Researchers question capability of electrical barriers blocking Asian carp entry into Lake Michigan

Oct 31, 2017

Asian carp
Credit flickr.com

A scientific manuscript soon to be published in the Journal of Great Lakes Research questions the effectiveness of the Chicago Sanitary and Ship Canal’s electrical barrier preventing Asian carp from entering Lake Michigan.

WGVU spoke with Dr. Alan Steinman about the findings. Steinman is Director of the Annis Water Resources Institute at Grand Valley State University.

“This paper deals with what happens in the area as these barges go through they’re being pulled by tugs, or pushed by tugs depending on the conditions, and between the barges and the tugs they’re actually a hydrologic ‘dead zone’ where there’s very little flow and the voltage does not penetrate into this so-called dead zone. And the fish will aggregate in these areas and so when the tugs pass through the fish, in this case the Gizzard Shad, that are hanging out in this space are able to penetrate through the electrical barrier despite being in play. In addition, as these tugs come through they cause reverse flow. That reverse flow can actually push some of these fish through the barrier due to the hydrologic movement associated with the tug moving. So based on these very discrete visual displays which the biologists were able to see, it’s clear that some fish, in this case the small Gizzard Shads, were able to penetrate through the barrier even though it was in operation.

I asked Dr. Steinman what this leads him to believe when it comes to invasive Asian carp and other fish?

“Well I suspect, and the implications of the study are, juvenile carp, the very small ones, could possibly hang out as well assuming that eventually they swim up to the barrier and penetrate through that way. So, what it means is basically the Army Corps of Engineers is going to have to come up with some different operations in order to avoid these fish from penetrating through. Now, some of that might be the water jets that we’ve talked about with the Brandon Road study so that as these tugs come through these water jests will displace this dead zone in theory, and move any of the fish out of there or, possibly increasing the voltage to the point where even the smaller fish that are trying to get out into these hydrologic dead zones might also be repulsed because the voltage is high enough to penetrate into that area. And studies need to be done to figure out what is the best mechanism to prevent this but we can’t operate on the assumption that these electrical barriers are going to be foolproof given these kinds of data.”

Patrick Center, WGVU News.