In the fight against Asian carp, humans have long struggled to deter their formidable foe.
Large,
prolific and incredibly adaptable, silver and bighead carp have endured
netting, electrocution, poisoning and even a public relations campaign
to recast the scorned filter-feeder as a catch-of-the-day delicacy
fitting for the finest Chicago restaurants.
An electric barrier
erected in the Chicago Sanitary and Ship Canal is now the only thing
standing between the carp and Lake Michigan, where some fear the carp
may destroy the fragile Great Lakes ecosystem.
So in recent years, federal and state governments have decided to re-energize their carp-fighting campaigns.
Beyond
the Asian carp bio-bullet, new efforts include an underwater carp
camera, fine mesh nets intended to snare larvae and a large water gun
that creates a barrier by emitting sound waves under water. To lure the
carp to their deaths, scientists are also working on an enticing buffet
of female carp urine containing sex pheromones and highly concentrated
algae.
"I think we actually have a fighting chance," said Leon Carl, regional executive for theU.S. Geological Survey's Midwest area.
Scientists
don't want to stop at Asian carp either. They are now working to
develop a particle that could deliver a toxin to zebra mussels.
"We are looking at this as a production line," Carl said.
Although
he acknowledged that there are potential hazards to wading into such
new technological waters, Carl stressed that the payoff could be huge if
they are able to selectively kill invasive species.
"You are
risking the money and the fact that you might fail, but if you succeed,
the results are going to be very, very valuable," Carl said.
A
study by a coalition of Great Lakes states and cities has also explored a
more controversial solution: Permanently cut the fish off from Lake
Michigan by using sheet pile or impermeable land bridges that would
effectively re-reverse the flow of the Chicago River.
The
multibillion-dollar plan proposed three options that would be rolled out
in multiple stages over the next several decades. A 2010 lawsuit by
five Great Lakes states that is pending in U.S. District Court is also
seeking to close locks in the Chicago area.
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