Even as Michigan lawmakers lambaste the U.S. Army Corps of Engineers for not moving fast enough to develop a permanent plan to stop Asian carp from swimming up the Chicago canal system and into Lake Michigan, genetic evidence that the fish are on the march continues to grow.
Tuesday the Army Corps announced it would send fishing crews onto the North Shore Channel of the Chicago River. The agency also will fish for Asian carp on a six-mile stretch of river in downtown Chicago.
The announcement was triggered after three separate sampling trips on the waterway showed DNA evidence of silver carp, which can be shed from a live fish from things such as mucus and feces. The agency also announced Tuesday that 17 of 57 samples taken on just one trip last month on the Chicago River near downtown tested positive for silver carp.
Crews will be on the river next week with electro-fishing boats and other sampling tools to chase the elusive fish. The Army Corps maintains that a positive sample does not necessarily mean the presence of live fish. Officials note it could get in the water by some other means, such as barge bilge water, bird droppings or even the toilet flush of someone who happened to eat Asian carp for lunch.
“While the science still does not tell us whether (a positive DNA sample) is from a live fish, a dead fish, or another source, finding three consecutive sets of positive samples triggers us to use significant resources to determine whether any Asian carp are present,” John Goss, the White House’s Asian carp boss, said in a news release.
While the Obama administration has doubts about what a positive DNA hit means, the scientists who developed the genetic fingerprinting technique for the invasive fish say the only way to explain so many positive samples in so many places at so many different times of year during the past three years is that at least some fish have breached an electric fish barrier on the Chicago Sanitary and Ship Canal, about 35 miles downstream from Lake Michigan.
The controversy was the subject of a Journal Sentinel series this year.
This year there have been 80 positive samples for silver carp DNA, one of two species biologists fear are poised to invade Lake Michigan via the Chicago canal system.
Beyond the Chicago canals, there are 18 potential pathways across the region where the waters could merge between the once-separated Great Lakes and Mississippi River basin, but none at this point are considered high-risk migration pathways for the giant carp that were imported by Southern fish farmers to the U.S. from Asia decades ago.
The Army Corps is in the middle of a multiyear study evaluating how to block the carp and other unwanted species from migrating between the Great Lakes and Mississippi River basins, and this summer Congress ordered the Army Corps to expedite that study and come up with a potential solution by the end of 2013.
The Army Corps responded last week that it would pick up the pace of its study, but that no firm plan could be crafted by that deadline.
Authors of the legislation reacted with frustration to the Army Corps’ response, with U.S. Sen. Debbie Stabenow (D-Mich.) calling it unacceptable. And on Tuesday, Michigan Attorney General Bill Schuette vowed to press on with legal action to force the Army Corps to move faster.
Schuette is spearheading an ongoing lawsuit along with attorneys general from Wisconsin, Ohio, Minnesota and Pennsylvania.
“This ecological disaster has been building and building for years, with no definitive action,” Schuette said. “We need to permanently separate these two bodies of water as soon as possible.”
In 2008 President Barack Obama campaigned with a “zero tolerance” pledge for new species invasions in the Great Lakes, though the administration has gone to court to fight demands that it do more to stop two species of fish that some biologists fear could have devastating ecological and economic consequences for the Great Lakes region.
The administration maintains it is doing everything within reason to try to stop the advance of the fish, and notes it has set aside some $50 million this year alone in the battle, much of it going toward increased monitoring of the fish, research into how to control their spread and the development of a more robust electric barrier system on the Chicago canal.