What is it? Water temperature impacts many of the other measurables such as pH, conductivity, and dissolved oxygen. It changes the water’s density, the water’s ability to support life, absorb gases (like CO₂), and absorb nutrients.
Why is it important? Increases in water temperature can cause some chemicals to become “soluble”: think how quickly salt dissolves in hot water versus cold water. Algae blooms and other vegetation can also grow more quickly in warmer water. This can be problematic for a number of reasons including the reduced dissolved oxygen that occurs when the blooms decompose.
What does it mean? Different temperatures attract different animal and plant species. Unusually warm water could be an indicator of algae blooms or even pollution discharge.
Water Rangers Protocol: Make sure the thermometer is submerged at least 10 cm from the surface of the water. Hold under the water for 5 minutes. You’ll know it’s ready when the temperature has remained the same for at least 30 seconds.
Pro Tip: Can’t reach the water? No problem! Use your sample cup and reacher stick to scoop up a sample. Measure and record right away as exposure to the outside air changes the water temperature.