Pattagansett Lake is a 128-acre lake in East Lyme, CT. Residential development and road surround much of the shoreline. There is a public boat ramp on the southern portion of the lake and an RV campground on the southeast peninsula. At the northern end of the lake is Camp Pattagansett, which is a camp for Girl Scouts that has a beach and swim area. The lake is a bass management area and has fishing tournaments at the state launch. Regular crew practices by the East Lyme High School are also held on the lake throughout the week.

The 2013 vegetative survey of Pattagansett Lake was a resurvey from 2006. The 2013 survey found 32 plant species compared to 25 species in 2006. Similar to 2006, the only invasive found was variable-leaf watermilfoil (Myriophyllum heterophyllum). The dominant vegetation was Robbins' pondweed (Potamogeton robbinsii), variable-leaf watermilfoil, humped bladderwort (Utricularia gibba), and purple bladderwort (Utricularia purpurea).

Variable-Leaf watermilfoil increased in abundance, from several patches in 2006 to one large continuous patch around the lake. The plant was found growing in up to 4 m of water and covers the entire southern portion, northwest arm, and southeast cove. Variable-Leaf watermilfoil was present on 60% of the transect points, compared to 27% in 2006.

Similarly, Robbins' pondweed expanded since 2006 and grows continuously all around the lake in up to 4 meters of water, including the entire southern portion. Robbins' pondweed was present on 47% of the transect points.

Since the 2006 survey, humped bladderwort and purple bladderwort increased in abundance from small to large patches around the entire lake. Humped bladderwort was present on 58% of the transect points compared to 40% in 2006, and purple bladderwort was present on 28% of the points compared to 19% in 2006.

The northwest arm and southernmost portion of the lake are difficult to navigate as they are extremely shallow (less than 1 m of water) and have become filled with plants and floating mounds of sediment causing eutrophication. White water lily (Nymphaea odorata), watershield (Brasenia schreberi), yellow water lily (Nuphar variegata), Robbins' pondweed, variable-leaf watermilfoil, humped bladderwort, and purple bladderwort are the main plants that dominate these areas. A narrow channel appears to have been raked down the center of both locations so that the residents there may still use their boats to access the rest of the lake.

Other Pattagansett Lake Surveys: 2006