The difference between oligotrophic waters and eutrophic waters.

The best way to explain the differences between oligotrophic waters and eutrophic waters is by describing this picture:  

In the first picture there is the oligotrophic water, where the water is clear and there is a low amount of nutrients, the light can easily leak into the water and here you can find SAV or submerged aquatic vegetation. In oligotrophic waters you can find a high content of water which is supporting the lives of many species in the water. On the other hand Eutrophication is or means well nourished or well feed because this water is fulfilled with different nutrients. To understand better Eutrophication first we have to know the difference between benthic plants and phytoplankton. Benthic plants are plants which grow in the attached to in the bottom of a body of water. These are also categorized as SAV plants. Phytoplanktons are plants that grow in the surface of the water and these plants are stopping the sunlight to penetrate into the water (bottom of the lake). Phytoplankton grows as single cells or in small groups of cells and they are found whenever light and nutrients are available. So Eutrophication happens when water is being well nourished by nutrients like phosphorus or nitrogen.

The Eutrophication process begins when in oligotrophic waters nutrients like nitrogen and phosphorus are added. First the oligotrophic water is clear, the amount of nutrients is low, and the water can easily penetrate because the phytoplankton is limited. After the nutrients are added water starts to be more lumpy, phytoplankton starts to grow SAV starts to disappear. The third phase and the final phase is when Eutrophic process really happens. Now the amount of nutrients is really high and there aren’t any more SAV in the water, only phytoplankton and because now we have dead aquatic vegetation, decomposers have to do their work here so if in the water are a lot of organic waste then more oxygen is needed from the bacteria’s to do the decomposing process. Other species like fishes will suffocate because of the low amount of oxygen. This is also called Hypoxia or (oxygen depletion). 

Sources of nutrient pollution that are causing the process of Eutrophication are:

•  Agriculture sources

• Chemical fertilizes

• Manure

• Aquaculture

• Urban and industrial sources

• Fossil fuel sources