MONTREAL Like a slippery alien from
a science-fiction movie, the Asian carp, a fish species
that can grow four feet long (1.2 m), weigh up to 110
pounds (50 kg), and leap eight feet (2.4 m) out of the
water, could invade the Great Lakes where it would eat
its way through the ecosystem, experts warned Thursday.
Nonnative to North America, the carp are migrating
at the rate of 50 miles (80 km) a year up the Illinois
River toward the Chicago Ship and Sanitary Canal at
Romeoville, Ill., which connects the Mississippi River
system to the Great Lakes.
Fears are they could reach Lake Michigan this year,
according to the International Joint Commission (IJC),
a body established by Canada and the United States to
help protect the Great Lakes waterways the two countries
"The IJC believes that the Asian carp have the potential
to seriously damage or destroy the Great Lakes ecosystem
and that the threat is imminent," said Dennis Shornack,
chairman of the commission's U.S. section. "These fish
consume vast amounts of food. They are highly prolific
and can quickly grow to a size at which they have no
natural predators," he said.
Imported from China by southern U.S. fish farmers
in the early 1970s, the big carp have already cut a
swath through local species on its journey northward.
"Commercial fisheries in some parts of the Lower Mississippi
have been completely destroyed by the invasion of Asian
carp," Shornack added.
Experts said the fish can consume up to 40 percent
of their body weight daily in vegetation, zooplankton,
or native mussels and fish. Each female carries up to
1 million eggs, allowing the carp to quickly displace
natural species of fish in local habitats.
ONE CARP FOUND IN FOUNTAIN
Herb Gray, Canada's former deputy prime minister and
chairman of the Canadian section of the commission,
warned that a public education program is needed to
prevent people from introducing the carp into the Great
Lakes. Two live specimens have already be captured in
the area. "One bighead carp was collected in a net in
Lake Erie by scientists from the University of Guelph,
and another was found in a fountain in downtown Toronto,"
Three kinds of Asian carp silver, bighead, and
black escaped from U.S. fish farms into the Mississippi
River system during floods in the early 1990s. Used
in aquaculture to control algae and snail populations,
the carp population quickly bloomed in nature and began
moving northward to coolers waters that are their natural
The carp are now within 25 miles (40 km) of Lake Michigan,
and the best defense against them may be a $2.2 million
electric barrier built under the Chicago canal by the
U.S. Army Corps of Engineers. Originally designed to
keep another invasive species, the round goby, out of
the Mississippi, the barrier was turned on in April
2002 and uses a low-charge electrical current to repel
The problem is that the barrier is an experimental
prototype and is scheduled to be removed in October
2003. The design and funding also do not provide for
a backup generator to keep it operating in the event
of a power failure.
In a letter sent last week to U.S. Secretary of State
Colin Powell and Canadian Foreign Affairs Minister John
Manley, the commission called for immediate action to
block the Asian carp, including building a second, permanent
barrier in the canal.