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

Roomful of Blues set for April 17 show at Infinity Hall in Norfolk
Photo provided

NORFOLK –Roomful of Blues, the Rhode Island-based band hailed by DownBeat magazine as being “in a class by themselves,” will bring its mix of blues, jump, swing, boogie-woogie and soul to Infinity Hall in Norfolk on Friday, April 17, at 8 p.m.

The long-running group, formed in 1967, is touring behind its Alligator Records album Steppin’ Out!, released in late 2025.

Keep ReadingShow less

Robert E. Stapf Sr.

Robert E. Stapf Sr.

MILLERTON — Robert E. Stapf Sr. (Bobbo), a devoted husband, loving father, grandfather, great grandfather, brother and friend to many, passed away peacefully on April 9, 2026, at the age of 77, happily at home surrounded by lots and lots of love and with the best care ever.

Bob was born Jan. 16, 1949, to the late Peter and Dorothy (Fountain) Stapf. He began working at an early age, met his forever love, Sandy, in 7th grade and later graduated from Pine Plains Central School.

Keep ReadingShow less

Michael Joseph Carabine

Michael Joseph Carabine

SHARON — Michael Joseph Carabine, 81, of Sharon, Connecticut, passed away on the morning of Friday, April 3, 2026, at Bryn Mawr Hospital in Bryn Mawr, Pennsylvania. He was the beloved husband of the late Angela Derrico Carabine and loving father to Caitlin Carabine McLean.

Michael was born on April 23, 1944, in Bronx, New York. He was the son of the late Thomas and Kathleen Carabine of New York.

Keep ReadingShow less
google preferred source

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

Chion Wolf brings ‘Audacious’ radio show to Winsted with show-and-tell event
Nils Johnson, co-founder and president of The Little Red Barn Brewers in Winsted, hosted Chion Wolf and her Connecticut Public show “Audacious LIVE: Show and Tell,” which was broadcast on April 8, drawing a sold-out crowd.
Jennifer Almquist

The parking lot of The Little Red Barn Brewers in Winsted was full on Wednesday, April 8, as more than 100 people from 43 Connecticut towns — including New Haven and Vernon — arrived carrying personal treasures for a live taping of “Audacious LIVE Show & Tell.”

Chion Wolf, host and producer of Connecticut Public’s “Audacious,” and her crew, led by production manager Maegn Boone, brought the program to the packed brewery for an evening of story-driven conversation and shared keepsakes.

Keep ReadingShow less
Marge Parkhurst, the preservation detective

Marge Parkhurst with a collection of historic nails recovered from wall cavities during restoration work.

Photo courtesy of Marge Parkhurst/Cottage & Country Painting Company
Walls still surprise me. If you look hard enough, you can find buried treasure.
Marge Parkhurst

After nearly 50 years of painting some of Litchfield County’s oldest homes and landmark properties, Marge Parkhurst has developed an eye for the past—reading the clues left behind in stenciled vines, forgotten bottles and newspapers tucked into walls, each revealing a small but vivid piece of Connecticut history.

Parkhurst was stripping wallpaper in a farmhouse in Colebrook — the kind of historic home she has spent decades restoring — when she noticed something odd. Three layers of paper had already come off — each one a different era’s idea of decoration — and beneath them, just barely visible under dull, off-white plaster, a pattern emerged.

Keep ReadingShow less
Wings of Spring performance at the Mahaiwe Theater
Adam Golka
Provided

On Sunday, April 19, at 4 p.m., Close Encounters With Music (CEWM) presents On the Wings of Song at the Mahaiwe Performing Arts Center in Great Barrington.

The program focuses on Robert Schumann’s spellbinding song cycle Dichterliebe (“A Poet’s Love”), a setting of sixteen poems by Heinrich Heine that explores love, longing, and the redemptive power of beauty. Featured artists include John Moore, baritone; Adam Golka, pianist; Miranda Cuckson, viola; and Yehuda Hanani, cello.

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.