Question

You are studying with a classmate, who explains that increasing the amount of nutrients in a lake helps submerged, rooted aquatic plants by providing them with the nitrogen and phosphorus they need to survive and reproduce. Which of the following should be your response to your study buddy?

A-You agree because all organisms need nitrogen and phosphorus, and waterways are naturally limited in those nutrients.B-You agree and point out that plants also benefit because the decrease in oxygen will kill aquatic fish and snails, some of which would otherwise eat the aquatic plants.C-You agree and point out that the resulting fish kill would further enhance the nitrogen and phosphorus levels in the lake, which would further enhance the growth of submerged aquatic plants, creating a positive feedback loop.D-You disagree and explain that plants cannot use the nutrients in the water because the plants do not have access to the nutrients.E-You disagree because the resulting increase in phytoplankton at the surface would inhibit sunlight from penetrating into the water, thus inhibiting photosynthesis in the submerged plants.

Answer 1

E-You disagree because the resulting increase in phytoplankton at the surface would inhibit sunlight from penetrating into the water, thus inhibiting photosynthesis in the submerged plants.

Step-by-step explanation:

Eutrophication is the process wherein nutrients specifically phosphorus and nitrogen are present in excess in a water body such as a lake. The increased concentration of nutrients promoter the growth of cyanobacteria and algae such as phytoplankton.

The increased population of phytoplankton in surface water reduces the oxygen availability and clarity of water for the organisms present in deeper layers. Also, reduced clarity of water limits the amount of solar radiations penetrating the surface water to reach the deeper layers.

Increased nutrient levels of the lake would rather inhibit the growth of submerged plants due to reduced availability of sunlight as caused by presence of phytoplankton in surface water.