Paul Smith’s College Adirondack Watershed Institute (AWI) recently presented new research detailing the threat of aquatic invasive species in Adirondack lakes at the Northeast Aquatic Plant Management Society meeting in Lake Placid, N.Y. The New York State Department of Environmental Conservation’s Invasive Species Management Grant Program funded AWI to undertake two studies.

The first study was presented by Dr. Michale Glennon, science director at AWI, and focuses on identifying and predicting which lakes are most vulnerable to the introduction and establishment of aquatic invasive species (AIS). Glennon’s research looks at which lakes experience the highest level of boater traffic and which lakes have ecological conditions that favor the successful establishment and spread of invasive species.

Glennon found that the motorboat traffic in the Adirondacks is highest at lakes that are large, are located in close proximity to interstates, and that have abundant amenities such as parking, marinas, boat rentals, and campgrounds. Because motorboats are the predominant vector for the transport of aquatic invasive organisms, and because these lakes have highest levels of traffic, they are likely to have the highest potential for arrivals of non-native species at launch points.

Glennon found that in addition to the level of boating activity on a lake, major physical and ecological drivers contributing to the establishment of AIS in lakes include the richness of the native aquatic plant community and connections to upstream invaded waters. The study has thus far examined Eurasian watermilfoil and variable leaf milfoil, two of the most prevalent AIS in the region.

“Understanding the patterns of boater traffic and which lakes are most vulnerable to the threat of aquatic invasive species will help the state and partners prioritize where to invest funding and staff to help prevent further spread or new infestations of these organisms,” said Glennon.

The second study was presented by Dr. Dan Kelting, executive director of AWI, and examines risk of AIS in Adirondack lakes and how effective the boat steward program and the existing AIS Spread Prevention Law are at prompting boaters to clean, drain and dry boats to reduce this risk.

The NYS Spread Prevention Law states that boaters must take aquatic invasive species spread prevention measures before launching and/or retrieving a boat in public waterbodies in New York. The law expired in June 2019 and is currently up for NYS reauthorization in June 2020. Clean, drain, dry is a nationally recognized term for inspecting and cleaning boats and fishing gear to prevent the spread of AIS.

Focused in the Adirondacks, the study found that 78 percent of boats have either been out of the water for at least two weeks prior to launching or had only visited the same waterbody in which they were launching. “These data show that the majority of boats launching in Adirondack waters are at low risk of transporting AIS,” said Kelting. “These boats are always in the same waterbody or are used infrequently.”

Only a minority of the remaining boats pose a potential risk of transporting non-native invasive species into the Adirondacks. These include, 12 percent of the boaters launching from another Adirondack lake, 6 percent from a waterbody elsewhere in New York, and 4 percent traveling from a different state.

The study also found that of higher risk boats, nearly 80 percent of them have had an interaction with a boat steward. An encounter with a boat steward appears to greatly enhance the adoption of spread prevention measures according to Kelting. Boaters who have ever had a prior encounter with a boat steward are also less likely to have AIS present on their watercraft. The results of the study, however, are unclear on whether the AIS Spread Prevention Law has an impact on compliance with clean, drain, and dry measures.

“We have an opportunity to enhance and target our educational efforts to boaters who are at high risk of carrying AIS. Strengthening the presence of stewards at high-risk, unstaffed waterbodies will enhance the impact on preventing AIS”, said Kelting. “There is also opportunity to increase compliance with the AIS Spread Prevention Law through increased high-profile educational efforts.”

“It is clear from our research that Adirondack waters continue to be threatened with invasion from both within the Park and from elsewhere,” said Glennon. “We recommend that AIS spread prevention programs around New York continue to be enhanced so that effectiveness of boat steward and decontamination efforts further improve. We recognize great value in the collaborative efforts to management for AIS, and are deeply appreciative of all of the partners who are involved in combatting aquatic invasive species in the region including the Adirondack Park Invasive Plant Program, The Nature Conservancy, Lake Champlain Basin Program, Lake George Park Commission, the Adirondack Park Agency, the NYSDEC and the many towns and lake associations. The combined steward training, standardization of methods, data sharing, and broad communication among these groups are tremendous strengths and provide a model for coordination in other regions.”

The mission of the Paul Smith’s College Adirondack Watershed Protect is to protect clean water, conserve habitat, and support the health and well-being of people in the Adirondacks through science, collaboration, and real-world experiences for students.