Posted on 03/05/2017 9:05:27 PM PST by Leaning Right
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.)
Sterile Grass Carp are placed in some ponds by some state fisheries management personnel, to this day, for vegetation control.
The Grass Carp I ate was far less bony than the Silver Carp, but in comparison, I thought the silver carp tasted a bit better, once I got past the bones. The Grass Carp wasn’t bad, though...
Of course, this might vary greatly with water quality.
That consideration is among factors making me want to fish for those Asian carp using a roundhaul net that circles and then closes immediately, keeping most everything in the net alive ----one reason being so that game-fish species could be sorted from Asian carp, and returned to the waters the game-fish came from -- if removed from the water, at all.
My apologies for back-tracking to fisheries considerations, but there's a bit more along those lines...
Gillnets are species selective only in mesh size, and in just where and when they are set --including what parts of the water column the entangling meshes of gill, and/or trammel nets are placed in. Once a fish is caught in a gillnet, it doesn't necessarily die right away, but after some time does usually die, with this varying depending upon the type of fish, and just how gilled, or 'wedged' into the mesh, and how long the fish is in the net, etc. The fish that get away, or else those thus caught but chosen to be put back in the water -- can still suffer some amount of injury, which can lead to death, or lesser dysfunction later on. Sorry again to go on about commercial fishing aspects, when you were talking about eradication through blockage and chemical-like treatments...
As for the electric fence contemplations; I think I see better what you were intending regarding an overall plan, but the "fences" that are there presently being used did cost a pretty penny, which is something to consider The power consuptions of those things are rather high, and there's always risk that things could go haywire (leading to serious injury and death of human beings) given enough time such systems were in place.
The additional note you provided there at the end would bear more investigation;
How to make "a dam" that is usually "open"? I'm having trouble envisioning such a creature unless there be some side-sluice (or multiples of those) which could be closed off. One question, touched upon diagonally in your added "(note...)" -- what kinds of river flow does the Illinois require? That does vary, and quite a bit, too, depending upon weather conditions and need for sufficient drainage at any one time.
I must admit I don't know enough about the physics of the river systems to comment any further than idle speculation...
The sterilized fish are expensive.
I came across an article a while back that alleged there were more than a few carp which had not been successfully neutered, but sold under permit as if they had been neutered. It was a smallish scandal...
Interesting. Thanks for the info.
Sounds like a Northern edge of sorts in regards to where the Africanized colonies have been found (found more than once, I take it) at that longitude.
Of course they are. The Aficanization began in South America with Apis mellifera scutellata, which is a hot-weather, low-country Central African honeybee being deliberately crossed with relatively tamer European honeybees (Apis mellifera), though I do not at the moment recall if it the cross was with Apis mellifera lingustica , which also identified as Italian sometimes called 'Ligurian", or if it was Apis mellifera carnica aka Carniolan, aka Carnies (which are my own preferred strain of honeybee --the more pure Carny-- the better, generally speaking).
From what I've been able to glean (sifting through piles of commentary) the africanized types are not always super "hot", but can be that way -- or turn that way.
Finding a hive in the ground such as you say you did, is itself a sign that the bees were likely to be africanized. The scutellata bees, unlike European honeybees, appear to have fondness for taking up residence under the surface of the ground when conditions are favorable. European bees will do that only as last ditch effort, or so I've seen it written about by those in the know.
That's the Great White Hope. Dilute the genome, baby, dilute.
Makes a guy think (more than) twice about any effort to diminish numbers of drones within otherwise perfectly good and productive, workable (relatively tame) colonies. Even as to hive set-up, including artificial foundation or any kind, either old fashioned wax foundation, or the modern plastic that all of which, by default, are designed to maximize worker bee sized cells. Drone cells are noticeably larger. And yes, I know, there is such a a thing as "drone comb" foundation, in wax, and in plastic too -- but that's not what I'm alluding to.
Most of the uses I have seen for the sterilized grass carp seem to be in the range of 5-12 per acre of water. If their fishing is prohibited, and they get “big”, even that many will eat most of the vegetation in a pond — sometimes too much. In one of our local (state managed) ponds I think they actually need to take some out, because the pond has gone from too much vegetation to not enough...
BTW, as far as the taste goes, the grass carp pieces came from a bigger fish and I don’t know if the source (body of water) was the same for both. Plus there’s also personal preference: Some people really like crappie, but no one in my family ever acquired a taste for ‘em. At any rate, neither the silver carp or the grass carp tasted muddy or overly “fishy” to me. :-)
Eh, basically the dam would have a big gate in the middle, with the river flowing through it, as well as river traffic. The gate is only closed when a fish kill is needed.
This is not a tall dam — I’d envision maximum lake level at only the normal “flood level” of the river presently, in an average spring. It is also not there to physically block the carp: It’s purpose is to make killing all the fish in the river for the next 50 miles or so upstream practical, without severely affecting aquatic life downstream from that point. Flood control might be a secondary consideration.
Of course, the practicality of the dam also depends on what the value is of the downstream fishery, if there is still one. I’d add that rather than building the dam, it might be cheaper to dump in Potassium Permanganate at the point of the proposed dam, to deactivate the Rotenone as it goes downstream. This especially if “kills” are rarely needed.
Cost of the overall plan should be pretty modest compared to the ongoing value of the Great Lakes fisheries (including the sport fisheries.)
“Flow” is a good question and would need research.
BTE, no need to apologize for the “fisheries” thoughts. ‘Tis interesting. :-)
I think what I sampled on a few occasions has been bighead Asian carp.
It was mild, white flesh fish. Acceptable, possibly desirous depending upon how prepared. Eating it when still hot (but not too hot) makes it better. If too hot -- increased danger of not being able to separate out bones from flesh, once chewing.
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