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Barrier Broken? Asian carp electric barrier loses juice and exposes folly of the faux fence

Henry Henderson

Posted May 7, 2012

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Asian Carp Under Glass by jmogs via Flickr

I got a call over the weekend looking for my take on news that the electric barrier, billed as a “success” and the best tool to keep the invasive Asian carp away from Lake Michigan, had lost power, leaving the Chicago Waterways unprotected for a short time last week. My immediate reaction was:

"That's the problem with an electric fence; the electricity…[W]e see outages during the violent storms that have become more commonplace in recent years. The Corps needs to get serious about the hard work of figuring out how to install a permanent physical barrier into the system that addresses legitimate commercial concerns while finally stopping the movement of all invasive species between the Mississippi River system and Great Lakes; not just the big, bad Asian carp."

Given more time to reflect on the situation has reinforced my reaction: the status quo does not give us adequate protection.

The episode illustrates the inherent problems with the Army Corps of Engineers’ approach, which is to rely on a flawed and fallible system indefinitely while they take their time contemplating the comparative costs and benefits of multiple approaches that run from doing nothing to inventing new poisons to experimenting with music, sound guns and bubbles underwater.

The power outage underscores the dodgy nature of this virtual fence, exposing its limitations once again. Last year, the Corps had to turn up the electric juice a full 15% after realizing that the previous current was too weak to prevent small Asian carp from swimming through the “fence” and toward the Lake.

And, of course, the problem is not just about Asian Carp, but the broader issue of all the other invasive species that can move between the Great Lakes and Mississippi River system through our local waterways unaffected by electric charges, however strong. The Corps counts a full 49 species that could move through the canals and Chicago River, only some of which are kept at bay by the Corps’ current fish fence. An actual, physical barrier separating the Mississippi River Basin from the Great Lakes would address all of these issues---and as Jeanne Gang showed in her brilliant re-envisioning of the Chicago River, the separation don right could create a spectacular public amenity.

As I noted over the weekend, we are under no illusions that putting a physical barrier in the waterways is an easy task. It requires proper engineering, infrastructure coordination, community engagement and investment. But the electric outage episode this week makes clear that there is no time to mess around. We must get on to the tough work to accommodate both navigation, water management and ecosystem needs. It can be done---but we must get started, on a genuine permanent solution. Otherwise, we are dependent upon unreliable, half measures that compromise on our health, safety and economic future.


Asian Carp, Thankfully Under Glass by jmogs via Flickr

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George J.May 7 2012 10:09 PM

You are correct in pointing out that our long term strategy for dealing with invasive species should not rely on flawed and fallible systems. Unfortunately, relying on dams or land bridges to stop Asian Carp and other invasive species will be no more infallible than the electric barriers already in place in Chicago.

The list of aquatic species that have migrated past fixed land bridges and dams is as long as the history evolution itself. To understand why separating the Mississippi River and Great Lakes basins with a dam or land bridge will not stop invasive species you first have to understand that there is a difference between hydrological separation and ecological separation. The truth is that hydrological separation has never effectively stopped migration of aquatic species between ecological systems that support their existence. To see evidence of this all you have to do is ask yourself how all the lakes and waterways, including the Great Lakes, came to have such a diverse and yet shared population of aquatic species even though many are isolated by significant land bridges.

Perhaps one reason why the Army Corps is looking at multiple strategies is that, being the good soldiers that they are, they realize that fixed fortifications are of little permanent value regardless of whether you are at war with invasive species or the armies of foreign invaders. The reality is that, before they could even be completed, barriers across Chicago's waterways will have no more relevance in stopping Asian Carp and other invasive species than the old bunkers that once made up the Maginot Line across Europe had in stopping the Nazis from invading France.

With a total economic, environmental, and infrastructure cost that will certainly be in the $10s of billions, and a construction time that will most likely be over 25 years, using the 19th century barrier strategy would be a failure of biblical proportions. If we have any chance at all of resolving this issue we need to learn from what nature has shown us and from our past experiences. I think the Army Corps gets it - it's going to take a 21st century solution to address invasive species migration and now is the time to abandon what does not, and has not, worked and start to develop and implement new strategies based on science rather than shovels.

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