Tennessee Wastewater Operator Practice Exam

Duckweed primarily competes with algae for which resource?

1. Nutrients

2. Space

3. Sunlight

4. Water

The correct answer is: Sunlight

Duckweed primarily competes with algae for sunlight. This floating aquatic plant, which can proliferate rapidly in nutrient-rich waters, occupies the water's surface, creating a canopy that can block sunlight from reaching other organisms below, including algae. Sunlight is essential for photosynthesis, a process both duckweed and algae rely on for growth. When duckweed covers the surface of a water body, it limits the amount of sunlight penetrating into the water, which can constrain the growth of algae that are trying to utilize that same sunlight. This dynamic can lead to changes in the ecosystem, as the presence of duckweed may restrict algae growth due to competition for light rather than nutrients or space.