AWI stewards intercept hydrilla on personal watercraft trailer at Upper Saranac Lake

Aug 2, 2017 | News

On July 29, watercraft inspectors Dave Prosser and Bayle Reichert inspected a pair of personal watercrafts attempting to launch at the Saranac Inn State Boat Launch on Upper Saranac Lake, subsequently detecting and removing a strand of hydrilla (water thyme, or Hydrilla verticillata), a fast-growing invasive aquatic plant currently established in several New York lakes.

Hydrilla, commonly referred to as “Eurasian watermilfoil on steroids,” is being aggressively managed by the New York State Department of Environmental Conservation and partner organizations wherever it is found in New York. Since 2011, A multi-million dollar control effort has been underway on Cayuga Lake alone. Other states, such as Florida, can spend up to $30 million annually on hydrilla control. Once introduced, hydrilla can grow at startlingly fast rates – up to an inch per day – and forms floating mats that are so dense they block sunlight, allowing the invasive plants to outcompete native vegetation. These dense mats can also completely block recreational activities such as boating and swimming.

This is the first confirmed instance of hydrilla detected and removed in the history of the Adirondack Park’s aquatic invasive species prevention efforts. If introduced into the Adirondacks, hydrilla could have devastating ecological and economic impacts. An economic impact study commissioned by the Adirondack Park Invasive Plant Program (APIPP) estimates that if hydrilla were allowed to establish and spread throughout the Adirondacks, it could result in losses of $6.65-$9.5 million annually in direct visitor spending.

Hydrilla removed from the watercraft. Photo: Jake Sporn

Hydrilla removed from the watercraft. Photo: Jake Sporn

In the process of the watercraft inspection, Prosser found a small strand of dried aquatic vegetation draped over the rear beam of the trailer, near the trailer’s wheel well. When asked, the boat owner reported that he had used the watercraft last in Maryland’s Potomac River, where hydrilla is present. The inspectors initially thought the organism was native elodea, but further examination at Paul Smith’s College’s Adirondack Watershed Institute confirmed the approximately twelve-inch strand was hydrilla.

Stewards perform routine courtesy boat and trailer inspections to ensure the hull, engine, anchor, and all compartments and equipment are clean, drained, and dried to prevent the spread of aquatic invasive plants and animals. The two personal watercrafts were each carrying a green plastic seal from the Lake George Park Commission, indicating they had recently passed an invasive species inspection. The owners stated that they had stopped at the Lake George Park Commission inspection station near the Northway and requested an inspection. The LGPC inspectors found no materials and gave the boats a green seal. When the watercraft arrived at Upper Saranac Lake, the strand of dried hydrilla was visible to the inspectors.

“This close call reinforces the need for the program and demonstrates the risks of exposure that Adirondack waterways face from distant AIS infestations,” said Eric Holmlund, director of the Adirondack Watershed Institute Stewardship Program. “This event shows the importance of having multiple points of contact and inspection, whenever possible, for watercraft entering our region. Each element of the prevention network reinforces every other element. I think it’s clear that we need each other.”

The Saranac Inn boat launch inspection station is one of 60 locations where watercraft stewards perform boat inspections across the region as part of the NYSDEC-funded Adirondack AIS Prevention Program. The Saranac Inn watercraft inspection station is funded by a partnership including New York State, the Upper Saranac Foundation, The Cloudsplitter Foundation, and the Lake Champlain Basin Program. The Adirondack Region AIS Prevention Program also provides 16 decontamination stations for those boats failing to arrive clean, drained, and dry. The public can learn about the free network of AIS spread prevention locations and resources at

“Once again we are reminded of how vulnerable Adirondack lakes are to the introduction and spread of aquatic invasive species from beyond New York,” said Brendan Quirion, manager of APIPP. “Hydrilla is a force to be reckoned with unlike anything Adirondack waters have ever experienced. Vigilance and multiple levels of spread prevention interaction with boaters provide our strongest defense and deserve all the credit for this successful interception.”

A body of water clogged with hydrilla.

Hydrilla in Cayuga Lake Inlet. Photo: Bob Johnson, Racine-Johnson Aquatic Ecologists

Guy Middleton, Upper Saranac Foundation’s Lake manager, praised the watershed stewards.

“For many visitors, meeting watershed stewards at the boat launches may be the first interaction they have had regarding invasive species education, but for our lake, the stewards are the last line of defense protecting our watershed,” he said.

“While we have conducted more than 11,000 boat inspections and almost 1,000 decontaminations at Lake George this year, finding dozens of boats with invasive species on them, it can be difficult to get 100 percent all the time,” said Dave Wick, executive director of the Lake George Park Commission. “While this plant material evaded our inspectors, we are thrilled that it was caught by the stewards up north. There is great merit in having multiple sets of eyes out there in the region to keep our waterbodies safe. We will redouble our efforts in Lake George to ensure that our line of defense against new invasives is as strong as it can be.”

“Stewards remain the most important component of a regional response to address aquatic invasive species spread on recreational watercraft,” added Meg Modley, aquatic invasive species management coordinator at the Lake Champlain Basin Program. “The inspectors’ interception of hydrilla reinforces the need for boaters to clean, drain, and dry their watercraft and equipment. Hydrilla is a very real threat to our lakes in the Northeast and this is an invaluable save.”

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