The Lake Colby milfoil eradication project is one of the earliest and most important demonstration projects for non-chemical control of Eurasian Watermilfoil in the Adirondack Park.
Lake Colby is a strategic resource that is home to the D.E.C. Environmental Education Camp, the Town of Harrietstown’s Latour Park, the Village of Saranac Lake’s only public swimming facility, several public camp sites, and a DEC boat launch. The Lake hosts only seven private shoreowners, four of whom use the lake for drinking water, the rest of the Lake (16,000 out of 17,500 feet of shoreline) being either public-use or forever wild lands.
Due to the low private ownership on the Lake, finding funds for the project to-date has been an ongoing effort. Thanks to support from shoreowners, the Town of Harrietstown, the Village of Saranac Lake, and the Lake Champlain Basin Program, funds provided through grants from 2002 to 2006 were sufficient to make slow but steady progress, but were insufficient to deliver a final knockout punch to the spreading milfoil. In 2006 the LCA’s first NYS Invasive Species Eradication Grant allowed the first complete harvesting of the lake. Other lakes with sufficient financial resources to do multi-pass harvesting have demonstrated that Eurasian Watermilfoil can be brought under complete control within two to three years if (and only if) consecutive multi-pass harvests are conducted each season, eliminating in-season re-growth and seeding.
The LCA is again applying for a Lake Champlain Basin Program Grant for the 2010 season. We are again submitting the 18 letters of support we have received for our program from the village, town, Watershed Institute, Adirondack Medical Center, Historic Saranac Lake, and others in support of our request which is crucial to our continuing the program.
Harvests from 2002 through 2005 removed over 20 wet tons of milfoil in single-pass harvests, but each subsequent season found significant re-growth. In 2006 diver productivity was more than doubled through the use of a floating compressor system (known colloquially as a “hookah” or SNUBA rig). This increased productivity was applied in two full passes of the lake, removing more wet tonnage than in the prior four years combined.
From 2007 we extended this multi-pass approach to five full passes. The chart below shows results for the dozen years that we have been running this program. A bag of wetmilfoil, the y-axis, weighs approximately 25 pounds. The 2013 Watershed Institute Report is attached.
In addition the 55 existing benthic barriers have been re-set on high-growth areas. 43 of these are 20' x 20' mats and 12 are 12' x 12' mats. They are re-set twice a year by our dive team.
In 2013 hand harvesting again resulted in a reduced yield (which is good!). Unfortunately, chloride levels remain high in the lake (see Water Quality) and Recent studies show that road salt damages native plants but ironically Eurasian Watermilfoil thrives in high-chloride solutions, including the brackish waters of the Chesapeake area and in Florida.
The Paul Smith’s Watershed Institute has been the primary subcontractor for dive related activities, supplying a dive leader, divers, and surface support. Volunteers have provided additional surface support, some dive support, milfoil disposal (in an APA-specified composting bin), and materials (e.g., support watercraft). A five-person professional team (four divers and one surface person) subcontracted from the Paul Smith’s Watershed Institute costs about $1,800 per day. Thus far, this cost has been over 90% supported by grants and local government support.