What is the primary concern regarding blue-green algae?

The primary concern regarding blue-green algae is their potential toxicity to aquatic life. Blue-green algae, also known as cyanobacteria, can produce harmful toxins that can have detrimental effects on fish, invertebrates, and other aquatic organisms. These toxins can disrupt the respiratory and nervous systems of aquatic species, leading to illness or death.

In addition to aquatic life, these toxins can also pose risks to human health if contaminated water is ingested or if individuals come into contact with toxin-laden water during recreational activities. Awareness of these risks is crucial in the management and prevention of harmful algal blooms, which often form under nutrient-rich conditions, particularly in warm or stagnant water bodies.

In contrast, blue-green algae do not thrive in cold water, they don't require sand for growth (they can grow in various substrates), and they certainly are not completely harmless given their potential to produce toxins. Understanding the ecology and behavior of blue-green algae is essential for effective aquatic weed management practices.