Which of the following is a factor affecting piscicide effectiveness?

Water temperature is a critical factor affecting the effectiveness of piscicides. The ability of piscicides to dissolve and disperse in water is significantly influenced by temperature. Warmer waters typically increase the chemical reactivity and bioavailability of piscicides, enhancing their efficacy against target fish species. In colder waters, the solubility and activity of piscicides can be diminished, which leads to reduced effectiveness in controlling fish populations.

While factors such as cold water temperature, population density of fish, and soil composition may play some role in the broader context of aquatic ecosystems, they do not directly impact the fundamental chemical interactions and processes that determine how effectively a piscicide works in a given environment. Thus, the temperature of the water remains the most influential factor in ensuring successful piscicide application and targeting the specific fish populations intended for control.