Monthly fluorescence, oxygen, and temperature profiles for Long Lake’s main basin. 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.
Unlike most of the lakes in the area, algae concentrations tended to be higher above the thermocline. Fluorescence readings were highest in June and July. Most elevated readings were between 3 and 7 meters, making them below the portion of the water column that people usually use. Higher readings tended to be near or above the thermocline meaning that these readings are represented in the chlorophyll samples analyzed in the Water Quality figure above.
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. The middle basin’s Gloeotrichia echenulata colonies were observed beginning in early July this year with densities ranging from 1 – 3 on the Gloeo density scale.
