Lake George Watershed Lake Steward Program End of Season ...

DRAFT
Plants/Organisms Found
Each vessel entering the lake was inspected for any plant material/organisms. Samples
were collected and then identified by either a Lake Steward or by Larry Eichler at the Darrin
Fresh Water Institute. Boats were also inspected leaving the lake when possible.
Plants/Organisms Going In
2%
% Native versus Invasive
N o
Y es
N ative
39%
Invas ive
61%
98%
Figure 12: Comparison of boats found
with and without plants/organisms.
Figure 13: Comparison of native vs. invasive
specimens found.
A total of 45 samples were collected from 31 boats entering Lake George at Norowal Marina
and 1 boat leaving. The 31 boats entering make up 2% of the total boats launching at
Norowal Marina during the thirteen weeks a Lake Steward was stationed there. Norowal
Marina’s 2% of boats entering with plants/organisms is the second highest among the
launches visited by Lake Stewards this summer. Some boats had more than one type of
plant on them, which resulted in more samples than the number of boats carrying the
samples. For instance, 1 boat entering had 3 different species of native plants found on
it, while another boat had both curly-leaf pondweed and Eurasian watermilfoil on it, both of
which are invasive aquatic plants. Zebra mussels were found on two different boats, 1 of
which had been in the Saratoga Lake earlier that same day.
Eurasian watermilfoil (Myriophyllum spicatum), zebra mussels (Dreissena polymorpha),
curly-leaf pondweed (Potomogeton crispus), and water chestnut (Trapa natans) were all
invasive species removed from boats about to enter Lake George. 28 of the 45 samples
were invasive, so more than half of the samples turned out to be invasive species prevented
from entering the lake (figure 13).
A wide variety of native plants
were found, including: slender-leaf
pondweed, flat-stem pondweed,
Vasey’s pondweed, coontail, water
marigold, narrow-leaf pondweed,
eel grass, duck celery, and a few
other types of native pondweeds
and waterweeds. Of the invasive
plants found, Eurasian watermilfoil
was the most common, followed by
curly-leaf pondweed (figure 14).
Number of Invasive Specimens Found
8
1
2
17
E uras ian W aterm ilfoil
W ater C hes tnut
C urly -leaf P ondw eed
Zebra M us s els
Figure 14: Summary of invasive species removed from boats.
28 Lake George Watershed Lake Steward Program End of Season Report 2008