Causes of water bloom is :

Options

A. Green algae
B. Blue green algae
C. Bacteria
D. Hydrilla

Answer

**Step-by-Step Solution:**

1. **Understand the Term "Water Bloom":**
- Water bloom is commonly referred to as "algal bloom." It is characterized by a rapid increase in the population of algae in aquatic environments.

2. **Identify the Organisms Involved:**
- The organisms primarily responsible for water bloom are blue-green algae, which are scientifically known as cyanobacteria.

3. **Recognize the Conditions for Algal Bloom:**
- Algal blooms typically occur in both freshwater and marine ecosystems. They can be triggered by various factors, including nutrient pollution (especially nitrogen and phosphorus), warm temperatures, and sunlight.

4. **Conclude the Answer:**
- Since the question asks for the cause of water bloom, the correct answer is blue-green algae (cyanobacteria).

**Final Answer:**
- The cause of water bloom is blue-green algae (cyanobacteria).

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