Upper Guilford Lake, Guilford - 2023

Aquatic Plant Survey Map

Transect Data | Water Data

      Upper Guilford Lake is a 13-acre lake located in Guilford, CT. Boat access is carry-in only and no motors are allowed. There are a few residential homes lining its south-east side, otherwise it is surrounded by forest. Upper Guilford Lake was previously surveyed by the Connecticut Agricultural Experiment Station (CAES) in 2008.

      The CAES Office of Aquatic Invasive Species resurveyed Upper Guilford Lake on August 3, 2023. Fifteen aquatic plant species and two wetland plant species were found. This compares to 19 species in 2008. No invasive/non-native aquatic species were present in either survey. Cattail and phragmites (both wetland plants) species were present in the southern area of the lake close to the residential homes. Phragmites is an invasive species while cattail is native. Like 2008, watershield and white water lily were the most abundant species, followed by yellow water lily. The lilies made it difficult to thoroughly survey the northern coves of the lake. Pickerelweed inhabited the shoreline and was the next most abundant species. It had spread considerably from 2008. The other aquatic plants were found occasionally in the southern half of the lake. Substantially less purple bladderwort was present in 2023 compared with 2008.  Bur-reed was found in 2023 but not in 2008 while flat-leaf bladderwort, low watermilfoil, marsh primrose-willow, unidentified sedge, and slender naiad were found in 2008, but not in 2023.