Sewanee Field Adventure Part 7: Slippery Swimming Salamanders
Today the group visited a creek on the campus to do some water quality and riparian habitat analysis. We looked at various qualitative features of the stream like the surrounding shade-providing vegetation essential to fishes, the erosion of the banks, the turbidity of the water, the shape of my pair’s 45-foot section and the speed of the water as well as took measurements of quantitative properties such as dissolved oxygen, pH, total dissolved solids, conductivity and temperature. We also looked for salamanders under the rocks in the streams as they serve as indicators of the stream’s well-being. We were lucky enough to find seven or eight salamanders, one of which I found. They were all in the larval stage, meaning they had gills growing on the sides of their heads. We saw two new species, the Southern Two-lined Salamander and the Red Salamander, both of which are lifers for me! We then took some samples from the stream as well as the dammed up reservoir from which Sewanee residents get their drinking water to test how the iron concentration differs in distinct parts of the stream. We mixed the water from the samples with a chemical called ferrozine as well as a buffer solution, causing a chemical reaction that yielded a violet solution. We then put this solution in a cuvette (small rectangular prism used in color analysis) and placed the cuvette in a spectrophotometer that measured the absorptivity of the solution at a wavelength of 562 nm. Once the set width of the cuvette and the molar absorptivity constant for the solution were accounted for, the absorptivity was directly related to the molarity of the solution. Apparently, iron leaks out of the hematite minerals in the passage from the reservoir through the manmade earthen dam to the stream. While I enjoyed re-igniting my chemical interests in the lab, I thought finding and observing the tiny salamanders in the stream was the best part of my day!
Amphibians (2 species, 2 lifers):
Dragonflies (1 species, 1 lifer):
Butterflies (1 species, 1 lifer):
Fungi (1 species, 1 lifer):