Whalebone Cove Organizes Grassroots Effort on Invasives in the Connecticut River

Whalebone Cove


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LYME —“It started with eight people around a dining table and grew to thirty-five volunteers that pulled 5,000 to 6,000 invasive plants out of a cove last summer,” said Diana Fiske, a member of Friends of Whalebone Cove, a nonprofit formed to preserve and protect the ecological integrity of the cove, which has been threatened the increasing growth of non-native invasive plants. 

The first meeting was in 2015 and now the group has grown to about 100 members who decided last year to take a more scientific approach to solutions for Whalebone Cove, an inlet just downriver from where the Chester-Hadlyme Ferry crosses the Connecticut River in Lyme.

“Three years ago we got a college student to make a list of the invasives she found in Whalebone Cove and from that report we decided we needed a marine botanist,” said Humphrey Tyler, a member of the group, who with Fiske, and member Greg Miller, visited CT Examiner’s office on February 18. 

The friends group raised $3,000 from the Connecticut River Conservancy to fund a 2019 study of invasive plant species in Whalebone Cove by Judy Preston, an environmental consultant and Connecticut outreach program coordinator for the Long Island Sound Study and Connecticut Sea Grant. 

Preston identified seven plants that have the potential to significantly affect the biological integrity of Whalebone Cove: (in order of threat) Hydrilla, knotweed, water chestnut, yellow iris, milfoil, loosestrife and phragmites. 

Water chestnut and hydrilla choking the water (Courtesy of Friends of Whalebone Cove)

But Preston’s first two recommendations to the Whalebone Cove group were practical: “Be prepared for the long haul” and “Get connected.” 

“I so believe in community-based conservation. It’s one thing to save pandas and condors and that sort of thing, but it’s your backyard that really evokes a sense of pride and the need and want to protect, and that’s the most effective place where conservation is going to happen,” she said by phone on February 20. 

For Whalebone Cove, Preston recommended checking the spread of invasives to tolerable levels and avoiding large-scale mechanical or chemical removal that could cause disturbance to native species.

“For a lot of these species it’s never going to be a zero-sum game and they’re never going to eliminate it so they’re going to have to manage it. That’s a whole different mindset,” said Preston. “And it’s aggravated even more by the prospects of climate change because a lot of these species are already adapted to a warmer environment.

Preston described the non-native invasives as “aggressive and very successful.” 

“They’re that much more ahead of the game because they’re not here coupled with their native enemies,” she said. “A lot of these are coming from Southeast Asia or Europe, or just not this country, which is interesting because we send our fair share of species back in those parts of the world, too, which is in part why we just know that it’s not ever going to be completely solved.”

What if we do nothing?

An “impenetrable mat of vegetation” will eventually cover the Whalebone Cove if humans do nothing to manage the invasive plants, Preston concluded in her report.

According to the report, a combination of hydrilla, water chestnut and milfoil can form a dense mat on the water surface and below that can “drive out native plants, increase water temperature, raise pH, lower dissolved oxygen levels, inhibit water movement and mixing and impact gas exchange with the surface atmosphere.”

Vegetation decomposing in the fall can lead to “low oxygen and potentially anoxic conditions at depth, killing off or driving out subsurface aquatic life.” 

These changes “alter wildlife food webs and habitat, can eliminate spawning and feeding areas and fundamentally change the composition and function of the freshwater tidal marsh animal and plant life community,” she wrote. 

Preston said invasives will affect recreational activities, including boating by restricting “the use and maneuverability of paddle craft and motor boats.” The degraded habitat will lower the availability of fishing. Invasives will crowd out wild rice and river bulrush that local and migratory birds use for food and habitat, affecting hunting and birdwatching. The stagnant water will provide a breeding ground for mosquitoes.

“There will be winners and losers and what we will lose is the total diversity of species. The more diversity — the more safety to allow for change. And we’re going to need all the diversity with climate change,” she said. 

Taking action

Last summer Friends of Whalebone Cove learned that Selden Cove, located about one half mile downstream from Whalebone Cove, was overrun with the Eurasian Water chestnut (Trapa Natans). 

Each water chestnut produces 10 to 15 seed pods, and each seed pod can produce 15 new plants, said Fiske. 

“We organized a strike on Selden with Diana and the others,” Tyler said. “We had 10 ‘pulls’ organized to get all of the water chestnut out. That was 5,000 to 7,000 plants.”

Kayakers with trash bags paddled into the cove, pulled and bagged invasive plants and paddled back to a waiting motor boat to unload, a cycle that repeated many times.  

Susan Tyler collecting invasives (Courtesy of Friends of Whalebone Cove)

Fiske said that the operation required significant planning, the availability of kayaks, a motor boat with permission to land, and a place on land to dispose of the invasives removed from the water. The entire operation needed to take place at high tide.

Helping coordinate the effort, the Connecticut River Conservancy has been organizing task forces, and Friends of Whalebone Cove has agreed to be responsible for Chapman Pond, Selden Pond and Whalebone Cove. 

Preston said volunteers are needed for coves along the Connecticut River and elsewhere. 

“Maybe adopt a cove or make it a point to come out and help,” she said. “There are many ways to help. If you can’t get on the water, maybe you help with the lugging the plants to a place that’s away from water.” 

For Whalebone Cove, Tyler said the costs of controlling invasives is unknown. “This is going to be an ongoing annual task,” he said. 

For anyone interested, Preston recommended contacting the Connecticut Invasive Plant Working Group.

“It starts with pulling one plant at a time,” she said.

For more information, Friends of Whalebone Cove President Diana Fiske can be reached at 860-322-4757 or by email at fowchadlyme@gmail.com