Green Pond, Sherman - 2024

2024 Aquatic Plant Survey of Green Pond

Transect Data | Water Data

Green Pond is a 30-acre waterbody located in Sherman, CT. It is a private pond managed by the Green Pond Ecological Society. Its maximum depth is approximately 35 feet.  

CAES OAIS performed its first survey of Green Pond in August 2022. Invasive Eurasian watermilfoil (Myriophyllum spicatum) was found frequently around the lake and has been actively managed since 2014 using diver-harvesting and benthic barriers. Many of these barriers appeared to have been installed prior to our survey. This has allowed sediment to gather on the barrier and vegetative growth to begin. CAES OAIS has demonstrated the barriers can be installed and removed in as little a month for season long control. We suggest that the barriers be placed in one spot for no more than one season.   

Minor naiad (Najas minor) was the other invasive species found in the lake in 2022. It was found by the beach in the north end and in a few locations along the western side of the pond. Minor naiad is an annual plant that regrows each year from the previous year’s seed. Thus, it is not noticeable until early to mid-summer when it grows in patches in the shallows. It often is most abundant in and around beaches. CAES OAIS is not aware of any control practices performed on this plant in Connecticut apparently because it is not a nuisance. If management in beach areas is desired, it can easily be removed with a rake.  In 2023, the herbicide ProcellaCOR was applied to control Eurasian watermilfoil.

During the CAES OAIS 2024 survey of Green Pond, vegetation occurred frequently throughout the lake and was present throughout the entire littoral zone. The littoral zone for Green Pond is deeper than other waterbodies in Connecticut because of is above average transparency (Secchi depth = 21 feet).  Compared to the 2022 survey, there were fewer species found (16 overall in 2024 compared to 18 in 2022); however, the vegetation was denser in 2024.

No invasive Eurasian watermilfoil was found in 2024, suggesting the ProcellaCOR® treatment was effective. Invasive minor naiad was still present, but only in a few sparse locations. The most commonly found species were native pickerelweed (Pontederia cordata), large-leaf pondweed (Potamogeton amplifolius), eelgrass (Vallisneria americana), white water lily (Nymphaea odorata) and yellow water lily (Nuphar variegata). Large-leaf pondweed and white-water lily occupied much of the shoreline and appeared in greater abundance than in 2022. It is possible large-leaf pondweed density increased due to the lack of Eurasian watermilfoil. The species found in 2024 for the first time were primrose-willow (Ludwigia species) and snailseed pondweed (Potamogeton bicupulatus). Notably, white water crowfoot (Ranunculus longistrosis) was not found in 2024. This plant occurs very sparsely throughout the lake and could have been missed during surveying.

Other Green Pond Surveys: 2022