The Algal bloom

Options

A. Is caused due to a large amount of nutrients in water
B. Imparts distinct colour to the water bodies
C. Causes fish mortality and deterioration of water quality
D. All of these

Answer

### Step-by-Step Solution:

1. **Understanding Algal Bloom**:
- Algal bloom refers to the rapid increase or accumulation of algae in water bodies, often resulting in a green or blue-green coloration of the water.

2. **Causes of Algal Bloom**:
- The primary cause of algal bloom is the presence of excessive nutrients, particularly nitrogen and phosphorus, in the water. These nutrients often come from agricultural runoff, wastewater discharge, and other human activities.

3. **Effects of Algal Bloom**:
- Algal blooms can impart a distinct color to the water body, making it appear green, blue, or even red depending on the type of algae.
- They can lead to fish mortality due to the depletion of oxygen in the water when the algae die and decompose.
- Algal blooms can also deteriorate water quality, making it unsuitable for drinking, recreation, and aquatic life.

4. **Evaluating Statements**:
- Statement 1: "It causes due to large amount of nutrients in water." - True
- Statement 2: "Imparts distinct color to the water body." - True
- Statement 3: "Causes fish mortality and deterioration of water quality." - True

5. **Conclusion**:
- Since all the statements regarding algal bloom are true, the correct answer to the question is option D: "All of these."