Monitoring and sampling
Monitoring and Sampling
Since 2001, TWCWC and TLPOA have been collecting water quality samples from Twin Lakes to monitor the water quality and follow long term trends. Overall, the water quality trends for Twin Lakes have generally been consistent and point towards two healthy lakes.
The following section provides a summary of 2024 efforts and recent previous PLEON reports are linked below.
PLEON 2024 Report
For 2024, we again teamed up with Pocono Lake Ecological Observatory Network (PLEON) to continue these efforts with sampling conducted in June, July, and August. Our volunteers measure clarity, temperature, dissolved oxygen, pH, and conductivity (generally a measure of inorganic dissolved solids, such as chloride, nitrate, etc.) every meter from the surface to the bottom of each lake at the deepest point. Clarity is measured using a Secchi Disk, which is a black and white disk that is lowered into the water to measure how deep an observer can see. Samples are also collected at the surface, the middle, and the bottom of the water column and sent for laboratory analyses to determine the concentrations of nutrients (nitrogen, phosphorous), organic carbon, and chlorophyll. In addition, we collect samples of zooplankton and phytoplankton, which are the animal- and plant-like organisms, respectively, that make up the base of the food web. Studying these helps us gain a better understanding of the overall dynamics of lake quality. To read the full report click here. A high-level summary is provided below
While the full report presents data specifically for 2024, summary graphs that show trends over time provide the best insight into the state of our lakes:
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Temperature
Overall, the temperature of the lakes is relatively consistent over the years with a slight regional increase, as would be expected with rising global temperatures.
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Clarity
The depth to where the Secchi disk is observed is shallower over time, as the lakes become less clear. This aligns with regional observations, where lake clarity decreases as the negative effects of acid rain diminish over time.
Chlorophyll, nitrogen and phosphorus
Overall, the amount of chlorophyll, nitrogen, and phosphorus levels have all decreased in the Big and Little Lakes at a constant rate. This represents a general decrease in nutrients in the lake and likely can be attributed to our long term focus on implementing best practices to decrease the amount of septic, fertilizer, and other inputs around the lakes. However, ongoing vigilance is the only approach to making sure that we can keep this trend going in the right direction.
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chlorophyll
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nitrogen
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phosphorus
