What factor contributes to a decrease in electrofishing effectiveness as water temperature rises above 16°C?

As water temperature rises above 16°C, the increased conductivity in water has a significant impact on electrofishing effectiveness. This is primarily because higher temperatures can lead to increased ionization and a greater number of dissolved ions in the water. Conductivity refers to the water's ability to conduct electric current, which is influenced by the presence of dissolved salts and minerals.

When water conductivity is high, the electric field established between the electrodes becomes altered, often requiring lower voltage settings to achieve effective capture. As conductivity increases, the efficiency of the electric field diminishes, making it harder for the electrofishing equipment to effectively stun the fish. This change can lead to reduced capture rates, as fish may not respond in the same way to the electric field at elevated conductivity levels compared to lower conductivity conditions.