The health of our waterways is not determined by their clarity. Although most people would feel more comfortable swimming in a crystal clear creek; just because that creek is clear, does not mean it’s clean. The true, comprehensive measurement of water health is called water quality.
Community scientists, watershed organizations, and others measure water quality by testing a number of different chemical, physical, and biological parameters. Some of those are pH, salinity (salt concentration), turbidity (visible sediment suspended in the water), temperature, dissolved oxygen, bacteria, and more. How a waterway scores in these categories determines the fate of how people can use it, if at all, for purposes such as fishing, recreation, and drinking water.
These measurements also provide implications for the aquatic ecosystem’s health. For example, many fish and macroinvertebrate species require high levels of dissolved oxygen and low water temperatures to survive. These species are often what we call “indicator species,” because the species’ presence most likely means good water quality.

Infographic Credit: University of Maryland Center for Environmental Science

The only way we know if our streams and rivers are improving is by measuring their water quality. Community scientists and volunteers are so important to improving the Chesapeake Bay; getting their muck boots dirty, sticking their hands in the stream, testing water samples, and gathering data necessary for watershed restoration.
Want to become a community scientist with the Alliance? Learn more about the Alliance’s Chesapeake Monitoring Cooperative and RiverTrends program here.