Results of Lake Williams survey conducted by the Connecticut Agricultural Experiment Station in 2009


     In 2002, scientists at the Connecticut Agricultural Experiment Station (CAES) began surveying Connecticut lakes and ponds for invasive aquatic plants and investigating novel management options.  Surveillance focuses on both invasive and native vegetation to quantify the effects of invasive species on aquatic ecosystems. This research allows CAES to track the spread and record the arrival of invasive aquatic plants.  Surveys also provide baseline information to determine if the frequency and magnitude of invasions may be related to water chemistry, sediment type, boat launches, watershed development and climate change.  Management studies include tests on the effectiveness of herbicides, mechanical removal, water level manipulation, biological control, and integrated pest management.  This program is supported by the U.S. Department of Agriculture.

     In 2008, FLW requested that a survey of our lake be conducted.  CAES accepted that request and conducted the survey of Lake Williams in June of 2009.  Rachel Soufrine and Martha Balfour of CAES are seen analyzing their data in this photo taken on Lake Williams.

The results were subsequently published early in 2010.

Results of the Connecticut Agricultural Experiment Station survey of the lake follows:



1.  The below results are attributable only to CAES but for presentation on our web site, the text was re-written only to change the scientific names of the plants to the common names.  Additionally, the full table of Common vs. Scientific Names appears on the CAES web site but the below table is an excerpt of that table and contains only the plants referred to in the survey or on the CAES Survey Map of Lake Williams (a.k.a., Williams Pond).


The CAES Survey results follow:


      Our June, 2009 survey found 14 plant species of which only one, Variable-Leaf Watermilfoil (a.k.a.Various-Leaved Water Milfoil and Changeleaf Parrotfeather), is invasive. Variable-Leaf Watermilfoil mixed with Yellow Water Lily, White Water Lily (a.k.a. American Water Lily) and Watershield is abundant in the northern coves and within 30 meters (100 feet) of the shore.  Submerged vegetation also occurring in this area includes Spotted Pondweed (a.k.a. Heartleaf Pondweed), Common Bladderwort, Purple Bladderwort and Humped Bladderwort.


     In the southern half of the lake, Tapegrass (a.k.a., Eelgrass or Wild Celery) and Spotted Pondweed (a.k.a. Heartleaf Pondweed) is abundant along the shoreline. Snailweed Pondweed is found sparsely through the lake yet is slightly more common in the southern end and around the island. Also found sparsely around the islands includes Sevenangle Pipewort, Southern naiad (a.k.a. Southern Waternymph, and Spikerush).  Ribbon-leaf Pondweed was only found in the coves, to the left of the Lake Williams Campground swim area.


 Common Name

Scientific Name

common bladderwort

Utricularia macrorhiza (=U. vulgaris)

humped bladderwort

Utricularia gibba

marsh primrose-willow, marsh seedbox

Ludwigia palustris

purple bladderwort

Utricularia purpurea


Isoetes sp.

ribbon-leaf pondweed

Potamogeton epihydrus

Robbins pondweed

Potamogeton robbinsii

sevenangle pipewort

Eriocaulon aquaticum

snailseed pondweed

Potamogeton bicupulatus

southern naiad, southern waternymph

Najas guadalupensis


Eleocharis sp.

spotted pondweed, heartleaf pondweed

Potamogeton pulcher

tapegrass, eel grass, wild celery

Vallisneria americana

variable-leaf water milfoil, various-leaved water milfoil, changeleaf parrotfeather

Myriophyllum heterophyllum


Brasenia schreberi


Elatine sp.

white water lily, American water lily

Nymphaea odorata

yellow water lily

Nuphar variegata


The highlighted plants in the above table are shown in the map but are not discussed in the above survey results.


Click here to see the CAES Map in a separate tab or window.  The CAES map allows you to highlight various plants by eliminating the undesired plants from the view.


Click here to see the CAES water data in a separate tab or window.