Back Pond’s monthly fluorescence, oxygen, and temperature profiles. Chlorophyll concentration (green line), dissolved oxygen concentration (blue line), and temperature data (red line) were collected at every meter from the surface to the bottom from May through September.
Throughout the season, algae concentrations tended to be lower above the thermocline than they were below the thermocline. While fluorescence readings were highest in September, each month saw a small fluorescence peak, often below the thermocline. These higher readings were fairly deep, between 4 and 8 meters, making them below the portion of the water column that people usually use. Elevated readings also tended to be below the thermocline meaning that these readings are not represented in the chlorophyll samples analyzed in the Water Quality figure above. June and July’s high readings near the bottom were likely caused by sediment interference.
Gloeotrichia echinulata (a type of cyanobacteria (blue-green algae) commonly found in low-nutrient waters) can be seen with the naked eye. Gloeo density is reported as a value ranging from 0 – 6, based on the number of Gloeo colonies seen through a Secchi scope. Higher values indicate more Gloeo colonies. Gloeotrichia echenulata colonies were not observed in Back Pond in 2024.
