Water quality monitoring is essential to understanding the health of our waterways, land and people. Here are 4 simple parameters you can monitor and what they tell you about the quality of your water. 

Dissolved Oxygen

Dissolved oxygen is a key indicator of ecosystem health and is essential for the aquatic life. It can be measured in a variety of ways from field kits, like the winkler titration, to electronic probes. Low dissolved oxygen is often the result of excess nutrients in the water from land runoff, which fuels algal blooms that eventually decompose and use up large quantities of oxygen. Most problems with dissolved oxygen occur during the summer due to increased temperatures and in extreme cases, this can cause dead zones, where dissolved oxygen is so low that it cannot sustain life. 

Photo from: the UMCES-IAN symbol library.


Air and water temperatures are key indicators that can effect both biological and physical characteristics of an ecosystem, and are monitored using a thermometer. Changes in water temperature influence which plants and animals can survive in the Bay. Warmer water stimulate growth, reproduction, and decomposition of plants and animals, and decrease the dissolved oxygen available, which make it hard for plants and animals to survive. Water temperature can vary for a variety of reasons, cutting riparian areas alongside waterways is a major contributor to warmer waters. 

Photo from: the UMCES-IAN symbol library.

Water Clarity

Water clarity is a measure of how much light penetrates through the water column and can be measured using a secchi disk or turbidity tube, colorimeters and probes. Clear water is critical for the growth and survival of aquatic species, as it allows sunlight to pass through the water column to support photosynthesis and allows fish, crabs and other aquatic organisms to see the environment, catch prey and breathe. Poor water clarity is usually caused by a combination of excess suspended sediments due to runoff from land.

Photo from: https://www.indiamart.com/proddetail/secchi-disk-16675738833.html


Bacteria are microscopic organisms originating from the intestines of humans and other warm-blooded animals, they can be found in fresh and salt water. Bacteria measured in brackish and salt water are called enterococci and in fresh water are called E.coli. Bacteria can be measured using the Coliscan Easygel technique or by lab analysis. Bacteria naturally occur in fresh and salt water, however harmful bacteria from human or animal waste can enter waterways through leaking septic systems, broken sewer lines, and runoff when it rains. 

For more information about how you can get involved, visit the Chesapeake Monitoring Cooperative!