are the sources through which the nutrients that are released into the water can be measured like wastewater treatment plants.

On the other hand non point sources are the ones which cannot be measured for example agricultural runoff and the amount of fertilizers cannot be calculated accurately. It is still not possible to completely evaluate whether the dead zone is expanding or is recovering. It varies from year to year, according to the temperature. The great lakes national program office of USEPA is playing a vital role in repairing the Lake Erie. Surveys are conducted annually by these people to check the level, degree and occurrence of oxygen depletion in the lake basin.

They also track the trend in which this occurs. These also check the phosphorus level in the water so that it does not exceed its level. Phosphorus changes water chemistry and can lead to changes in water oxygen levels that eventually impact aquatic plants and animals that feed off them (Davies & Mazurek 1998). The information gathered cannot be same for every year as weather is variable that changes every year so the level of oxygen and phosphorus varies each year. To do all this data is collected and EPA research is used.

Side by side biological and geological surveys are also taken into consideration.