Answer:
An increase growth in microorganisms results in oxygen depletion
Explanation:
The growth of algal bloom is caused due to excessive runoff rich in the nutrients like nitrogen and phosphorous. This run off comes from the agricultural field.
These nutrients aids in the growth of the algae(microorganisms) in large number. This growth forms a layer on the water body and use the oxygen present in the water and makes the water oxygen deficient.
