"No water, no life. No blue, no green." — Sylvia Earle
The Tennessee River Gorge Trust established a water quality program in late 2015 to monitor perennial streams in the Gorge. We partnered with the Tennessee Aquarium and GA Adopt-A-Stream to certify five Trust staff and interns as chemical and macroinvertebrate monitors. We have begun monthly testing for stream pH levels, dissolved oxygen, temperature, fecal coliforms, and aquatic macroinvertebrates. TRGT will use this information to understand how we impact our water supply and the important role we play in water conservation.
Collected data is submitted to Georgia-Adopt-A-Stream and can be viewed here.
Temperature affects the feeding, respiratory, and metabolic activity of aquatic organisms. Stream temperature is often altered by anthropogenic influences such as increased temperatures from road and roof runoff, which can subsequently alter species composition in our waters. Temperature also controls the solubility of oxygen into water. High temperatures correlate to lower dissolved oxygen concentrations, making it harder for species with gills to breathe.
Dissolved oxygen (D.O.) is measured as percent saturation and concentration (mg/L). Aquatic organisms require certain concentrations of D.O. in the water just like we require a certain concentration in the air. Dissolved oxygen is naturally limited by temperature, photosynthesis, and microbial decomposition; however, pollution also limits D.O. directly or indirectly, by altering temperature and primary production.
Escherichia coli (E.coli) is a coliform bacteria specific to humans and other warm-blooded animal fecal waste. Thus, it is commonly used to detect pathogenic (disease-causing) conditions in a waterway. Our sampling results are compared to the U.S. Environmental Protection Agency’s E. coli standards for recreational use. This way, we can determine if fecal pollution is a problem in the Tennessee River Gorge.
Too low or high pH is detrimental to aquatic organisms. Most require a pH range of 6.8 – 8.2. Deviation from this range alters the solubility of important nutrients as well as toxic heavy metals, which can threaten the reproductive success of aquatic organisms. Human-induced pollution is a common cause of changes in stream pH such as hypereutrophication, acid mine drainage, and illegal dumping.
Aquatic macroinvertebrates, such as insects and crayfish, are indicators of stream quality because they are affected by the physical, chemical, biological, and morphological conditions of a steam. Understanding our watershed’s macroinvertebrate population will provide valuable information that will help us make land management decisions and track environmental quality over time. We collect macroinvertebrate samples every 3 months. Trained staff and volunteers identify macroinvertebrates in the field and then release the organisms back into the stream.
Mariah Prescott, Lead Water Quality Monitor
Mariah is an ISA Certified Arborist and holds a Bachelor's degree in Environmental Science from Michigan State University. She fell in love with the great outdoors while exploring the rugged mountains, slot canyons, and rivers around Flagstaff, Arizona where she lived for 8 years. Mariah, her husband Greg, and their giant dog Frankie settled in Chattanooga in 2011, and can't imagine living anywhere else.