Which factor is NOT a contributor to algal bloom formation?

High levels of chlorine are not a known contributor to the formation of algal blooms. Algal blooms typically occur in conditions that favor algal growth, which are often characterized by an abundance of nutrients, particularly nitrogen and phosphorus, as well as favorable environmental conditions like ample sunlight and appropriate water temperatures.

Nutrient runoff, especially from agricultural fertilizers, contributes significantly to algal blooms since the excess nutrients stimulate rapid algal growth. Similarly, increased sunlight and warmer water temperatures create ideal conditions for algae to thrive. While chlorine is used for water disinfection and control of pathogens, it does not promote algal growth in the same way that nutrients and environmental conditions do. In fact, chlorine may even inhibit algal growth temporarily; therefore, it does not play a role in the development of algal blooms.