8984-R2_NewGloucester_2023-2024_AnnualReport_Web

2024 Sabbathday Lake Water Quality Report

in Sabbathday Lake in 2024 were largely made up of harmless non-bloom forming phytoplankton and at levels indicative of overall high-water quality in the lake.

2024 Phytoplankton Density Sabbathday Lake Station #1

1000 1200

0 200 400 600 800

Density (cells/mL)

07/10/24

08/14/24

09/11/24

Diatom Green Gold Cyano Dino Crypto Eugleno

Figure 7. Phytoplankton density for Sabbathday Lake, 2024.

2024 Phytoplankton Biomass Sabbathday Lake Station #1

0.0 100.0 200.0 300.0 400.0 500.0 600.0

Biomass (µg/L)

07/10/24

08/14/24

09/11/24

Diatom Green Gold Cyano Dino Crypto Eugleno

Figure 8. Phytoplankton biomass for Sabbathday Lake, 2024.

Gloeotrichia echinulata or “Gloeo” is a genus of planktonic freshwater cyanobacteria that forms tiny spheres that are visible to the naked eye floating in the water column. Gloeo grows at the sediment water interface and then rises through the water column to the surface waters where it completes its life cycle, dies, and sinks back down to the bottom of the lake where it will stay through the winter months until conditions are again suitable for growth (King & Laliberte, 2005). The presence of Gloeotrichia has been documented in Sabbathday Lake in the past but was not observed in 2023. In

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