Upper Saranac Lake Plant Monitoring Report
Adirondack Watershed Institute
Daniel Kelting & Corey Laxson
Summer 2013 marked the 10th anniversary of the independent long term monitoring study being conducted by the Adirondack Watershed Institute of Paul Smith’s College with funding from the Upper Saranac Foundation. The objectives of this independent study are to assess the manual control effort and to measure the effectiveness of control (e.g. duration, methods, native plant response). Details of the methods used to meet these objectives are found in the Research Approach section of this report. The results of this study show:
Milfoil density increased from 2008 to 2010 indicating the milfoil population was starting to rebound at the 15 monitoring sites and thus maintenance management was not able to hold the population at a sustained low level in those years
Milfoil density declined after 2010, with 2013 being the lowest densities measured since the transects were installed in 2004
Milfoil density was variable among the sites, with South Gull Bay and Little Square Bay responsible for the majority of density in 2013, while nine sites had no milfoil present in 2013
The persistently higher density sites such as Gilpin, North and South Gull, and Little Square Bays were highly variable year to year during the maintenance period, which makes controlling the milfoil at these sites more challenging
Milfoil density at the non-managed site in Fish Creek Ponds tripled in the last four years and was similar to the densities measured in Upper Saranac Lake in 2004, with the data suggesting that the population is in the beginning of exponential growth characteristic of invasive species after they have become established
Twenty species of aquatic plants were observed in 2013 with milfoil ranking 19th in terms of relative abundance
In addition to reporting the annual results, we conducted a statistical assessment of the accuracy and reliability of the program. This assessment answered two questions: 1) does the monitoring network accurately reflect the hand harvesting effort and 2) can the monitoring program reliably detect year-to-year differences in milfoil density? Our analysis showed that the answer to both of these questions was ‘yes’. This finding was based on an analysis that showed a strong positive correlation between density and removals (‘yes’ for question #1) and another that showed the sample size (i.e. 15 sites measured 4 times per summer) was adequate to detect year-to-year differences in milfoil density (‘yes’ for question #2). In fact, based on this analysis we believe the number of sampling events could be reduced from four (currently June, July, August, September) to three (propose July, August, September) per year without compromising the study objectives.
