Free-floating algae are called algal blooms.

Answer

**Step-by-Step Solution:**

1. **Understanding Algal Blooms**:
- Algal blooms refer to the rapid increase or accumulation of algae in water bodies, often due to nutrient overload, particularly nitrogen and phosphorus.

2. **Formation of Algal Blooms**:
- These blooms occur when there is an excessive amount of nutrients in the water, which can come from agricultural runoff, wastewater discharge, or other sources.

3. **Characteristics of Algal Blooms**:
- Algal blooms are primarily composed of planktonic algae, which are microscopic organisms that float in the water. They are non-motile, meaning they do not swim but are carried by water currents.

4. **Impact on Water Quality**:
- As these algae proliferate, they consume dissolved oxygen in the water, leading to decreased oxygen levels, which can harm aquatic life. This phenomenon is measured by Biological Oxygen Demand (BOD), which increases as the algae grow and deplete oxygen.

5. **Conclusion on the Statement**:
- The statement "Free-floating algae are called algal blooms" is true. Algal blooms consist of free-floating algae that thrive in nutrient-rich waters.

**Final Answer**: The statement is true.

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