Separate the basins! Save the Great Lakes?

5 Jul 2011

Asian Carp and every March 17th - green dye

Tourists to Chicago are likely to hear how some 100 years ago, the State of Illinois, as an engineering marvel of the age, reversed the flow of the Chicago River (which used to flow into Lake Michigan) so that now it flows away from Lake Michigan and into Mississippi River basin (the reason for this had to do with sewage flowing into the City’s drinking water supply).  

Reportedly, every day, 2 billion gallons of water flows away from Lake Michigan which 100 years ago would flow INTO the Lake (the third largest body of fresh water in the world).  

With the latest invasive species threat, Asian carp, something Kevin blogged about recently,  a number of groups have proposed separating the Great Lakes and Mississippi basins.  But that effort picked up some serious scientific credibility and traction with the latest report from a group of scientists in a well respected journal, the Journal of Great Lakes Research.  The report, whose abstract I have read, takes on four common arguments against separating the River from the Lake: 

1. An existing electric barrier bars the carp.  The authors cite dozens of positive DNA samples taken from waters upstream of the canal as solid evidence that “the electric barriers have not been fully effective on Asian carp.”

2. Asian carp are already  in the Great Lakes so there’s nothing to be done.  The paper claims there is no compelling evidence that, despite DNA samples showing a barrier system breach, the fish have begun reproducing.

3. Even if Asian carp get into the Great Lakes, they won’t be able to thrive.  The authors argue there are places in the lakes, particularly warm, algae-rich areas including Saginaw Bay and the west end of Lake Erie, where the fish will find enough food to thrive.

4.  Even if the fish do get established, they won’t do the harm some have claimed.  The paper argues that the carp could negatively impact what’s left of the lake’s native fish species in a variety of ways.

The Army Corps of Engineers doesn’t plan to finish its ongoing study until 2015 at the earliest.  However, these scientists say more study isn’t needed (and when do scientists ever say that?) and they support proposed legislation to force the Corps to speed up the study.  In that way, everyone will know the costs and the risks and can evaluate the best way to proceed.  Certainly, the shipping industry will not like this but Michigan and just about every Great Lakes jurisdiction (except of course, Illinois) is very concerned about the decimation of the local fishing industry by this invasive species.  For once, the Courts have been unhelpful and the focus now falls on Congress.

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