When excessive agricultural fertilizer runoff carrying nitrogen and phosphorus flows into a local freshwater lake, it triggers rapid algae overgrowth. What is this destructive ecological phenomenon called?

Answer: C. Eutrophication

• Answer: C
• Explanation: Eutrophication occurs when a body of water becomes overly enriched with nutrients. This leads to massive algal blooms. When the algae die, decomposers (bacteria) consume vast amounts of dissolved oxygen to break them down, suffocating fish and creating aquatic "dead zones."

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