Thank you!
Your support is sustaining the future of local news in our communities.

The hydrilla menace: 2025 marked a turning point

The hydrilla menace: 2025 marked a turning point

A boater prepares to launch from O’Hara’s Landing at East Twin Lake this past summer, near the area where hydrilla was first discovered in 2023.

By Debra Aleksinas

SALISBURY — After three years of mounting frustration, costly emergency responses and relentless community effort, 2025 closed with the first sustained signs that hydrilla — the aggressive, non-native aquatic plant that was discovered in East Twin Lake in the summer of 2023 — has been pushed back through a coordinated treatment program.

The Twin Lakes Association (TLA) and its coalition of local, state and federal scientific partners say a shift in strategy — including earlier, whole-bay treatments in 2025 paired with carefully calibrated, sustained herbicide applications — yielded results not seen since hydrilla was first identified in the lake.

The arc of the problem

The Connecticut River strain of hydrilla at East Twin Lake, first detected near O’Hara’s Landing Marina, is an unusually robust variant that quickly triggered emergency removals, diver searches and spot treatments, as TLA officials scrambled to contain fragments capable of rapidly sprouting into new beds.

By 2024, the cost of fighting the invader had grown significantly, straining both community and association budgets as managers moved from isolated spot treatments to serial applications and broader planning efforts. Monitoring and repeated partial treatments that year helped prevent larger outbreaks but failed to eliminate the plant.

“It became pretty clear that the Whack-a-Mole strategy wasn’t going to work,” said George Knoecklein of Northeast Aquatic Research, the TLA’s limnologist.

A strategic pivot in 2025

Drawing on lessons from earlier seasons, TLA leaders and limnologists adjusted their approach in 2025. Instead of reactive, site-by-site responses, the association began the season with a planned, sustained dosing of the northeast cove of East Twin Lake and the lake’s full littoral zone beginning in late May, maintaining low, permitted concentrations of the systemic herbicide fluoridone throughout the growing season.

Operationally the work involved close tracking of application tracks, repeated water sampling to confirm target concentrations, and diver-assisted surveys in deeper water to find any remaining pockets.

The payoff: hydrilla retreated in 2025

By mid-summer and into early August, field surveys and association updates reported a dramatic decline in visible hydrilla within the lake.

At the TLA’s annual August meeting, association leaders described the season as “the first good news we’ve had in three years,” while cautioning that the victory is fragile and requires continued monitoring and rapid response to any new fragments or regrowth.

At the annual meeting, it was announced that the final two planned applications of the herbicide Sonar would not be needed. The slow-release pellets currently in the water are expected to remain effective, reaching the target duration of 120 days.

TLA officials reported that East Twin Lake is closer than ever to achieving a functional eradication of the invasive plant infestations.

They emphasized, however, that this progress has been made possible through continued funding, permitting, and close coordination with state partners. The success of this effort could also provide valuable insights for addressing similar challenges in other lakes affected by the Connecticut River strain.

Why this year’s approach mattered

Several elements distinguished the 2025 season: an earlier start to herbicide applications, sustained low-level dosing, frequent monitoring, and data-driven coordination among the TLA, its limnologist, state and federal agencies, and contractors.

The payoff came at a price: three years of repeated interventions had driven lake management expenses sharply higher, and the 2025 season required continued fundraising and justification to town and state stakeholders.

The wider use of herbicides in waterways remains controversial in some quarters, and TLA officials stressed that the treatments used in East Twin were done under state permits with scientific oversight — and that results would be shared cautiously as case studies for other affected lakes.

What comes next

TLA and partners made clear the 2025 results are cause for cautious optimism, not celebration.

The next steps include diver-assisted surveys of deepwater areas to check for any surviving turions or isolated plants; continued low-level surveillance and rapid spot treatment to snuff out any reappearance and sharing methodologies, and monitoring data with neighboring lake groups and state programs to refine best practices for tackling the Connecticut River strain.

The lake association’s Fall newsletter reported that while treatment costs are expected to be moderate in 2026, “the heightened level of surveillance will continue.” The TLA predicted $400,000 will be spent on lake management next year.

By the end of 2025, what began as an emergency discovery in East Twin in 2023 had evolved into a test case for a new, more intentional treatment model. The TLA and its partners achieved the first season in which hydrilla substantially receded in the lake — a breakthrough that shows the combination of early action, sustained dosing and disciplined monitoring can work against this particularly aggressive strain.

That success, however, comes with an explicit rider: vigilance, funding and science-backed management must continue if the Twin Lakes are to remain hydrilla-free.

Latest News

Recovery underway after July 4 storms devastate Northwest Corner

Ben Blackwell directs traffic in Salisbury as motorists navigate road closures caused by fallen trees.

Patrick L. Sullivan

This is a developing story.

After a series of extreme storms pummeled the Northwest Corner late July 4, communities are picking up the pieces and offering support to those affected by blocked roads, downed power lines, and power and water outages.

Keep ReadingShow less
Storms rip through Northwest Corner on July 4, stranding travelers, closing roads and knocking out power

A blocked road on Route 41 in Salisbury looking north at Cobble Road.

Patrick L. Sullivan

Updated July 5, 10:00 a.m.

What began as a picture-perfect Independence Day took an abrupt turn Saturday evening, as powerful thunderstorms and possible microbursts swept across the Northwest Corner, bringing down trees and power lines, closing roads and leaving many residents unable to reach home.

Keep ReadingShow less
Kent's Fourth of July plans change due to heat, potential storms

The Veteran’s Memorial is set to receive a new plaque commemorating Kent’s 44 known Revolutionary War servicemen. The stone will be displayed throughout the weekend’s USA 250 celebrations.

Alec Linden

KENT – Kent organizers made last-minute changes to the town's Independence Day celebrations due to extreme heat and possible storms, bringing some activities inside and making slight changes to the parade. Fireworks at Lake Waramaug are planned as scheduled.

Members of the town’s USA 250 Subcommittee made the changes during a July 1 after the National Weather Service issued an extreme heat warning. With temperatures expected to reach the low to mid-90s, Gov. Ned Lamont also activated Connecticut's Extreme Hot Weather Protocol on Tuesday, which remains in effect through Sunday.

Keep ReadingShow less
google preferred source

Want more of our stories on Google? Click here to make us a Preferred Source.

E. Jean Carroll backs out of book-signing event at Hotchkiss Library for safety reasons

The Hotchkiss Library of Sharon will host its 28th annual Sharon Summer Book Signing event July 31 through Aug. 2.

Aly Morrissey

SHARON – Facing threats of violence amid a public dispute with President Donald J. Trump, famed author and journalist E. Jean Carroll is no longer expected to attend a highly anticipated book-signing at The Hotchkiss Library of Sharon, though library officials said they have not received formal notice that she has canceled.

The meet and greet was originally scheduled for Aug. 1 as part of the library’s Sharon Summer Book Signing event – which will take place as planned – but Library Director Gretchen Hachmeister said July 2 that Carroll’s attendance is no longer expected. She said the writer is allegedly in an undisclosed location under police protection after receiving death threats related to a recent Supreme Court decision and the president’s subsequent posts on social media.

Keep ReadingShow less

HVRHS Announces Senior Awards

HVRHS Announces Senior Awards

Senior awards for the HVRHS Class of 2026 have been announced.

Nathan Miller

The Housatonic Valley Regional High School senior awards were announced for the Class of 2026. The graduation ceremony was held Friday, June 19. Student speakers acknowledged the importance of community, as several reflected on overcoming significant adversity in their young lives.

Norma Lake Award - Shanaya Duprey

Keep ReadingShow less

The nature of Upstate Art Weekend

The nature of Upstate Art Weekend
Opening of Upstate Art Weekend at Olana with Helen Toomer, Ellen Harvey, Jean Shin and Gabriela Salazar
D.H. Callahan

On Thursday, June 25, a collection of eager art enthusiasts gathered at Olana State Historic Estate in Hudson to kick off the seventh annual Upstate Art Weekend (UAW).

Helen Toomer, founder, was joined by sculptors Ellen Harvey, Jean Shin and Gabriela Salazar to discuss their work and the legacy of painter Frederic Church. Church, whose 200th birthday is being celebrated this year, is widely credited as one of the founding members of the Hudson River School of painting. The discussion took place at Olana, Church’s grand estate, where the three artists’ installations are on view.

Keep ReadingShow less
google preferred source

Want more of our stories on Google? Click here to make us a Preferred Source.

google preferred source

Want more of our stories on Google? Click here to make us a Preferred Source.