controls a concern for some
By Peter Rebhahn
Green Bay Press Gazette
The double-crested cormorants that call the bay of Green
Bay home six months out of every year are now kicking
up their heels in the warmth and sunshine of the southern
But, come spring, they’ll be back, and they’ll bring
their fish-eating natures with them.
"We have way too much of a good thing," said
Mark Maricque, the biggest of the 17 commercial fishermen
awarded yellow perch harvest quotas by the state Department
of Natural Resources for the 2002-03 season.
"In the minds of commercial fishermen and, I think,
most of your organized sport fishermen, without a doubt
the cormorants are having an impact on yellow perch."
According to the latest reliable estimate there are around
8,000 nesting cormorant pairs, plus or minus 20 percent,
in the bay and nearby Lake Michigan waters - far more
than the 50 nesting pairs biologists counted in the 1970s,
when the bird appeared on Wisconsin’s Endangered Species
Yellow perch numbers, on the other hand, have spiked
and plummeted in the past 30 years, but the overall trend
has been downward, raising speculation that the fish-eating
cormorant may be the reason.
Last month the U.S. Fish and Wildlife Service made final
a ruling two years in the making that allows Wisconsin
and 23 other states to use lethal force to control cormorant
populations where necessary.
The ruling means states no longer need federal permits
to kill cormorants, whose management is under jurisdiction
of the U.S. Fish & Wildlife Service under the federal
Migratory Bird Treaty Act.
But Wisconsin has no plans to move willy-nilly into lethal
cormorant control next spring, and may never take that
"We’ll have to work through some kind of process,"
said Bill Horns, the DNR’s Great Lakes fisheries coordinator.
"That will entail some significant costs we can’t
really afford right now."
The problem, said Horns, is that there’s no sound evidence
that cormorants are behind the precipitous drop in yellow
perch numbers recorded by DNR biologists since the late
1990s, and getting the proof would require studies the
cash-strapped state agency can’t afford.
Bill Willis, president of the 200-member Green Bay Area
Great Lakes Sport Fishermen and an advocate of cormorant
controls, thinks Wisconsin and other states got a raw
deal from the federal government.
"Basically, they’ve washed their hands of the problem,"
Fish & Wildlife 'dragged its feet' on the control
issue allowing the problem to worsen, Willis said, then
dumped the problem into the states’ lap.
"It’s not going to cost them (the federal government)
money now," Willis said. "They’re going to put
the problem on the states, and we’re already strapped
the way it is."
Green Bay-based Fish & Wildlife biologist Ken Stromborg
is in the third year of a long-term study aimed at determining
how well the bay’s cormorants are surviving year-to-year
- a piece of information he said is vital to any decision
to kill cormorants.
"I’m a wildlife manager, and I don’t have an objection
to a well-reasoned and scientifically based management
plan," Stromborg said. "That doesn’t bother
me at all. What bothers me are knee-jerk reactions that
aren’t based on solid informational footing."
Fishermen like Maricque and Willis have heard the charge
before that their calls for cormorant control are based
on anecdotal stories of cormorants gorging on perch that
lack scientific certainty.
Willis pleads guilty to not being a scientist, but said
he and others in the group he leads only need common sense
to understand the problem.
"They’re not particular what kind of fish they eat,"
Willis said. "If the yellow perch are there, cormorants
are going to eat the perch."
And so they do, Stromborg said. But he said there’s a
big information gap between the angry observations of
disappointed fishermen and good scientific evidence.
"It’s clear that cormorants did not cause the perch
problem," Stromborg said. "That should never
have been on the table. I understand that it is, and I
understand why. But there are no data to support it."
Ornithologist Tom Erdman, curator of the Richter Museum
of Natural History at the University of Wisconsin-Green
Bay and a keen observer of the cormorant issue, said that
there’s better evidence that big catches by ice fishermen
in the 1990s created today’s perch shortage.
But Erdman said the biggest cause for declining perch
numbers is probably changes in the bay, where invading
nonnative species have upset the ecological balance by
interfering with millennia-old predator-prey relationships.
"There’s a lot of things that have happened in the
bay of Green Bay since the good old days," Erdman
It’s unlikely that Wisconsin will put together a cormorant
control plan for 2004, Horns said. "But I’d never
want to say never," he added.
Horns said if the state does enact controls, the method
of choice is likely to be egg-oiling, not shotguns. Environmentally
safe cooking oil sprayed onto eggs plugs the microscopic
holes bird embryos need to breathe, killing them.
Willis said his group has offered to help the DNR to
lessen the hit on taxpayers’ wallets. "I wouldn’t
have any problems getting volunteers, and I’ve even offered
to pay for the oil," Willis said.
More volunteers might come from the ranks of commercial
fishermen, whose near-unanimous attitude toward the need
for cormorant controls Maricque condensed into a few words.
"The time has come and gone," Maricque said.