Metuchen Removes Fast-Spreading Rare Invasive Plant From Historic Pond

METUCHEN, NJ — Metuchen has cleared an invasive aquatic plant from Tommy’s Pond after it spread across the water this summer, Mayor Jonathan Busch said.

The plant, known as common salvinia, formed dense mats on the pond’s surface. Last week, the borough finished a skimming project to remove as much of it as possible before winter.

“Residents are used to seeing some plant growth on the surface of Tommy’s Pond from time to time, including duckweed,” Busch said. “What we saw this summer was different.”

Left unchecked, common salvinia can block sunlight, lower oxygen levels, harm fish and native plants, worsen water quality and create more habitat for mosquitoes, according to the borough.

Removing the plant now also means less of it will rot in the pond over the winter. Decomposing plant material can lead to low oxygen levels, fish kills and bad odors, Busch said.

Tommy’s Pond was one of the first reported locations of common salvinia in New Jersey, according to the state Department of Environmental Protection.

“This is an unusual case,” Busch said.

It’s not clear how the plant got into the pond. “We are not exactly certain how the salvinia was introduced, but invasive aquatic species can spread in a number of ways,” Busch said.

The borough will keep an eye on conditions at the pond over the coming months as part of its regular maintenance, he said.

Tommy’s Pond has been part of Metuchen for more than a century. The Thomas family formally donated the surrounding park to the borough in 1929.

“Caring for it means understanding its natural cycles while also addressing threats like invasive species when necessary so this special part of Metuchen can be enjoyed for generations to come,” Busch said.

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