The natural ageing of a lake is called eutrophication. In a young lake, there is very little life. Over the time, streams drain into it and water becomes enriched with nutrients like phosphate and nitrates.
As a result, phytoplanktons and some other plants flourish well. Due to this, the organic matter increases in lake, water becomes warmer and shallower. Hence, decomposers also start growing.
The high numbers of decomposers make use of large quantity of oxygen for decomposition. This leads to depletion of dissolved oxygen of the water and mortality of fish and other aquatic organisms. The eutrophied water bodies can lead to algal blooms, which further add organic matter in lake. These consume more oxygen leading to its depletion.
Answers
Amit Jindal
The natural ageing of a lake is called eutrophication. In a young lake, there is very little life. Over the time, streams drain into it and water becomes enriched with nutrients like phosphate and nitrates.
As a result, phytoplanktons and some other plants flourish well. Due to this, the organic matter increases in lake, water becomes warmer and shallower. Hence, decomposers also start growing.
The high numbers of decomposers make use of large quantity of oxygen for decomposition. This leads to depletion of dissolved oxygen of the water and mortality of fish and other aquatic organisms. The eutrophied water bodies can lead to algal blooms, which further add organic matter in lake. These consume more oxygen leading to its depletion.