LEA visits Perley Pond once a year in late August. This year’s clarity reading was deeper than the long-term average, while the total phosphorus concentration and chlorophyll concentration were below their long-term averages. The average deep-water phosphorus value was greater than 10 ppb above surface water phosphorus values, which suggests phosphorus recycling could be an issue. Long-term trend analysis indicates that total phosphorus concentrations are decreasing, while chlorophyll concentrations and clarity readings are stable. This year’s surface water temperature was cooler than last year’s surface water temperature. Oxygen depletion was observed in the lower half of the water column. Gloeotrichia echenulata colonies were not observed in 2024.
Perley Pond’s surface water chlorophyll (ppb), phosphorus (ppb), and Secchi depth (meters) data comparison. Colored areas represent the long-term range of values, from minimum to maximum. Area thickness indicates frequency of measurements at that value. Area thickness increases as more measurements are reported at that value. The vertical black line represents the long-term average value. The large red dot represents 2024’s average value.
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 Perley Pond in 2024.
