Two types of aquatic organisms in a lake show specific growth

Two types of aquatic organisms in a lake show specific growth patterns as shown below, in a brief period of time. The lake is adjacent to an agricultural land extensively supplied with fertilisers.
two-types-of-aquatic-organisms-in-a-lake-show-specific-growth-3
Answer the questions based on the facts given above.
(i) Name Organisms depicting patterns A and B.
(ii) State the reason for the growth patterns seen in A.
(iii) Write effects of growth patterns seen above.

(i) The pattern A is depicted by microorganisms and pattern B is depicted by fishes or any other aquatic organism.
(ii) As the lake is adjacent to an agricultural land extensively supplied with fertilisers, the run-off water from the field will result in increase in nutrients of lake. Thus, number of microorganisms will rise to degrade organic matter.
(iii) As the microorganisms increase (depicted by pattern A), they result in decrease of dissolved oxygen in water thus causing decrease in number of aquatic organismis like fish, etc. (depicted by pattern B)…