Working in the Watershed: Invasive species removal

Among the great blue herons and lily pads in the Town Farm Bay and LaPlatte River wetlands, volunteers spent June and July paddling around the wetlands to remove invasive European frogbit plants. This effort has been coordinated every year since 2009 by Lewis Creek Association (LCA), and is paid for by Town budget in Charlotte and Shelburne. Native to Europe and Northern Asia, European frogbit was brought to the United States via the St. Lawrence River, where it was first planted in arboretum ponds in Ottawa. It is considered an aquatic invasive species because it grows on the water surface and out-competes native plants for sunlight and nutrients.

When frogbit was discovered in Town Farm Bay in Charlotte, there was 50 percent cover throughout the wetland. With consistent seasonal management from volunteers, the frogbit cover has been reduced to and maintained at about 5 percent. In contrast, when frogbit was discovered in the LaPlatte wetlands it had a low percent cover, providing an opportunity for “early detection, rapid response”. Though the invasive plant will not be eradicated by Lewis Creek Association’s efforts in either location, maintaining this low population allows native plants and the critters that rely on them to thrive. This year, volunteers removed 1,670 pounds of frogbit from the 50-acre Town Farm Bay wetland complex, and 800 pounds of frogbit from the 77-acre LaPlatte River wetland complex. Because frogbit levels are consistently low, LCA and volunteers can now take on the management of other invasive species in the Bay. According to technical advisors for this program at Lake Champlain Basin Program, flowering rush should be the next priority. This year, volunteers mapped flowering rush and began removal, eliminating 20 pounds of the rush. Next year, it will be harvested in addition to frogbit with the same budget and resources.

The budget also includes the annual monitoring of the LaPlatte River, McCabe’s Brook, Thorp Brook, and Kimball Brook. The sampling season is still in progress and will last through October. Volunteers collect water samples which are then taken to the LaRosa lab, run by the Agency of Natural Resources, to analyze. This year, LCA is continuing to sample phosphorus, nitrogen, and total suspended solids during high flow events like heavy rain or snow melt in order to study nutrient loading to Lake Champlain. To see last year’s results, visit the LCA website at

Not only is this water quality stewardship program important for maintaining productive, functioning, and scenic waters – it also allows residents of Charlotte and Shelburne to become involved and be advocates for water quality. The most valuable way data can be shared is by passionate people you know in your community. This program being funded through the Town budget is crucial, since it allows the Town to take ownership in local water quality and natural resources that are so important to protect.