Northern New York Invasive Aquatic Plant Survey Sylvia Lake by Frances McNierney, St. Lawrence University, 2012.

Methods: Surveys were conducted by paddling around the perimeter of the lake, including islands and bays, visually looking for plant beds. Rake tosses were used to get a sample of the plant(s) in the beds and these were then identified as an invasive species or determined to be native and returned. Samples of the invasive species were brought back to the lab for identification confirmation. A GPS was used to mark where the bed was located and the depth, substrate and size of the bed were also recorded. This information was then compiled into the map below.

Results: Invasive Species Found: Curly Leaf Pondweed (Potamogeton crispus) and Milfoil.
Further surveying would need to be done to determine if the Milfoil found in this lake was Eurasian or Variable Milfoil. However both of these species are invasive and because they both spread through fragmentation and have similar growth patterns they should be treated in the same manner.

Recommendations: Since Sylvia Lake has had Milfoil for so long the population around the lake is very knowledgeable and active in working to remove and control the population, which has proved to be quite successful. The benthic mats that are currently being used to treat the Milfoil seem to be effective at keeping the growth under control despite the fact that the species has been established in the lake for around eight years. Although they are expensive, when placed over existing plant growths these mats prevent the plants from getting sunlight, killing them completely in four to six weeks1.

In other areas “weed winders”, long poles with many spikes clustered at one end, are useful for pulling up plants that are growing alone while minimizing the risk of breaking off fragments. In terms of the Curly Leaf Pondweed since it does not spread by fragmentation, like the Milfoil, instead spreading by over wintering buds, I would recommend hand pulling it when it is spotted in the hopes of getting it before it is able to reach maturity and produce these buds2.

Since Sylvia lake has two known invasive species present already future focus should be on maintain this populations at levels at which they have a minimal negative effect on the ecosystem and preventing these species from spreading to other water bodies. One way that spreading prevention efforts could be improved might be with a sign in addition to the one currently at the boat launch encouraging boaters not to bring plant fragments on their equipment, listing the species that are in the lake with a picture of them to draw special awareness to the real risk that is presented by moving fragments from one water body to another.
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1 Maine’s Invasive Aquatic Species Program 2010 Summary, http://www.mainevlmp.org/wp/? page_id=183#BenthicBarriers (2010).
2 Curly-Leaf Pondweed (Potamogeton crispus), http://dnr.wi.gov/invasives/fact/ curlyleaf_pondweed.htm (January 2012).