Last Year's Mass Release of Invasive Water Chestnut Bears Fruit on the Lower Connecticut River - The Connecticut Examiner

2022-09-23 19:56:34 By : Ms. Jodie Xu

A mass release of invasive water chestnut plants last year from a flood control pond in Hartford appears to have caused new infestations of the plant along the Connecticut River this year, according to environmentalists in the region who have been working to remove the plant.

Anticipating heavy rain from the remnants of a tropical storm last August, Hartford was forced to pump out a flood control pond that was heavily overgrown with water chestnuts. And while the city said it used an excavator to scoop the thick mat of plants off the water so they wouldn’t end up in the Connecticut River, boaters and conservationists reported large mats of the plant floating down the river soon after.

The impact has been clear, said John Hall, who runs the nonprofit Jonah Center for Earth and Art in Middletown. New plants started popping up in places that had previously been spared from the water chestnuts – from a large patch just downstream of the flood control pond in Hartford’s North Meadows, down to near Essex’s North Cove, at the edge of where the water of the tidal river turns brackish and water chestnuts can’t survive.

Hall has served as a sort of dispatch center for the network of smaller, mostly volunteer groups that take part in the water chestnut removal effort along the Connecticut River. 

Hall fields queries from kayakers, boaters and homeowners along the river, and points groups like Friends of Whalebone Cove in Lyme or Connecticut River Conservancy in the right direction. 

“Now we have a much bigger problem,” Hall said. “It’s spread over a bigger area, and one of the challenges is that these new plants are emerging in many areas that are not easy to reach by kayak, and you have to paddle maybe an hour in order to get to them from a public launch site.”

For years, the invasive and prolific water chestnut has been a scourge on the coves and inlets of the Connecticut River – which provide still bodies of freshwater that the plants can cover in a dense mat of vegetation if left unchecked.

These 2-4-inch thick carpets of water chestnut block out native aquatic plant and animal life, and they also make it more difficult for a boat or a fishing line to break through. In localized problem areas, groups of dedicated volunteers have come together to get the plants under control – like in Selden Cove in Lyme, where the Friends of Whalebone Cove organize volunteers every summer to pull the plants out of the water.

Keeping water chestnuts under control in even one area is an annual battle. The plants are prolific, and each can produce up to 120 seeds in a single year. 

Humphrey Tyler, who has been involved in the cleanup with Friends of Whalebone Cove, said that on the eastern bank of the river, new infestations cropped up below the old Connecticut Yankee nuclear plant in Haddam, and in the mouths of the Salmon River, Selden Cove and Hamburg Cove.

Tyler said the places where they found new infestations correlated with where plants released from the Hartford holding pond would have ended up – along the main stem of the Connecticut River, and in the mouths of the tributaries, coves and bays that line it.

“There’s every reason to believe that’s where they came from,” Tyler said.

In their native ranges in Europe, Africa and Asia, water chestnuts are kept in check by insect parasites, according to Penn State Extension. But in the U.S., if the plants aren’t pulled between when they begin to flower in July and when they start to drop their seeds in the water around mid-August, they will continue to reproduce exponentially each year.

Most of the seeds will create new plants within two years, but they can take as long as 12 years to germinate, so even when it appears a body of water has been cleared, the plants could still come back the next year, Hall said.

“The Hartford release made it worse and spread it over a larger area, but it’s not as if we didn’t have a water chestnut problem before that,” Hall said. “It’s quite a challenge. If these plants aren’t managed, they can really take over a river and become a very expensive thing to deal with.”

Margot Burns, environmental planner with the Lower Connecticut River Valley Council of Governments, said there was an impressive, all-out push from the various groups that make up the water chestnut control effort this year to try to limit the impacts of the Hartford release. 

“I think that we dodged a bullet this year because of the outreach effort and the volunteer effort,” Burns said.

It’s satisfying work, Hall said — often done alone in the early morning on the river, when high tide makes it easier to reach shallow coves. It’s satisfying for someone to be able to easily see the impact they’ve made.

“But this isn’t the kind of thing that you can sustain with volunteers, year after year, because it is hard work and people get kind of tired and burned out doing it for too long,” Hall said. “So we do need to have the government put up money to hire workers to keep at this long-term because this problem isn’t going away.”

Burns said the state has started to move in the right direction, using funds from a new boat stamp to fund projects aimed at removing aquatic invasive species, including water chestnut and hydrilla. But that alone isn’t enough to manage the problem, she said.

“They really need more funding than that. Connecticut is a water-rich state, with lakes and ponds and reservoirs that all need to be watched,” Burns said. “We need not just more people to do that, but they need equipment – they need boats, trailers and trucks.” 

Especially on the Connecticut River, where all the coves and inlets are connected by the main stem, there needs to be a unified, coordinated effort to approach the water chestnut issue, Burns said.

The Connecticut River Conservancy has been one of the few organizations providing professional assistance to the water chestnut removal effort, hiring seasonal staff that took on a notorious infestation at Keeney Cove in Glastonbury. 

Next year they hope they’ll be able to secure enough funding from the state and federal governments to double their seasonal staff, and to buy flat-bottom jon boats to help transport pulled plants from the somewhat remote locations where volunteers and staff are in kayaks pulling them by hand, the conservancy’s Connecticut river steward Rhea Drozdenko said.

“It’s an increase of manpower, an increase of time that we can spend out there,” Drozdenko said. “We also hope to start our season a little bit earlier, maybe May or June, so we can really pull up the plants before the seeds start to grow.”

Brendan Crowley covers energy and the environment for CT Examiner. T: 860 598-0050

Copyright © 2022  •  Design by Julia Balfour, LLC