Tennessee Wastewater Operator Practice Exam

During which season are cyanobacteria blooms most likely to occur?

1. Spring

2. Summer

3. Autumn

4. Winter

The correct answer is: Autumn

Cyanobacteria blooms are most likely to occur during the summer season. This is primarily due to the warm temperatures, longer daylight hours, and increased sunlight that create optimal growth conditions for these organisms. During summer, nutrient levels in the waterbody, often from runoff, can also increase due to rainfall and agricultural activities, further fueling the reproduction of cyanobacteria. In contrast, spring may see the initial growth of algae as temperatures begin to rise, but it is the summer that typically provides the sustained warmth and light needed for significant blooms. Autumn presents cooler temperatures and diminishing light, which are not conducive to the rapid growth of cyanobacteria, while winter's cold conditions virtually halt their activity. Thus, summer is recognized as the peak period for cyanobacteria blooms due to the combination of environmental factors that favor their proliferation.