How do thermal power plants affect aquatic life?

Options

A. Increase aquatic population
B. Decrease water temperatures
C. Increase the carbon dioxide in water
D. Decrease the amount of oxygen in water

Explanation

**Step-by-Step Solution:**

1. **Understanding Thermal Power Plants**: Thermal power plants generate electricity by burning fossil fuels like coal. This process involves heavy machinery that operates continuously, which generates a significant amount of heat.

2. **Heat Generation and Cooling**: To manage the heat produced by the machinery, thermal power plants use water as a coolant. The heat from the machines is transferred to the water to maintain their efficiency.

3. **Impact on Water Temperature**: The water used as a coolant absorbs heat and becomes hot. When this heated water is discharged into nearby water bodies (like rivers or lakes), it raises the temperature of the water in those bodies.

4. **Effects of Increased Water Temperature**: The increase in water temperature affects the solubility of gases in the water. Specifically, oxygen, which is crucial for aquatic life, is less soluble in hot water than in cold water.

5. **Consequences for Aquatic Life**: As the temperature of the water increases, the amount of dissolved oxygen decreases. This reduction in oxygen availability can lead to a deficiency for aquatic plants and animals, which rely on oxygen for survival.

6. **Evaluating the Options**:
- a. Increase Aquatic Population: Incorrect, as lower oxygen levels can lead to a decrease in aquatic life.
- b. Decrease Water Temperature: Incorrect, as the water temperature actually increases.
- c. Increase the Carbon Dioxide content in Water: Incorrect, as carbon dioxide is also less soluble in hot water.
- d. Decrease the amount of Oxygen in Water: Correct, as the hot water leads to lower oxygen levels.

7. **Conclusion**: The correct answer to how thermal power plants affect aquatic life is that they decrease the amount of oxygen in water.

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