Aquatic Invasive Species

Primary funding for our Aquatic Invasive Species Prevention programs is provided by our Membership Fund. Become a member today!

The Concern:

Aquatic invasive species (AIS) are non-native plants, animals, and other organisms that have evolved to live primarily in water (aquatic habitats) rather than on land (terrestrial habitats). Some of these species can harm the environment, economy, and/or human health. Once AIS finds their way into a waterbody, they are virtually impossible to eliminate and extremely expensive to manage. If current populations of AIS go unchecked and new species are introduced, the negative impacts on Skaneateles Lake will increase dramatically.

Known AIS in Skaneateles Lake include:

  • Eurasian watermilfoil
  • Curly-leaf pondweed
  • Scuds
  • Starry stonewort
  • Viral hemorrhagic septicemia
  • Zebra and Quagga mussels




Over 180 other AIS can be found in the Great Lakes just 40 miles away, and new AIS have made their way into neighboring finger lakes. For example, Cayuga Lake is managing the overwhelming and costly impact of hydrilla—an aggressive aquatic plant. As of 2020, Cayuga Lake’s costs to manage Hydrilla exceeded $3M, with annual operations / maintenance costs over $350,000.

So far, Skaneateles Lake has remained clear of hydrilla, but if it finds its way here and adds to the existing milfoil and pondweed “biomass,” an increase in water turbidity and phosphorus release might occur, contributing to increased HAB activity.

Our Programs:

Milfoil Control:

The 2023 Milfoil Report

In 2007, SLA created a Milfoil Control program that has reduced the species’ coverage on Skaneateles Lake to a level now requiring “maintenance” control. The SLA Milfoil Control program consists of a lake survey each fall to locate and document large growth patches of milfoil, and then the following spring those patches are covered with benthic mats constructed from geotextile material. Each mat is left on a milfoil patch for a minimum of 8 weeks to insure complete elimination, and then the mats are rotated. The Milfoil Control program costs ~$200K annually and is funded by SLA Memberships and other sources, including $30K in Finger Lakes-Lake Ontario Watershed Protection Alliance (FLLOWPA) funds administered by Onondaga County.

Read our 2023 Milfoil Report for results


Boat Launch Steward Program:

In August 2012, SLA instituted the Boat Launch Steward program to help combat AIS introduction to Skaneateles Lake. Boat Launch Stewards are hired, trained and positioned at the New York State DEC Boat Launch, the Skaneateles Town Boat Launch in Mandana and Andrew. R. Fuller Park Launch in Scott.

The stewards hired for the boating season are primarily students who receive training on invasive species found in Skaneateles Lake, and potential invaders from other water bodies. Their duties include asking permission to conduct a visual inspection of water crafts / trailers for any attached marine life, and then removing any vegetation that is found. The stewards record data on each inspection as part of the New York State Watercraft Inspection Steward Program Application (WISPA). The stewards also educate visitors on the value of launching a clean, drained, and dry boat.

2022 Results:

  • SLA boat stewards conducted 7,250 surveys, and inspected 8,046 water crafts
  • AIS was detected in 2.63% of surveys (191)
  • Boats coming to Skaneateles Lake come from Cayuga (most), Otisco, Owasco, and Oneida (least)