Professor has cheap plan to stop invasive carp, but needs money now
ST. PAUL — The carp invading Minnesota up the Mississippi River can be stopped — at least for several years.
It’ll only cost $60,000.
But the man with the plan — University of Minnesota researcher Peter Sorensen — doesn’t have the money.
And he needs it now for it to work.
“We’ll take money from wherever we can get it,” said Sorensen, who heads the Minnesota Aquatic Invasive Species Research Center at the university’s St. Paul campus. “We need to put these things in the water as soon as possible.”
Those “things” are five transducers — underwater speakers — that Sorensen and his team want to install at Lock and Dam No. 8 near Genoa, Wis.
Bighead or silver carp, possibly both, are successfully breeding below the dam, researchers discovered last month. But there’s no evidence the fish, often called Asian carp, are breeding above it in Pool 8, which extends north along the Minnesota-Wisconsin border to La Crosse, Wis.
Sorensen and his team, including Ph.D. student Dan Zielinski, have discovered that the carp are sensitive to — and annoyed and deterred by — sounds not heard by most other fish. The speakers would play those sounds just downstream of the lock, which is the carp’s most likely doorway farther into Minnesota.
“Our goal is to design a deflector shield around the lock,” Sorensen said.
Time is of the essence, he said, because bighead and silver carp swim upstream to spawn, and spawning will begin this summer.
Sorensen’s traditional sources for money — the university and the state legislature — don’t turn around funding rapidly, so Sorensen is now hat-in-hand, asking for donations, which would be handled through the University of Minnesota Foundation (giving.umn.edu).
The transducers are part of a larger plan developed by Sorensen to slow or halt the spread of the carp, based on research by his team that discovered two vulnerabilities of the fish: They have sensitive ears, and they don’t swim that fast.
Carp have “hearing” that’s 10 to 100 times better than all native fish except catfish, thanks to a rib bone that vibrates against the fish’s swim bladder, essentially turning the organ into a large eardrum. Using live carp and a tank that looks like a hot tub, Zielisnki discovered that by playing combinations of louder and softer low-frequency sounds — a din similar to a boat motor — he could not only annoy carp but deflect them.