Asian Carp May Spread Through Great Lakes
ENVIRONMENT: Non-native fish
new in the neighborhood
Massive carp that have been
known to jump some 10 feet out of the water and wallop
boaters in the Mississippi River have been spotted in
Lake Erie, raising fears that the nonnative species may
spread throughout the Great Lakes. The bighead carp are
just another example of invasive species threatening ecosystems.
In Maryland, it was snakeheads
predatory fanged fish from Asia that are able to
move on land. Flathead catfish, native to western Pennsylvania
waters, have been caught in the Susquehanna and Schuylkill
rivers. And several pacu, a mostly vegetarian cousin of
the piranha, were caught in the Ohio River near Pittsburgh
While some nonnative fish
are probably dumped from home aquariums and unable to
survive for long which state fish biologists think
was the pacus' fate fisheries experts say invasive
fish have the potential to cause havoc with aquatic ecosystems.
"They can compete and
sometimes out-compete with the native wildlife
for food in that area, which can throw the ecosystem off,"
said Mitch Snow, a U.S. Fish and Wildlife Service spokesman.
That happened with zebra mussels.
Brought to the United States
in the ballast water of oceangoing ships in the 1980s,
zebra mussels spread rapidly through the Great Lakes and
other inland waterways and have caused millions in damage
to power plants and boats.
Only a couple of bighead carp
have been caught in Lake Erie, though some biologists
believe they spotted one July 17.
Robert Wellington, an aquatic
biologist with Erie County health department, was with
some colleagues and a group of students in Presque Isle
Bay when a massive fish surfaced.
"I would estimate that it
could have been between 30 and 50 pounds," said Wellington,
a lifelong angler. Others in the boat said it was about
5 feet long. "It was a tremendous fish," he said.
Though they tried to catch
it, they couldn't.
"Until you get it in your
hands, it's pretty much a fish tale," Wellington said.
Chuck Murray, a biologist
with the Pennsylvania Fish & Boat Commission, said the
fish sounded like a bighead carp, though he isn't that
familiar with it.
The fact that so few have
been caught or spotted indicates they have not been able
to breed, he said.
Marc Gaden, a spokesman for
the Great Lakes Fisheries Commission, said most biologists
believe the bighead carp sightings in Lake Erie have been
But fisheries experts fear
they will adapt eventually to the Great Lakes. Bigheads
have been spotted as close as 25 miles from Lake Michigan
in a canal connecting the lake to the Illinois River,
a tributary of the Mississippi.
The Army Corps of Engineers
has erected an electrical barrier that hopefully will
stop the fish, Gaden said.
"This has all the makings
of another zebra mussel," he said. "Once the species makes
the Great Lakes their home
you can't get rid of
Bigheads were imported from
Asia in the 1970s and 1980s to control plankton in fish
farms in the south, said Jerry Rasmussen, a biologist
with the U.S. Fish and Wildlife Service and a coordinator
with the Mississippi Interstate Cooperative Resource Association.
"I've seen them jump into
boats and I've seen them jump 6 to 10 feet into the air,"
he said. "They're pretty astounding."
Though he hopes the barrier
works, he said there's a good chance they'll get in.
Snakeheads are believed to
have been eradicated from the Maryland pond in which they
were found. They are in Florida waters and are sold live
in some pet shops.
While it's always been illegal
to release live snakeheads into the state's waterways,
the commission is making it illegal to sell or possess
the fish, said Dan Tredinnick of the Pennsylvania fish
commission. Snow said the federal government has proposed
a similar measure.
The threat or benefit
of nonnative fish isn't new.
Sport fish such as rainbow
and brown trout and smallmouth bass were introduced into
Pennsylvania waters more than a century ago.
"A century ago, the idea was,
'Let's see what we can grow here,' but the view of how
fisheries should be managed has changed," Tredinnick said.
It is "not very likely" that
bighead carp have reached Lake Superior, said Jay Rendall,
exotic species program coordinator for the Minnesota Department
of Natural Resources.
"We've been expecting to see
the bighead and silver carp in the Mississippi River in
the southernmost part of Minnesota," Rendall said. "Boaters
and anglers should expect to see them there this year
Anyone who believes he or
she has caught a bighead carp in Minnesota should take
the fish to the local DNR Fisheries office for identification
or call the Exotic Species Program at (651) 296-2835,