Question

Explain any two harmful activities of Blue-Green algae.

Answer 1

• Heavy accumulation of blue-green algae in water bodies bring algal bloom. Algal bloom makes water unfit for domestic use. After the death of these algae their dead organic matter creates rich source of food for aerobic bacteria. They decompose organic matter by consuming O₂. It creates O₂ deficit and causes the death of fishes.
• Some cyanobacteria grow on buildings during rainy season and cause damage to bricks and surface coating