Sea lamprey gets new status: Vermont
By Candace Page
Burlingston Free Press
Published November 29, 2005
If Lake Champlain's sea lamprey could talk through those
ugly, tooth-filled, blood-sucking mouths of theirs, here's
what they'd be saying to Vermonters: "Nyah, nyah,
nyah, you newcomer flatlanders you."
Yes, it's true: Sea lamprey, long the lead villains on
Vermont's Most Unwanted list of invasive species, turn
out to be natives after all.
A team of Michigan State University researchers has established
that Lake Champlain lamprey are a genetically distinct
population old enough to be defined as native. The eel-like
fish probably swam up the St. Lawrence and Richelieu rivers
from the Atlantic Ocean and became landlocked in Lake
Champlain as long ago as 11,500 years, the researchers
"The evidence is convincing," said Brad Young,
a fishery biologist at the U.S. Department of Fish and
Wildlife in Essex Junction. "They have invasive-like
characteristics, but they are natives."
This is less than wonderful news for Vermont anglers.
"Even if they are native, they are ruining what
we are trying to do to get the lake fishing back to what
it should be," said Ed Braman of Colchester, an avid
fisherman of salmon, lake trout and walleye.
He said he feared the lamprey's new status would provide
fuel to those who want to stop Vermont's treatment of
streams with lamprey-killing chemicals.
But government biologists said they are not inclined
to give the "new" native a break.
"Unequivocally no," Young said. "Whether
it is a native or an invasive species does not affect
our position. We need to suppress the lamprey population
to support re-establishment of the fishery for salmon
and lake trout."
Champlain's lamprey numbers exploded in the past three
decades. Adult lampreys clamp their toothy, jawless mouths
on salmon and trout to suck their blood. At best, they
leave an ugly wound. At worst, they kill smaller and younger
The lamprey's newly established native status does generate
a new mystery: How did healthy populations of trout, salmon
and lamprey co-exist for thousands of years, and then
get so out of balance in the past 30 years?
Vermont's new natives
Some Vermont biologists have argued for some time that
lamprey are native to the lake. Their case was weakened
by the fact that there were no reports of lamprey -- or
of lamprey wounds on trout -- until the mid-1800s.
In the majority view, lamprey were a recent invader that
reached the lake by running up the Hudson River and through
the Champlain Canal after it opened in 1823.
Now comes Mara Bryan, a postdoctoral fellow and sea lamprey
researcher at Michigan State. She and a team set out to
compare the genetics of lamprey populations in the five
Great Lakes, Lake Champlain, New York's Lake Cayuga and
the Atlantic Ocean. They published their results recently
in a scientific journal, Molecular Ecology.
They examined DNA from 741 lamprey, including ones taken
from Lewis Creek in Vermont and the Great Chazy River
on the New York side of the lake.
"The Lake Champlain lamprey were very different
from everything else, and it takes a good amount of time
for things to become different," Bryan said.
"I'm 99.99 percent absolutely sure they have been
here longer than European settlers. The science is very
good on this," she said.
From native to pest
If lamprey have been in Lake Champlain so long, why have
they only recently become a pest?
"That's the $64 million question," said Mike
Winslow, a biologist at the Lake Champlain Committee in
Burlington. Human beings probably are as much to blame
as the lamprey, he and others said.
"It's likely lamprey were present in fairly low
numbers previous to us messing things up," Bryan
said. Native species like trout might have evolved ways
to co-exist with lamprey.
Brian Chipman, a fisheries biologist at the state Fish
and Wildlife Department, summed up the most common theory
for the lamprey population explosion in recent years:
In the 1800s, Vermont's new residents dammed up salmon-spawning
rivers that run to the lake and dumped sewage, sawdust
and other pollutants into the rivers. Commercial fishing
businesses swept trout from the lake with nets and spears.
By the early 20th century, salmon and trout populations
had crashed. Lamprey numbers probably crashed, too --
their main prey was gone and, like the salmon, their river
spawning grounds had been polluted -- so they were seldom
seen during the first half of the 20th century.
Then humans began to clean up rivers in the Champlain
basin. State governments started restocking the lake with
thousands of young lake trout and landlocked salmon --
a feast for lampreys.
"We expanded their food supply and improved water
quality where they spawn," Chipman said. "They
responded to that."
Controlling a nuisance
No one knows how many lamprey live in Lake Champlain.
"I'd say from tens of thousands to hundreds of thousands,
but it's hard to quantify," said Young, the federal
Rather than counting lamprey, biologists count the number
of fresh lamprey wounds they find on lake trout every
fall. Without lamprey control, biologists routinely find
60 or 70 wounds for every 100 trout they examine.
When Vermont and New York ran a control program in the
1990s, the wounding rate fell as low as 30 per 100 fish.
The control program stopped, and the wound rate skyrocketed,
peaking at 90 wounds in 2003. The goal is to reduce the
wounding rate on lake trout to 25 per 100 lake trout,
Lamprey might be natives, but their numbers are out of
balance for the ecosystem, Chipman and Young said.
Young said his agency would never set out to eliminate
a native species -- but no one thinks it is feasible to
extirpate lamprey in any case.
"We just want to manage their numbers to serve our
fishery restoration goals," Chipman said.
If lamprey have moved from the "invasive" list,
they've joined a substantial list of native species that
humans manage to prevent overpopulation or nuisances --
cormorants that have killed all other life on several
Champlain islands, whitetail deer that can overbrowse
their range, beavers whose dams flood roads and fields.
For lamprey, control means a regular schedule of chemically
treating rivers in New York and Vermont to kill the mud-buried
lamprey larvae. Those treatments have run into objections
from some environmental groups on grounds they could kill
other species in the rivers, a stand that makes some anglers
"Native" is usually a desirable adjective in
Vermont. So can no one find a kind word to say about lamprey?
"I think it is hard to quantify the benefit or role
of lamprey," biologist Young said.
Fisherman Braman thought for a minute. Don't people in
some cultures consider lamprey good eating? he asked.
"If they do, they can have them," he said.
Contact Candace Page at 660-1865 or firstname.lastname@example.org