Grannis Lake, East Haven - 2004


2004 Aquatic Plant Survey Map of Grannis Lake

Transect Data | Water Data

Grannis Lake is located in East Haven between a road and a highly developed area with little to no plant buffer around the lake.  Grannis Lake is part of a Connecticut Agricultural Experiment Station study on the control of aquatic vegetation, which required more transects. 

The west side of this approximately 20-acre lake was dominated by sago pondweed (Stuckenia pectinata), which was in flower during a mid-July survey in 2004. The east side of the lake was dominated by the invasive curlyleaf pondweed (Potamogeton crispus), which was dying back and producing many turions. Both sago pondweed and curlyleaf pondweed were lush and reached the surface in as much as eight feet of water.

Shallow water near the shore of the small lake supported many plants of white water lily (Nymphaea odorata), which also occurred in occasional patches of yellow water lily (Nuphar variegata). Isolated plants of Eurasian watermilfoil (Myriophyllum spicatum) also were observed. Eurasian watermilfoil had been abundant the year before, when two herbicide treatments were administered. A patch of small pondweed (Potamogeton pusillus) was recorded in a cove to the northeast of a small island just off the northern shore.

Species recorded in our 2004 survey of Grannis Lake.
Scientific Names
*Invasive Species
Coontail Small pondweed
Curlyleaf pondweed* White water lily
Eurasian watermilfoil* Yellow water lily
Sago pondweed
Other Grannis Lake Surveys: 2011 Survey