Long Pond is sampled by LEA once per year in August. The long-term average reflects data from 1997 to 2023. The Secchi disk reading for 2023 was 5.0 meters, which falls into the moderate clarity range. The Secchi disk did not hit bottom this year but has in years past, indicating that Secchi depth may not be a reliable indicator of historical water clarity, however, the clarity trend is still reported because the majority of Secchi measures did not hit bottom. The total phosphorus reading of 9.4 ppb falls into the moderate range. The chlorophyll-a reading of 2.1 ppb falls into the moderate range. Long-term trend analysis indicates chlorophyll-a concentrations in Long Pond are stable and total phosphorus concentrations are stable, while clarity trend is decreasing. Gloeotrichia echenulata colonies were not observed in Long Pond in 2023.
Long 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 2023’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 Long Pond in 2023.
