FAQs about Water Pollution and Shortage
9. What are oligotrophization and eutrophication of lakes?
When a lake or a reservoir is low in nutrients it has clear waters, it allows a great penetration of light, which prevents an abundant growth of algae and animal species (oligotrophic waters).
As it accumulates nutrients, the lake becomes eutrophic. The algae begin to reproduce in important quantities, which results in the water becoming cloudy. When the algae and other species decompose, after completing their life cycle, oxygen is consumed from the water due to bacterial activity. This process, called eutrophication, affects the reproduction of fish and other species. In some cases, anaerobic putrefaction occurs, the waters become cloudy and become inadequate for human consumption. In some ecosystems, such as lakes, the main factor in eutrophication is phosphate.