Effort to remove invasive aquatic weed from Connecticut River underway

Aug. 16—CHESTER — The Connecticut River, so often considered a line of division between the eastern and western parts of the state, has become a unifying force as local, state and federal groups come together to fight the uniquely resilient aquatic weed known as hydrilla verticillata.

A coalition of government and nonprofit groups is moving forward this month with a plan, led by the United States Army Corps of Engineers, to conduct preliminary, nontoxic dye tests at several sites, including Selden Cove in Lyme, as a precursor to potential herbicide application next year.

The water in Selden Cove will run red later this month as scientists work to better understand how the dye, which mimics the flow of herbicide, will travel through the cove toward Selden Creek and the river.

Joe Standart, a resident of Selden Cove, said over the phone Wednesday that the number of thick mats of unsightly weeds will soon peak, continuing to clog the engine of his powerboat and rendering the cove impassable.

He said it's been about four years since residents became aware of the problem, with each summer worse than the last.

Standart said sport fishermen he's seen in past years on their own or as part of contests have not come around this summer. He described hydrilla as both an ecological and economic problem.

"It was so bad last year I can't imagine it getting worse," he said.

He predicted wall-to-wall weeds in the cove by next week.

Selden Cove is slated for the dye treatment on Aug. 29, according to the Army Corps of Engineers.

Gregory Bugbee, an associate scientist with the state's newly formed Office of Aquatic Invasive Species, joined U.S. Sen. Richard Blumenthal, D-Conn., state Rep. Christine Palm, D-Chester, and assorted scientists and conservationists Wednesday at Petzold's Chester Boat Basin to tout the efforts to eradicate hydrilla.

Bugbee said the first dye test, which was conducted at Keeney Cove in Glastonbury, resulted in a pinkish-red hue to the water for a short period of time.

"It's not like you're going to see blood red water or something coming down the river," he said.

Palm, the state representative Bugbee described as integral to the creation of the Office of Aquatic Invasive Species, said the plant's common name, water thyme, belies its destructive nature.

She said its characteristics sound like those of a superhero or a cartoon monster.

It can thrive in poor conditions, causes algae blooms and is capable of growing several inches a day.

"It even hosts cyanobacteria that actually can punch holes in the brains of eagles," she said. "It sounds like something made up for science fiction. It's not."

The new aquatic invasive species office is part of the Connecticut Agriculture Experiment Station, which in a 2021 report said hydrilla has been linked to neurotoxins that may have caused the deaths of hundreds of bald eagles in South Carolina and Arkansas over decades.

Bugbee said DNA sequencing has shown the strain of hydrilla in Connecticut is unlike any other in the world. The highly invasive plant currently covers about 1,000 acres of the Connecticut River system, engulfing entire coves and tributaries so they are "basically impassable."

He said the extent of the problem dictates that the use of herbicides must be looked at "very, very closely."

The intent of the dye test is to determine the safest, least toxic way to contain the problem if herbicides are used, according to Bugbee.

He said he's aware of the controversies surrounding herbicides but said they have to be "on the table" due to a lack of better options.

The Connecticut River Conservancy said hydrilla was first identified in the Connecticut River in 2016 in Glastonbury. It degrades water quality, chokes out native plant species and can destroy the habitat for migratory fish like shad and herring.

The invasive species is especially resilient because it spreads through fragmentation, which is a form of asexual reproduction or cloning, and can travel downriver on paddles, boats and wildlife, according to the conservancy. It can also spread to other water bodies on boats if the vessels aren't properly cleaned, drained and dried before being used again.

Blumenthal said he plans to ask for $25 million to control the invasive weed as part of the appropriations bill currently being drafted by the U.S. Senate. That's up from $6 million in federal funding included in the 2023 omnibus spending bill and $1 million allocated in 2022 for controlling hydrilla in the Connecticut River Basin.

He called the aquatic invasive species a long-term problem that needs a sustained commitment from the federal government.

At the state level, the Office of Aquatic Invasive Species was created in 2022. Palm said the Connecticut General Assembly allocated approximately $600,000 per year to run it.

Diane Fiske, president of Friends of Whalebone Cove in Lyme, said the group first found out about hydrilla in Whalebone Cove and Selden Cove while they were pulling out the invasive water chestnut species several years ago.

Water chestnut is an annual that can be pulled up and disposed of and never be seen again, she said. Her volunteer group has been successful with organized "pulls" to extract the invasive plants before they drop their seeds late in the summer.

But hydrilla can't be controlled by individuals or small organizations the way water chestnut can. That's why she said her group supports the dye testing.

She said the topic of herbicide use will need more conversation when the time comes, but the Friends of Whalebone Cove is endorsing testing now "because something has to be done."

State Rep. Devin Carney, R-Lyme, emphasized Wednesday the unified front against hydrilla that includes a variety of interests on both sides of the river, including Republicans, Democrats, marine owners and environmentalists.

"Everyone dislikes hydrilla," he said.

e.regan@theday.com