Question

Which of the following statements about eutrophication is true?

a. Eutrophication occurs when excess nutrients are present in aquatic ecosystems, resulting in
the increased production of plant life and the subsequent increase in the oxygen levels of the
water.
b. Eutrophication occurs when excess nutrients are present in aquatic ecosystems, resulting in
the increased production of plant life and the subsequent decrease in the oxygen levels of the
water.
Eutrophication involves the overpopulation of aquatic ecosystems with plant and animal life.
d. Eutrophication is rarely caused by human activity.

Answer 1

b

Step-by-step explanation:

Eutrophication occurs when excess nutrients like phosphorus from agricultural fertilizers are carried off into aquatic ecosystems. Since phosphorous is one of the limiting nutrients to plants, its excessive amounts result in a drastic increase in algal growth in the water system.

Step 2

As these plants decompose, a high amount of oxygen is used up resulting in a decrease in oxygen levels in the aquatic system. A very low level of oxygen in the water is detrimental to many aquatic organisms.

Result

B