What is pH?
pH stands for “potential of hydrogen,” or “power of hydrogen.” There are many definitions actually, ranging from English, to Latin to German. The pH scale was designed in 1909 by a Danish scientist and measures the acidity or alkalinity of a solution. The scale ranges from 0-14, with the number 7 indicating a neutral solution (like our blood). The low numbers from 1-6 are the acids, and 8-14 is basic (or alkaline). For example, vinegar is a about a 3 on the pH scale, while ammonia is a 12. Aquatic (and soil) organisms have a range of tolerance for how much acidity or alkalinity they can live in and be healthy. A range of 6.5-8 is the normal healthy range most living things can live within. Your pH data table in the journal has some examples of these organisms and ranges listed on the pH scale.
Why is pH important?
Testing the pH of your water sample can show you a lot about the health of the watershed and what you’d expect to find there. No pH result is “bad” per say…it’s all a matter of what an organism can handle to be comfortable. Generally however, the numbers on the extreme ends of the scale (extremely acidic or basic) do not support life. Living organisms usually prefer the middle of the road approach to chemical balance. Aquatic or semi-aquatic organisms are more susceptible to chemical imbalances because of their fluid environment and sensitive physiology. Knowing the pH of your waterway in conjunction with identifying macroinvertebrates can tell you a lot about the health of the watershed.