Which type of algae is NOT affected by aeration methods?

Filamentous algae are a type of algae known for their long, thread-like structures and are commonly found in freshwater environments. They can thrive in conditions where there is enough nutrient availability and light. Aeration methods, which involve increasing the oxygen concentration in water bodies, often target other forms of algae, making it a suitable method for managing their growth.

In contrast, blue-green algae, commonly referred to as cyanobacteria, often bloom in nutrient-rich conditions and can sometimes produce toxins, which means they can be influenced by various management techniques including aeration, although with varying degrees of effectiveness. Green algae are often affected by aeration as the added oxygen can enhance their growth, sometimes leading to algal blooms. Red algae, while typically found in marine environments, can also be impacted by changes in oxygen levels and nutrient concentrations in water bodies.

Thus, filamentous algae typically exhibit a level of resilience to aeration methods, as these methods may not significantly disrupt their growth or habitat compared to the other types mentioned. This characteristic explains why they are not significantly affected by aeration techniques aimed at controlling algae blooms.