Cyanobacteria, commonly known as blue-green algae, possess numerous advantages in the natural aquatic ecosystem. They are efficient at fixing nitrogen, which can enhance the fertility of surrounding organisms. Additionally, they produce oxygen and carbon dioxide like other organisms. Nevertheless, blue-green algae can threaten humans, as they can produce toxins that are harmful to both humans and animals when ingested in large amounts. In severe cases, these toxins can even lead to death.