Algal blooms impart a distinct colour to water due to

Options

A. their pigments
B. excretion of coloured substances
C. formation of coloured chemicals in water facilitated by physiological degradation of algae
D. absorption of light by algal cell wall

Explanation

**Step-by-Step Solution:**

1. **Understanding Algal Blooms**: Algal blooms are rapid increases in the population of algae in aquatic environments, often due to nutrient pollution (like excess nitrogen and phosphorus).

2. **Impact on Water Color**: The distinct color imparted to water during algal blooms is primarily due to the pigments present in different types of algae.

3. **Types of Algae and Their Pigments**:
- **Green Algae**: Contains chlorophyll, which gives it a green color.
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