Alien invaders creep
Sunday, July 28,
THE SAGINAW NEWS
Daniel Manyen was "kind
of shocked" by what he saw.
A 4-inch-long sea lamprey
hung off the fin of a walleye fished from the Tittabawassee
River near Dow Chemical Co.'s dam in Midland County last
Normally, the Essexville
charter fishing captain would spot the parasitic lamprey
-- which feeds mostly on trout and salmon -- on the high
seas of northern Lake Huron.
But the tax-paid war
against the parasitic eel now occurs on inland rivers
and streams, often many miles away from the open waters
of the Great Lakes and its more than $2 billion a year
sport fishery industry.
"They're a multimillion-dollar
problem in Lake Huron," said James P. Baker, fisheries
supervisor of Bay City office of the state Department
of Natural Resources. "They prey on desirable fish."
That's a concern for
charter captains such as Manyen, 50, and Larry Lienczewski,
52, of Linwood, who depend on fishing excursions for their
Anglers have reported
"quite a few" lampreys scarring salmon this season near
Oscoda, "which is really unusual," Lienczewski said. "Usually
they don't come down that far."
Officials have no estimates
of how much damage the predator causes.
Still, Manyen and Lienczewski
said encounters with sea lampreys are uncommon.
have proven effective, although it's not realistic to
expect the annihilation of the species in the lakes, said
Paul H. Wendler, a former Saginaw mayor and adviser to
the Great Lakes Fisheries Commission.
One lamprey can lay
thousands of eggs.
"We have knocked the
lamprey down, but we will never, never eliminate the lamprey,"
An alien invader
Sea lampreys, ancient
creatures that invaded the four Great Lakes that border
Michigan with the completion of the Welland Canal in the
19th century, spawn locally in Saginaw River tributaries
and use the waterway as a highway to Lake Huron.
lake trout by the 1950s, and they recovered only because
of restocking programs, Baker said. The U.S. Fish and
Wildlife Service dumps more than a million trout yearlings
and more than 3 million salmon annually into Lake Huron.
Typically greenish or
gray, sea lampreys usually flourish in clear-water rivers
and creeks that have gravel beds. The predators hunt in
outer Saginaw Bay and Lake Huron for smooth-scaled fish
such as trout and salmon, anglers say.
The toothy vampire-like
creatures suck blood and fluids from their prey, consuming
40 pounds of fish in an adult lifespan of roughly 18 months.
It's not surprising
sea lampreys were found near Dow Dam, where 500 were caught
in a trap this spring, said Dennis S. Lavis, a sea lamprey
expert at the U.S. Fish and Wildlife Service biological
station in Ludington. The Chippewa River, a known lamprey
spawning ground, joins the Tittabawasee near the dam.
Federal officials treat the Chippewa every few years to
keep the predator population from exploding.
Saginaw County predators
Federal wildlife workers
took a survey of the muddy brown Cass River near Frankenmuth
this summer, but did not find enough larvae to justify
a lampricide treatment, Lavis said.
Workers last treated
the river in 1984.
"They need clean, clear
water to reproduce," Manyen said. "I hate to say this,
but it's almost a compliment to the river system if you
do see them."
The St. Mary's River
connecting Lake Superior and Lake Huron acts as a hotbed
for lamprey spawning, officials said.
In mid-Michigan, federal
wildlife workers also fight the predators in the Big Salt
River, Carrol Creek, and Little Salt Creek in Midland
Workers don't treat
the Saginaw River because lampreys don't spawn in the
That wasn't the case
in the Shiawassee River near Chesaning, where crews poured
2,260 gallons of trifluoromethyl nitrophenol -- a lampricide
-- to kill an estimated 12,800 larvae this spring.
Treatments have caused
"a little controversy" in some areas because they have
on occasion killed unintended targets -- namely, fish,
In 1997, the lampricide
killed a large number of white suckers and carp on the
Shiawassee because the restricted-use pesticide reacted
with the changing acidity of the river, said Alex Gonzalez,
a supervisor at the U.S. Fish and Wildlife Service in
"It was substantial
enough where we had to go back and pick up the dead fish,"
Biologists test a river's
acidic content before adding the lampricide. They must
wear rubber gloves, aprons and rubber boots when handling
it, he said.
"We have not had any
report of any problems with humans or mammals because
of this chemical," he said.