Which factor is most likely to increase the risk of harmful algal blooms?

The most significant factor that increases the risk of harmful algal blooms is increased nutrient runoff. This process typically involves the introduction of excess nutrients, particularly nitrogen and phosphorus, into water bodies. Nutrient runoff often arises from agricultural practices, urban development, and wastewater discharge, leading to nutrient enrichment of aquatic ecosystems.

When nutrient levels become elevated, they create favorable conditions for the rapid growth of algae, especially cyanobacteria, which can lead to harmful algal blooms. These blooms can produce toxins harmful to aquatic life, humans, and animals, resulting in a range of environmental and public health issues.

Nutrient runoff disrupts the natural balance of ecosystems, making it a critical aspect of water quality management and a primary focus for those studying and addressing algal blooms. It is essential to implement practices that reduce nutrient loading to mitigate these blooms and protect aquatic environments.