pdated: March 25, 2011 2:14 p.m. |(15) Comments
The Army Corps Friday acknowledged that its electric fish barrier on the Chicago Sanitary and Ship Canal is not operating at a level high enough to repel all sizes of Asian carp.
A new report says lab tests reveal the barrier, which at the moment is operating at about half its maximum strength, would not be able to repel juvenile fish.
The reason the barrier isn't running full-throttle is the threat that electricity poses to canal barge operators in the area, many of whom are pushing flammable materials through the barrier, located about 35 miles south of Lake Michigan. The canal provides an artificial link between Lake Michigan and the Asian carp-infested Mississippi River basin.
"The current barrier operating parameters are effective for fish as small as 5.4 inches in length," an Army Corps of Engineers news release states. "The research published in this report suggests that slightly higher operating parameters than those currently in use may be necessary to immobilize all very small Asian carp, as small as 1.7 to 3.2 inches in length."
The report recommends cranking the voltage up to 2.3 volts per inch, but the Corps' Maj. Gen. John Peabody says "our current confidence level is very high" that there are no juvenile fish in the vicinity of the barrier.
The federal government also hasn't completed its evaluations of safety tests for operating the barrier at the higher strength, and Peabody said he won't greenlight the higher voltage until they are complete. That work should be done later this spring.
Peabody also stressed that the new tests showing the barrier is ineffective on small fish were conducted in a lab, and not on the canal itself.
"The lab research is just that - lab research," he said. "So it needs to be validated … with field research."
Charlie Wooley, deputy regional director of the U.S. Fish and Wildlife Service, said Friday that the best science shows the closest the juvenile fish could be to the barrier at this moment is about 25 miles downriver, and there are three navigation locks between that area and the barrier. The reason: There is no reason to believe there is a population of reproducing carp any closer than that.
Wooley added that no actual juvenile fish have been found within 116 miles of the barrier.
"We're already way too close for comfort," said Joel Brammeier, president of the Alliance for the Great Lakes. "We've known all along the barriers aren't adequate to achieve prevention. Do we really have to field test that question with the Great Lakes in the balance? I'd rather cut to the chase and fast-track the one solution - separation - we know will stop 100% of fish, big, small and in-between."
Duane Chapman, an Asian carp expert with the U.S. Geological Survey, said last month that his research shows that by the time a fish reaches six inches, it can swim at least 60 kilometers from where it hatched.
The Army Corps received a draft of Friday's report last fall, but initially declined to release it, saying it was only part of a series of studies evaluating the largely experimental barrier systems that are under way, and that the voltage study would not be released until all the others are complete.
Other reports will look at things such as barrier safety for barge operators and where the leading edge of the carp invasion is likely to be.
Peabody said the Army Corps decided to release it Friday because the lab work had been evaluated and was complete, so it was ready to be released. The Obama administration's "carp czar," John Goss, called the report "good news" because it adds to the federal government's understanding of the potential threats in the canal system.
Others don't necessarily see it that way.
"The Army Corps keeps repeating the refrain that its electric barrier is working, no matter what the evidence actually shows," said Thom Cmar, an attorney for the Natural Resources Defense Council. "We cannot pin the future of the Great Lakes on a science experiment. We need to move to separate the Lakes from the Mississippi River as soon as possible."
The electric barrier is considered the last line of defense between the giant jumping fish and Lake Michigan. The Army Corps is conducting a five-year study looking into how to rebuild the natural separation between Lake Michigan and the Asian carp-infested Mississippi basin that the Chicago canals destroyed over a century ago.
In the meantime, Army Corps officials have said the public need not worry because the barrier is working.
Even so, environmental DNA tests have for more than a year showed evidence of the carp in the canal waters above the barrier, and last summer fishing crews actually landed a specimen just a few miles from the Lake Michigan shoreline.
A lawsuit to force the Army Corps to slam shut two navigation locks near the Lake Michigan shoreline as a last-ditch effort is ongoing.