Q)answer the following Q. (Based on diagram)
1)what will be effect on fishes at point A?why?
2)compare bod at point A and C .give reason.
3)compare DO at B and C.

Dear student,Fishes at point A will die due to increase in BOD. (2).At point C,BOD is lesser as compared to point A.It is because bacterias will take up all oxygen resulting in decline. (3).When BOD levels are high, dissolved oxygen (DO) levels decrease because the oxygen that is available in the water is being consumed by the bacteria.At point C,DO is higher as BOD is lesser compared to point B.Regards.