What is eutrophication?

1. Analyze the Question

The question asks for the definition of eutrophication. This is a common topic in Chemistry (under Environmental Chemistry) and Biology, focusing on water pollution and the impact of human activities on aquatic ecosystems.

2. Explain the Concept

Eutrophication is a process that occurs when a body of water becomes overly enriched with minerals and nutrients, particularly nitrates and phosphates.

• The Process: When fertilizers from farms or detergents from sewage runoff enter a water body, they act as "food" for aquatic plants.
• The Result: This leads to a rapid, uncontrolled growth of algae (an "algal bloom").
• The Consequence: As the algae die and decompose, bacteria consume the dissolved oxygen in the water. This creates an oxygen-depleted environment (hypoxia), which kills fish and other aquatic organisms, effectively destroying the ecosystem.

3. Show the Solution

• Option A: This describes general chemical pollution, which is too broad.
• Option B: This accurately describes the biological result of nutrient enrichment (algal bloom), which is the definition of eutrophication.
• Option C: This refers to heavy metal poisoning (like mercury or lead pollution), not eutrophication.
• Option D: This refers to oil pollution, which blocks oxygen from entering the water but is not caused by nutrient enrichment.

4. Identify the Answer

The correct definition of eutrophication is the excessive growth of algae caused by an influx of nutrients. This matches Option B.

5. Exam Tip

To remember this for your JAMB exam, think of the word "Nutrient-rich". Eutrophication = Excessive Uncontrolled Thriving of algae due to Nutrients. If you see "nitrates" or "phosphates" in a question about water pollution, the answer is almost always related to eutrophication!