Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
Eutrophication results in the death of trout and other fish as a result of:
A
increased water temperature from algal blooms
B
increased predation by aquatic insects
C
decreased oxygen levels due to increased decomposition
D
direct toxicity of fertilizers to fish
Verified step by step guidance
1
Understand the concept of eutrophication: Eutrophication is the process by which a body of water becomes overly enriched with nutrients, such as nitrogen and phosphorus, often due to runoff from agricultural or urban areas. This leads to excessive growth of algae (algal blooms).
Recognize the role of algal blooms: Algal blooms block sunlight from reaching underwater plants, disrupting the aquatic ecosystem. When the algae die, they sink to the bottom and decompose, which consumes oxygen in the water.
Connect decomposition to oxygen levels: The decomposition of dead algae by bacteria is an oxygen-intensive process. This leads to a significant decrease in dissolved oxygen levels in the water, a condition known as hypoxia.
Relate oxygen levels to fish survival: Fish like trout require high levels of dissolved oxygen to survive. When oxygen levels drop due to increased decomposition, fish may suffocate and die.
Eliminate incorrect options: Increased water temperature from algal blooms, increased predation by aquatic insects, and direct toxicity of fertilizers to fish are not the primary causes of fish death in eutrophication. The correct explanation is decreased oxygen levels due to increased decomposition.