• Eutrophication, naturally is both prominent in fresh water bodies like lakes & rivers and large salt water bodies like seas & oceans.

• Lakes and rivers generally experience Eutrophication because of increased phosphorous levels and Seas & oceans because of increased Nitrogen levels.

• Lakes: Classified based on the nutrient content present in them and production of organic matter:

1. Oligotrophic- Less nutrients- In low nutrient medium, life is also less
2. Mesotrophic - Not many nutrients and not very less nutrients
3. Eutrophic- High nutrients- some lakes naturally have higher contents of nutrients

• In some water bodies, waste released from the living entities present inside them, rain water, atmospheric nitrogen etc., add to the excess nutrients that constitute Eutrophication.

• Takes a long time for the water body to get polluted to a considerable extent.

• Factors like availability of light and other resources too influence the growth of unnecessary algae and other organisms that are responsible for Eutrophication-only if it is a long natural process.

• But because of Human interference and the extent of pollution that is going on now, it would take less than a century for even a large body to get succumbed to Eutrophication.

Cultural Eutrophication

• Release of pollutants into water which increase the nutrient concentration.

• Many ways:

1. Sewage disposal in water
2. Industrial waste disposal in water
3. Fertilizers and pesticides dissolved in water being channelized into water bodies
4. Organic fertilizers too can cause Eutrophication
5. Dissolution of pollutant particles on surface in rain water and flowing into water bodies