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ORIGINAL: fishpoint
Didn't Craptracker say that the Asian carp don't seem to be migrating much past the I-55 bridge over the Des Plaines? I think it is only a matter of time before one gets introduced into Lake Michigan.
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Old news. Took a while for many them to get past the Starved Rock dam, but now more abundant up there, although still uncommon. These fish don't like boats, and they don't do well at getting through navigation locks. But high water in 08 in the Mississippi River has apparently allowed them to bypass the locks and move on upstream- silvers and bigheads are now showing up in places they have never been before in the Upper Mississippi River. I believe that under the right conditions, when moving upstream in the spawning season, these fish can probably do at least 20 and probably 50 miles upstream in a day. The Ship and Sanitary Canal is not great Asian carp habitat, at least for living and eating. Asian carp pick entirely different habitats for living and eating than they do for spawning. During high water events, they are attracted to areas of high current and turbulence, and they will move long distances to reach those areas. That means they won't hang out in the canal, butno one knows if they will try to make the run up it during a high water event. That also means that we don't really know if the existing electrical barrier has ever been challenged by an Asian carp. It could have been challenged dozens of times during high water events (the only time it is likely to be challenged) and we would never know. We can't effectively go out and sample at those times. It also means that a power outage at the wrong time could be disasterous - the fish certainly have the capability of swimming upstream from where they have been spotted now to above the barrier and probably all the way to Lake Michigan in a single day.
The more fish show up farther up the river (and it appears to be that more fish are getting up there all the time), the more likely it is that some of them will try to make the run up the canal.
Really bad news: Duringveryhigh water events (but we are NOT talking 100 year floods - just very water that occurs on a semi-regular basis) there is probably opportunity for fish to move between the Ship and Sanitary Canal and the Des Plaines River through low spots and ditches that are normally dry but laterally connect the Canal to the Des Plaines during high water. These connections go through ABOVE the barrier. So if fish go through the ditches they will bypass the barrier. In my personal opinion, it is more likely that juvenile fish would make it through these shallow connections than adult fish (although I'm not ruling out larger fish getting through those connections). We have not seen any juvies that high up the Des Plaines yet, but spring is coming. It is urgent that these low spots be blocked. They are not hydrologically required to be connected. It is a matter of moving some dirt. And it is time to get on with it.
If the carp do make it into the Great Lakes, it is possible that it won't be a catastrophe. Or it may just be a localized catastrophe, where the carp only take up residence in numbers in places like Green Bay, where there would be substantial planktonic resources. Or they may just get out-competed by the zebra and quagga mussels. But my personal guess, and it is nothing more than that, is that they will take 20 or 30 years to reach high enough population density that people start noticing them a lot, and then things will get out of hand rapidly. That's where my money is. But treat that information like you would a prognositicator on the Super Bowl - an educated guess.
Carp Barrier Still not working
