Toxic algae, often referred to as harmful algal blooms (HABs), are rapid growths of algae in water bodies that produce toxins harmful to humans, animals, and the environment. These blooms can occur in freshwater and marine ecosystems, typically triggered by excess nutrients, such as nitrogen and phosphorus, from agricultural runoff or wastewater. When toxic algae bloom, they can deplete oxygen in the water, leading to dead zones where aquatic life cannot survive. Some species, like Cyanobacteria, can produce potent toxins that contaminate drinking water and affect recreational activities, posing serious health risks to both humans and wildlife.