‘A lot of unknowns’ surround hydrilla battle

SALISBURY — A rusty antique tractor with attached trailer blocked entry to the privately-owned boat launch at O’Hara’s Landing Marina on East Twin Lake early Tuesday morning, Sept. 19.

It was parked horizontally to keep boats from entering the lake for about three hours while a team of two aquatic specialists chemically treated areas around the marina where patches of an aggressive, non-native aquatic plant, hydrilla verticillata, are thriving.

Dave Haab, the marina’s business owner for the past 50 years, and Twin Lakes Association (TLA) board members Grant Bogle and Russ Conklin, were on site as Zach Davis and JD Hannon from The Pond and Lake Connection of Brookfield performed the herbicide treatment.

Nearby, ‘Whitey Bulger,’ the marina’s nicknamed white-plumed resident egret, kept its eye on the action. Native American lore has it that seeing an egret is a good omen for a hunt.

On this day, a hunt was on to seek and destroy patches of the robust Connecticut River variant of hydrilla, which poses a threat not only to the 830-acre East Twin Lake, also known as Washining Lake, but also to other bodies of water local and statewide.

The weapon of choice was a gas-engine, flat-bottom airboat driven forward by an obnoxiously loud, above-water propeller and outfitted with two rear nozzles attached to hoses which dispensed the herbicide ProcellaCOR at hydrilla hot spots via onboard GPS tracking. A hand-held spray gun, operated by Davis, was also used for spot treatments.

During the chemical application within a 4-acre area near the marina, the aquatic experts said they dispensed 259 PDU’s, or Pesticide Dispersal Units, of the milky white herbicide.

 “That’s equal to about six and a half gallons,” noted Davis. “We use a lower dose with invasive milfoil, but with hydrilla we have to bump up the dosage so it will probably impact a few other plants. Everyone is on board with eradicating this as quickly as possible.”

Gregory Bugbee, associate scientist with the Connecticut Agricultural Experiment Station (CAES) confirmed that “a pretty high” dosage of ProcellaCOR was recommended after “a lot of meetings on this” among the lake and environmental experts. 

“The bottom line is, there was a lot of effort put forth by the lake association,” and the treatment method decided upon was not taken lightly, said the CAES scientist.

East Twin was identified in late June as the first lake in Connecticut infected with the aggressive Connecticut River variant of hydrilla, and the strain has also since been found at Amos Lake in Preston, a 113-acre lake in the Thames River Drainage Basin, according to Bugbee, who described both discoveries as “heartbreaking.”

The CAES scientist reported on Thursday, Sept. 21, that the Amos Lake infestation was noticed during survey work. “It’s amazing that we found it,” said Bugbee, who believes that East Twin and now Lake Amos, are not the only lakes where the Connecticut River strain of hydrilla lurks.

“A lot of boats come from the Connecticut River and then go fish in another lake,” unaware that they may be spreading hydrilla fragments attached to their boats or trailers, said Bugbee.  

“We haven’t even scratched the surface of all the boat ramps around the state. We know it’s on the move, so it’s very concerning.”

“Is that a nice tall hydrilla right there?” asked Hannon from the driver’s seat of the airboat as he fired up the engine.

“There’s probably one right under the boat right now,” Davis responded while hopping onboard the watercraft as it slowly moved past moored boats and toward open water. 

“Oh yea, look at that beauty,” said Hannon, pointing to a patch of hydrilla just below the water’s surface, his voice drowned out by the roar from the propeller as the boat gained speed.

Earlier, Davis recalled a recent treatment on Lake Lillinonah, and between the loud noise emanating from the airboat’s above-water fan and the dense mist it had created, “someone thought the boat was on fire.”

Fast forward a few hours, and the team returned to shore, satisfied with the treatment. Hannon produced a single strand of dark, healthy hydrilla for observation.

“We are getting it treated at the right time,” just before October when the hydrilla would naturally die back and overwinter, noted Davis.

Globally, hydrilla is among the most noxious invasive aquatic plants because of its ability to adapt to a variety of environments and outcompete native vegetation. It also presents a double whammy: when it does die back and decompose, it sucks the oxygen out from the water.

“What we’re hoping,” said Bugbee, “is that because ProcellaCOR is a systemic product, it will be absorbed into the foliage, stem and roots and destroy the plant. But there are just so many unknowns here.”

He also noted that a stray patch of hydrilla, identified north of the marina, was not targeted for treatment last week because a state-listed protected native species, water marigold, grows in the area.

“That will be a problem that needs to be dealt with.”

Bogle, TLA’s president, said a scientific meeting has been set for Tuesday, Oct. 3 when TLA officials, along with representatives from its lake management company, the state Department of Energy and Environmental Protection (DEEP), the U.S. Army Corp of Engineers, the chief scientist at SePRO Corp., the manufacturer of the ProcellaCOR, and CAES’ Bugbee, among other officials, will gather to assess how well the treatment worked and management plans moving forward.

“We’ll know by then what happened, where we are with this and how we are going to fight this in the years ahead,” said Bogle.

CAES’ Bugbee said Twin Lakes is essentially a test case for similar infestations that will follow. “Up until this, we had not observed hydrilla in any lakes or ponds outside of the Connecticut River System.”  As for his initial prognosis, “Because this strain has never been treated” with ProcellaCOR, “there is an experimental component to this. We don’t necessarily know what will happen.”

DEEP steps up public awareness at boat launches

In response to growing concern about hydrilla’s rapid spread, the Connecticut Department of Energy and Environmental Protection (DEEP) plans to post new signage at boat launches where the non-native weed is present, urging boaters to inspect and clean their vessels after every use.

Signage is already in place at boat launches along the Connecticut River, which is being choked in places by hydrilla, according to Paul Copelman, DEEP’s media relations manager. 

 “We are in the process of getting new signs printed and posted at additional boat launches where hydrilla has been detected, including at Twin Lake,” Copelman confirmed in an email on Thursday, Sept. 21.

The signage recommends that before leaving the launch, boat owners clean all aquatic plants and other debris from boat and trailer and dispose of it properly and drain all water from boats.

DEEP also suggests that prior to the next launch, watercraft are allowed to dry for a minimum of one week in hot/dry weather or four weeks in cool/wet weather, or wash everything that had contact with the lake’s water with hot, high-pressure water, a salt solution, 100% vinegar or 10% bleach or detergent.

DEEP is also reminding boaters that it is illegal to transport on a boat or trailer any vegetation and aquatic invasive species, and that there is a $95 fine for each violation.

“Even those who are conscientious about cleaning can leave a fragment they didn’t see under a boat or under the open metal frame on a trailer,” noted Gregory Bugbee, associate scientist with the Connecticut Agricultural Experiment Station (CAES).

Bugbee noted that one of the issues with O’Hara’s Landing Marina on East Twin Lake is that it is a privately owned marina, not a public boat launch, and DEEP “doesn’t ordinarily go to the private launch sites” to erect signage, as landowner permission would be involved.

Dave Haab, who manages the O’Hara’s Landing Marina on East Twin Lake said he welcomes the posting of state signage at the private launch but hopes that boaters take notice, and action.

“It runs the gamut. Some people just don’t pay attention to that stuff. I think there are some people who care a lot about it, and others who don’t care at all. It’s all about them.”

Zach Davis hand-sprayed areas close to the shore of East Twin Lake where the invasive hydrilla was identified on Sept. 19. Photo by Debra A. Aleksinas