Question

How does eutrophication contribute to the aging of a lake?

• A. By increasing water temperature
• B. By reducing the growth of aquatic organisms
• C. By reducing nutrient content in water
• D. By causing depletion of dissolved oxygen

Answer 1

Answer:

D. By causing depletion of dissolved oxygen

Eutrophication

• Eutrophication is the process by which a body of water, such as a lake or pond, becomes enriched with nutrients, particularly phosphorus and nitrogen.
• This enrichment leads to an excessive growth of algae and other aquatic plants.

The increased plant growth can result in several negative effects on the water body including :

Algal Blooms:

• The overabundance of nutrients stimulates the rapid growth of algae.
• This can lead to the formation of algal blooms, where large populations of algae accumulate on the water's surface.

Reduced Oxygen Levels:

• As the algae and other plants die and decompose, bacteria break down the organic matter.
• This process consumes oxygen from the water.
• In areas with intense algal growth, the demand for oxygen can exceed the supply, leading to reduced oxygen levels in the water.
• Low oxygen levels can be harmful to fish and other aquatic organisms.
• The altered nutrient levels and oxygen concentrations can favor certain species of plants and animals over others, leading to changes in the overall composition of the aquatic ecosystem.
• Thus,Eutrophication can contribute to a decline in biodiversity as some species may thrive in nutrient-rich conditions while others are negatively impacted.