There's been concern that the buffalo carp, and more importantly paddlefish along with smaller species such as gizzard shad (which are feed for larger game fish and pan fish) are undergoing deleterious effects wherever carp populations are highest (and of course, naturally enough, downstream from those locales0.
Of course you know that, already. I'm simply repeating it here to further publicize the information...
Which river? The Illinois? And what's with the "downstream dam" with electric fences "along the river"? I'm not seeing how that would work --- unless what you are thinking about is trapping the carp already in Lake Barkley?
If a dam or dams were to be built on the Illinois-- why not simply shut off the Chicago Sanitary and Ship Canal (aka; Chicago Drainage Canal)? If that were to occur, if there was no dam at some point built so as to provide a spillway to ensure water flow, one big problem could be need for large pumps to transfer water from Lake Michigan to the canal downstream of the dam blockage in order to keep the upper reaches of the Illinois to Corp of Engineer's specified channel depth (9 ft.).
That would shut off whatever barge traffic there is, and possibly make the upper reaches of the Illinois left high and dry part-time during the year.
Building dams would close off the barge traffic. Unless instead of locks, there were 'dry' lifts for barges, which I guess could be costly to operate. A system such as that, where barges would be hauled out and transited on, say, a dedicated railway from water to water, would be expensive to first; build, then maintain and operate. I'm sure it's been thought of and further investigated as to costs --- so has thus far been dismissed as impracticable.
Imagine if billions of dollars were spent in some way, and waterfowl still transported carp eggs in their feathers (and stuck in their bills) to the Great Lakes regardless of all the extra, and highly expensive efforts?
Not that this will cure or fix "the problem" of Asian carp menacing the Great Lakes; but I've already been scheming upon a net design where I could wrap 'em (round haul) but without using a purse line.
I've gotten to the point where I can start counting meshes (by the stretch measure foot) to then convert those numbers into lbs. of nylon webbing (which generally runs 9$-12$ per lb, sometimes less when purchasing large amounts of factory web). But I may switch to braided web, or else even polyethylene web for the middle "sack" or bunt portion of the net -- which portion would be no bunt at all as those are known in seine net terminology, transitioning instead to a "sock" as we called that when I was fishing on a seiner in Southeast Alaska.
The sock is like the body of a miniature trawl net. Trawls I really know, having fished those for many years, and worked in net shops too, along with regular repair, rebuild, and re-hanging a variety of those when not being part of a "net shop".
The reason for using a seine (instead of the gill and trammel nets most often presently used for commercial Asian carp harvesting) is that I think I'd want to catch the fish alive, so the fish could be bled while still alive. After which; chilled/refrigerated near immediately.
Both of those steps would raise the eating quality of the fish, which in turn could (hopefully) help lead to wider acceptance of the fish among American consumers, while also fortifying what export market demands presently exist.
But all that costs money, and would be challenging to accomplish on trailerable (8' 6" width) boats, and possibly purpose-built barges. Going bigger means a person would have to go through locks when transitioning from one segment of a river to another -- and -- would led to needing offload from the boat onto a truck instead of putting a boatload of fish on a trailer and taking that to whenever it would be offloaded and sold directly to a processor, or else processed by one's own company.
Whichever way -- a guy could not be fishing full-time and processing full-time without hiring many persons to assist, which raises the question === would it pencil out (be profitable after paying wages and taxes along with each and every other expense).
If they (dang those "they" people!) would just allow me to hit the Mega for about $200 million --- I could find out if it would be profitable, or not. It would keep me out of the bingo parlors, regardless, that's for sure. :^')
I’ve seen multiple studies showing that the Asian Carp diminish the numbers of sport fish present, sometimes fairly dramatically. Again, the food chain is being eaten away from under them. Plus, even very young bass and such eat plankton, so, they are affected too.
Put more simply, a given body of water will only support so much biomass in the form of fish. If the water is full of Asian Carp, other species will be diminished, especially if many of the carp are too big for the predators to handle.
As for the dam / electric fence proposal, no, that’s not for the Tennessee or Cumberland Rivers. The carp are now well past (upstream) of KY Lake and Lake Barkley, so, the only practical solutions there will have to be in the way of commercial fishing, or biological warfare.
However, you may be reading my proposal for the Illinois River as being “bigger” than it is. To restate, and modify slightly, having had more time to think it over:
My proposal is really just an expansion of what’s already been done.
http://ens-newswire.com/2013/01/12/chicago-fish-fence-fails-to-deter-giant-asian-carp/
(The title is a misnomer — so far, the fences are helping. But they are not sufficient in themselves, and Rotenone then is applied.)
It turns out there are already two “electric fences” on the Illinois River System. (At least one is actually in the shipping canal connecting the Illinois River to the Chicago River, via the Des Plaines River and the Shipping Canal, leading to Lake Michigan.) In conjunction with the Lockport Lock and Dam, and applications of Rotenone, so far, these measures have stymied the advance of the Asian Carp toward Lake Michigan. A few carp may have made it past the fence, but, so far at least, they do not appear to be a breeding population. (If there are two male AC in Lake Michigan, and 2 female AC in Lake Michigan, the chances of any of them finding a mate to spawn with are VERY low.)
So, assuming the existing “electric fence” in the canal is a convenient starting point, place more “electric fences” downstream (ie., toward the Mississippi River), followed by a modest dam — the dam to be as far downstream from the existing “electric fences” as possible. (Note that the confluence with the Kankakee River likely limits how far south / downstream the new dam can go. But, Joliet is upstream, which may help deter birds carrying Carp eggs or Carp upstream.) Under normal circumstances, the river pretty much just flows through the new dam. It is only closed for a fish kill operation, therefor locks are not needed. The biggest problem I see is having enough water storage capacity to “back up” the river at a time of low flow, for a couple days.
Basically, the idea is to impede migration of the fish, and, if need be, have a ready made “kill zone” on hand.
(Note that since water flows from Lake Michigan into the Chicago River to the canal to the Des Plains River to the Illinois River, and IIRC the inflow can be interrupted, the concern about water storage capacity for a fish kill operation may be invalid.)