A large number of fish are suddenly found floating dead on a lake. There is no evidence of toxic dum

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Gujarati

Hindi

Environmental Study

easy

A large number of fish are suddenly found floating dead on a lake. There is no evidence of toxic dumping but you find an abundance of phytoplankton. Suggest a reason for the fish kill.

Option A

Option B

Option C

Option D

Solution

The amount of soluble oxygen in the water is very low. Due to the decpening of microorganisms in water, soluble oxygen decrcases. Because the microbes contained in water are disinfected by bacteria. They require very high amount of oxygen for their decomposition. SO it uses soluble oxygen in water and due to this the $BOD$ value of water goes below $6$and due to this more fishes die.

Standard 11

Chemistry