Eutrophication includes all except

Options

A. Heavy growth of BGA
B. Decreased DO
C. Death of aquatic organisms
D. Soil erosion

Answer

**Step-by-Step Solution:**

1. **Understand Eutrophication**: Eutrophication is the process of over-enrichment of water bodies with nutrients, particularly nitrogen and phosphorus, often due to runoff from fertilizers or sewage.

2. **Identify the Effects of Eutrophication**:
- **Heavy Growth of Blue Green Algae (BGA)**: The excess nutrients lead to algal blooms, particularly blue-green algae, which thrive in nutrient-rich waters.
- **Decreased Dissolved Oxygen**: As the algae die and decompose, bacteria break down the organic matter, consuming oxygen in the process, which leads to lower levels of dissolved oxygen in the water.
- **Death of Aquatic Organisms**: The depletion of dissolved oxygen can result in the death of fish and other aquatic organisms that rely on oxygen for survival.

3. **Analyze the Options**:
- **Option 1: Heavy Growth of BGA**: This is a characteristic of eutrophication.
- **Option 2: Decreased Dissolved Oxygen**: This is also a result of eutrophication.
- **Option 3: Death of Aquatic Organisms**: This is another consequence of eutrophication.
- **Option 4: Soil Erosion**: This is not a direct effect of eutrophication.

4. **Conclusion**: Since options 1, 2, and 3 are all effects of eutrophication, the correct answer to the question "Eutrophication includes all except" is **Option 4: Soil Erosion**.

**Final Answer**: Eutrophication includes all except soil erosion.

---