In water treatment, what is typically the main reason for monitoring algal blooms?

Monitoring algal blooms is primarily focused on preventing the production of harmful toxins. Algal blooms can result in the proliferation of certain species of algae that produce toxins detrimental to both aquatic life and human health. These toxins can contaminate water supplies, lead to fish kills, and pose serious risks to people who use the water for recreation or consumption. By keeping a close eye on algal blooms, water treatment facilities and environmental agencies can take proactive measures to mitigate the risks associated with these toxic substances, ensuring water quality remains safe for public use.

While the other options touch upon aspects related to water quality and ecosystem health, they do not capture the critical public health implications associated with algal blooms as effectively as preventing toxin production does. Monitoring also indirectly supports recreational and aesthetic interests, but the primary concern remains the safety of drinking water and the surrounding environment.