Conductivity measures the ability of water to conduct an electrical current, which is directly related to the concentration of dissolved ions (such as salts, minerals, and other inorganic compounds). High conductivity can indicate pollution from industrial discharges, agricultural runoff, or urban development.
Aquatic organisms are adapted to specific ranges of conductivity. Significant deviations from these ranges can stress or harm aquatic life, affecting species' composition and biodiversity.
Conductivity can be an indirect measure of nutrient levels in the water. High levels of nutrients (nitrates and phosphates), often from agricultural runoff, can increase conductivity and lead to eutrophication, which depletes oxygen levels and harms aquatic life.