Fence Rock Lake, Guilford - 2011 
Fence Rock

2011 Aquatic Plant Survey of Fence Rock Lake 

Transect Data | Water Data

CAES IAPP surveyed Fence Rock Lake for the third consecutive year in 2011 in order to document the progress of the rarely found invasive Brazilian waterweed (Egeria densa). In 2009, Brazilian waterweed was initially found primarily in the western cove. By 2011, it had spread along the perimeter of the entire lake in small patches, and the patch in the western cove had expanded. Brazilian waterweed was the only invasive aquatic plant among the 18 species found in the lake during our survey. Brazilian waterweed was the most common plant in the lake. The most species rich area was the northeastern shore where 12 species were found: white water lily (Nymphaea odorata), quillwort (Isoetes species), watershield (Brasenia schreberi), Brazilian waterweed, waterwort (Elatine species), thread-leaf naiad (Najas gracillima), snailseed pondweed (Potamogeton bicupulatus), pickerelweed (Pontederia cordata), humped bladderwort (Utricularia gibba), low watermilfoil (Myriophyllum humile), spikerush (Eleocharis species), and yellow water lily (Nuphar variegata).     

The yearly expansion of Brazilian waterweed is troubling. The plant not only does it poses a threat to Fence Rock Lake but also to nearby lakes where it could spread. This lake is a prime example of a waterbody that could benefit from "early detection and rapid response" protocols.

Species recorded in our 2011 survey of Fence Rock Lake.
Scientific Names
*Invasive Species
Arrowhead Leafy pondweed Slender naiad Watershield
Brazilian waterweed* Low watermilfoil Snailseed pondweed Waterwort
Cattail Marsh primrose-willow Spikerush White water lily
Coontail Pickerelweed Thread-leaf naiad Yellow water lily
Humped bladderwort Quillwort Water starwort

Other Fence Rock Surveys: 2021, 2019, 2017, 20162013201220102009