For Second Time in Over 100 Years, Sea Lampreys Spotted Nesting in Norwalk River; Wilton Residents Invited to Special Tour of Rare Spawning Nest Sites

A pair of sea lampreys building a nesting site in the Norwalk River in Wilton. (photo: Mianus Chapter of Trout Unlimited video still)

For only the second time in over 100 years, sea lampreys have returned to the Norwalk River in Wilton. A pair of these native fish were spotted earlier this week building a spawning nest near Merwin Meadows.

Now, the Mianus Chapter of Trout Unlimited is hosting a special spawning nest tour this Saturday, May 21 from 1-3 p.m. at Merwin Meadows Park (52 Lovers Ln.). Residents are invited to register for the tour online.

Trout Unlimited members explain that while it may look a little strange, even ugly or scary, the sea lamprey is a native fish that is essential to the improving health of the local river systems.

These adult native fish, which spend their lives in saltwater but migrate into freshwater to mate, are now busy building spawning nests in the gravel throughout the river — especially in the area below the Strong Pond Dam on the river at Merwin Meadows where the dam is currently blocking their ability to swim any further upstream.

This summer, Save the Sound, Trout Unlimited, the town of Wilton, the State Department of Energy and Environmental Protection (DEEP) and a range of other partners hope to remove the Strong Pond Dam just north of Merwin Meadows Park to connect these two free-flowing stretches of water and restore fish passage from Long Island Sound all the way to Georgetown.

“The return of sea lamprey to the Norwalk River marks a turning point for our local waters,” said Jeff Yates, Conservation Chair of the Mianus Chapter of Trout Unlimited. “Not only do these fish represent a new hope for a restored watershed, but they also provide critical ecosystem services like bringing ocean nutrients miles upstream to fertilize our river valleys. Their spawning activity cleans and improves the gravel substrate of the river, making the spawning of other fish like trout and minnows easier and more effective.”

Residents, anglers and passersby are asked to please keep their distance and enjoy the return of these fish from a respectful distance. As a Connecticut State Endangered Species, it is illegal to harass, harm or capture them.

Each year, volunteers with Trout Unlimited scour the Norwalk River and area streams to identify and document sea lamprey spawning sites, as well as monitor other river conditions. To learn more, or to volunteer to be trained for this year’s effort, visit the Mianus Chapter’s website.

Founded in 1975, the Mianus Chapter of Trout Unlimited is a grassroots conservation nonprofit organization with more than 5,000 members and supporters in the towns of Greenwich, Stamford, Darien, New Canaan, Norwalk, Wilton and Ridgefield. The chapter works to protect and restore local river resources through active restoration projects, education initiatives and public advocacy.