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Why Vermont wants to protect the vampiric fish in the Connecticut River

 A sea lamprey swims near rocks in the Saxtons River in Westminster
Howard Weiss-Tisman
Vermont Public
A sea lamprey uses its sucker-like mouth to move rocks and pebbles around as it builds a nest in the Saxtons River in Westminster.

The sea lamprey doesn’t get a whole lot of love in Vermont.

And Will Eldridge, an aquatic habitat biologist with the Vermont Department of Fish and Wildlife, understands why.

“You know they are an underappreciated species,” Eldridge said one recent morning on the Saxtons River in Westminster, where Eldridge had come to study sea lampreys building nests. “A lot of people just, they don’t know what they are. They look scary. They’re intimidating.”

The parasitic, eel-like fish attaches its sharp teeth to other fish and sucks out their blood.

And that's fine in its natural environment.

But the state has been trapping and killing lamprey around Lake Champlain, where they have been feasting on native species like lake trout and Atlantic salmon.

More from Vermont Public: Lamprey control program hailed as success, as focus shifts to New York rivers

Here in the Connecticut River Valley — where the sea lamprey is a native species — Eldridge said it's worthy of respect, and conservation.

“Honestly we haven’t done a whole lot for lamprey,” he said. “I mean, this lamprey, their ancestors go back 400 million years. And it’s got a unique life history. It’s one that does migrate from Vermont, which is not a coastal state. It goes all the way to the ocean. And this is a species that connects Vermont to the ocean, and so it should be a more iconic species.”

The lamprey lays its eggs in the tributaries of the Connecticut — like the Saxtons River in Westminster — and after the baby lamprey hatch, they burrow themselves into the soft sand, where they live for five years or more.

They then swim down the Connecticut to the Atlantic Ocean, where they feast on sea life there, and after two or three years return, right here, back to the same tributary where their parents built a nest and laid their eggs 10 years ago or so.

The lamprey attach their mouths to pebbles and rocks, some as large as a golf ball, and drag them across the sandy river bottom to create a nest.

The female then lays tens of thousands of eggs in the center of the rock nest, and then the male fertilizes them.

After the nest is built and the eggs are in their place, the male and female parents die, and their bodies become an important source of nutrients, as well as food for other animals and birds, said Lael Will, a fisheries biologist with the Vermont Department of Fish and Wildlife.

 A woman walks below a dam on the Saxtons River in Westminster
Howard Weiss-Tisman
Vermont Public
Vermont Department of Fish and Wildlife fisheries biologist Lael Will walks below and old dam on the Saxtons River in Westminster. The state wants to remove the dam to open up more spawning grounds for the sea lamprey.

“They belong here, just like other critters belong here as well,” said Will. “And with the dams, you know, they’ve impacted their population. So what we’re trying to do is allow them access to spawning habitat.”

Will says dams along the Connecticut, and its tributaries, are preventing more lamprey from spawning.

The state is working with a nonprofit, the Connecticut River Conservancy, to remove old dams along rivers in the region.

And just upstream from where Will is watching lamprey spawn is an old dam that's slated to come down next year.

“So the hope is that when we get that dam removed that they will move into that good spawning habitat, they can spread out more, and be more successful,” Will said.

“They belong here, just like other critters belong here as well."
Lael Will, Vermont Department of Fish and Wildlife

But not all dams on the river are scheduled for removal.

Larger hydroelectric dams on the Connecticut River have fish ladders, but they were built specifically to allow fish such as shad and alewife to get through and swim upstream.

More from New England Public Media: Hydroelectric operator on the Connecticut River picks up key agreement in license renewal effort

But sea lamprey have a much tougher time getting up the ladders, and Will says the state is working with engineers and scientists to come up with better designs.

Will says there's a growing recognition of the importance sea lamprey play in the fresh water ecosystem of the Connecticut River Valley.

The work they do building nests helps clean the water and river bottom, and when they die their bodies, which are rich in ocean nutrients, are eaten by birds and other animals.

The Department of Fish and Wildlife is also working to get the word out that sea lamprey in the Connecticut River basin is a different population than the fish that have found their way to Lake Champlain.

“People don’t understand that this is a separate population,” she said. “And they see one, and they freak out, and they think it’s the nuisance population. And, you know, we want people to — don’t disturb them, that’s why we put press releases out every year. Like if you see one, don’t worry about it. They’re not parasitic. They’re not going to bite your toes. They’re just doing their job. They’re going to die, and just leave them alone.”

Along with removing and altering dams to make it easier for the lamprey to spawn, the Connecticut River Conservancy conducts sea lamprey nest surveys, where volunteers go out and count the nests. These surveys help the state record how its spawning projects are doing.

Will says the sea lamprey know what to do.

After all, they’ve been doing it for about 400 million years.

But, she says, they just need a little support and encouragement to deal with the various challenges that humans have put in their way.

Have questions, comments or tips? Send us a message.


Howard Weiss-Tisman is Vermont Public’s southern Vermont reporter, but sometimes the story takes him to other parts of the state.
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