Google says that gizzard shad are very susceptible to rotenone at a much lower concentration which would allow selective action. The dose needed to kill gizzard shad is 1/10th of the dose that would kill other panfish and bass. To achieve this the amount of water in the pond would have to be relatively constant and the cost would be high to get 17 acres treated. But at least your target amount needed would be 1/10th of what is used when rotenone is used to target all the fish in the pond.
However, I am hopeful that we also cannot grow Texas-sized gizzard shad.
You do have a mature lake with large LMB. IF you have gizzard shad now, and no outside fisherman recently to introduce GSD, then I suspect you have had gizzard shad for quite some time. Your LMB may have been controlling them for a long time, and they may even be the preferred food of your largest bass.
(Of course, I am a "glass 1/2 full" kind of guy.)
Here is a link to an article (abstract) about the difficulties that GSD populations face in Kansas Reservoirs
If your GSD population does get out of control, here is an on-point article (abstract) for you.
A flood introduced Gizzard Shad into Montgomery State Fishing Lake in 2007. They did thrive in that lake, so they decided to attempt to kill them in 2013. (That lake is 105 acres and 30 feet deep. Located two counties east of you.)
They did draw down the water and treat with rotenone as canyoncreek suggested.
The treatment did get most of the Gizzard Shad, but the long-term effects on the LMB/BG were difficult to quantify. (So many other variables in the real world.)
I kind of agree with Rod that you may have had gizzard shad all along, but then again, I'm assuming you've owned your pond for more than 7 years (joined PB in 2017).
That would be surprising that you never saw them before.
I also agree that your LMB may be keeping the gizzard shad in check.
Excerpt from Robert Crais' "The Monkey's Raincoat:" "She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."
Fished the pond for 25+ years, have lived on it for 10... and it wouldn't surprise me at all if I hadn't noticed them. I've known we have Golden Shiners forever, I could easily mistake one for the other in open water.
This was the first year that crappie fishing sucked. Any known connection between GS and crappie fishing? Even though it's likely I could miss seeing these guys, I did grow up fishing waters that had GS in them and am quick to recognize a school of jumping shad or a stunned one floating toward the bank.
I fished a lot in your area of the state when I was much younger.
Whenever we crossed a lake in the evening with calm waters, we would almost always see "shad" jumping in front of the boat.
These splashes were ALWAYS small. (I would estimate a fish size equivalent to a FHM, or just a little larger.) We never saw anything splash anywhere close to the size of the large (or even medium) Gizzard Shad that are shown in those threads.
Don't know if what my father called "shad" were truly shad? I was certainly never able to catch and sample those fish in my entire life.
Sometimes after we crossed the lake, we would see the exact same size jumps and splashes adjacent to structure near the bank. Frequently, there would also be a big swirl, and we would say the "bass are chasing the shad". We loved catching bass throwing a lure into those swirls.
Is that similar to your experiences on your small lake?
If so, can any of the Kansas experts (or other experts) explain what type of fish we were most likely observing?
As regards your large crappie population declining; I have fished several watershed lakes where we would sometimes have an excellent crappie day and catch several crappie up to 16" and a whole stringer of 13-14" crappie to fillet. However, we never had a lake that would produce like that consistently. Our best crappie lakes always seemed to cycle up and then down.
Is there is a chance that we caught enough crappie on our best trips to dent the population of large crappie? My cousin's watershed lake up near Eureka was one of our good ones, and that one is usually about 35 surface acres.
My (non-expert) opinion is that you will probably get a big crappie spawn one of these springs, and 3-4 years later will once again have a nice population of large crappie in your lake. If in Year 2, you have thousands of stunted crappie, then you are going to have to cull a lot, to once again hit your large crappie goal.
P.S. My father once brought home a huge white crappie from the lake I described above. It weighed 3-1/4# at home. He said he caught it first thing in the morning, so it might have weighed 3-1/2# when caught. All of the rest of the "large" crappie we caught in that lake were right at 2 to 2-1/4#. Nothing else ever came close to the biggest crappie. I don't understand how that happens in a presumably "bell curve" population for crappie weights. I suspect some fish are just genetic or endocrinological freaks.
Yes FishinRod, I've always seen little fish jump as they get chased up into the shallows. Always thought they were native minnows or Golden Shiners. In the waters I fished growing up the shad jumping was normally not in the shallows near bank, but further out. Since there was a pattern difference I never really thought to associate them together. But maybe?
Crappie populations fluctuating is a possibility due to (I'm guessing) many things. Could be due to low water levels, introduction of shad, change in predator and forage numbers, etc. I just had noticed earlier in the summer that we were having problems catching crappie and it hasn't changed. Been a mystery so when I found those shad I thought maybe they were the cause. I really don't know.
ewest - I don't have a positive ID. I posted pics on another thread. I think they look gizzard-ish, but once again I'm unsure.
Just read in your "Shad id?" thread that your fish might be threadfin shad!
The little splashes (mainly in the open water) that I have seen all my life in Kansas ponds and watershed lakes, certainly match the size of the splashes that I saw on my last trip to Lake Texoma where the threadfin shad are abundant.
If never introduced as forage, or used as bait, TFS can only be in these small lakes due to being originally present in the stream/creek that is the water source for the lake. (Or someone upstream has introduced them into their pond.) However, theoretically the TFS should have trouble surviving in Kansas watershed lakes.
Your watershed lake is old. The one I fished the most is old. None of the other ones I have fished were new.
I would think that over the entire life of the lake, there would have been at least ONE very cold winter that extirpated the TFS. However, I have seen the same "shad" splashes in every watershed lake that I have fished in eastern Kansas.
I definitely have something wrong on this topic!
Don't know if I am wrong about the source of the splashes? Don't know if some "creek" TFS have much greater cold tolerance than we expect?
I am trying to give you more advice, but I seem to just be creating more questions!
FishinRod, having grown up with gizzard shad I'm pretty familiar with them and their sign. Up until this point I'd never seen anything in the ponds that I fish that indicate them. I've seen the small splashing that you describe my whole life and it doesn't match what I see when I'm on a place that has gizzard shad. Not saying you're wrong, just saying that a lifetime of fishing south central KS ponds and watersheds haven't produced the same shad sign that fishing the Arkansas river, the Walnut, and reservoirs has produced.
Our watershed froze over last winter, as well as what was left of the creek that feeds it, and the small ponds upstream. Everything was low or dry due to drought. I'm not seeing conditions that I think threadfin could survive in.
I've watched the video posted on the other thread several times and keep coming up with gizzard shad. If it wasn't for a huge amount of respect for ewest and his opinion I wouldn't be questioning myself on the id.
FWIW, Threadfin shad will not survive in water that freezes over unless it is deep and they have a warmer water place to go, like a power generating cooling pond. My vote is Gizzard.
Back to the original question... ASSUMING they are gizzard shad how do I move forward? I spent the summer removing bass (goal of 20lbs/acre). If I have gizzard shad would that have unintended consequences? Would it give shad the opportunity to over populate and end up dominating the biomass of the pond? Or am I still on the right track going forward with a yearly goal of removing bass?
Back to the original question... ASSUMING they are gizzard shad how do I move forward? I spent the summer removing bass (goal of 20lbs/acre). If I have gizzard shad would that have unintended consequences? Would it give shad the opportunity to over populate and end up dominating the biomass of the pond? Or am I still on the right track going forward with a yearly goal of removing bass?
In a Northern pond, Gizzard shad WILL overpopulate no matter what you do, that is if shad management methods aren't implemented. The shad will grow too large for the bass to eat in less than two years. In a 19 ac BOW, nothing is cheap. The state here in Indiana, in larger public bodies of water will do a low dose of rotenone to kill most of the gizzard shad but not any of the other fish. If it was my pond, I'd start a feeding program for the BG to bump their population and fecundity, then I'd do a low dose rotenone treatment and follow up after that treatment in a month with a whole lake electroshock survey, even the open waters to monitor the shad population. While some shad are OK, getting too many will skew the fish biomass. Then 2 years down the road I'd do another electroshock survey to check the GSD population and LMB population. If GSD population is rebounding from when the first survey was done, I'd schedule a low dose rotenone treatment for that year and the next two consecutive years. THEN schedule another electroshock survey to monitor the fish population after those 3 treatments. I would schedule the treatments for late June to allow the treatments to target any YOY GSD that were hatched the prior 60 days vs. letting them grow larger and most likely spawn the following year.
For an example a local 365 acre lake had Gizzards introduced years ago. (the whole lake was rotenoned by the state in the late 1960's due to a carp/gar overpopulation). When the DNR did a gill net survey some years ago they found that over 60% of the fish biomass in the lake was Gizzard Shad. Maybe due to the gill net size, but the majority of the shad caught were too big to be utilized by the LMB for food.
Some other impoundments in the state that have a Gizzard Shad problem were stocked with Stripers, NOT HSB.
Oops, I forgot the LMB question. I'd continue to remove the LMB, but go according to RW. Remove the same poundage per surface acre (20#) but only LMB that were below 90%. If post spawn, I'd drop that RW figure to 80%-85% depending on how the LMB looked. i.e. a post spawn female will have shoulders but have a low RW. Once you catch enough LMB you will be able to tell if it's a cull or a return to the BOW.
Last edited by esshup; 10/23/2411:11 AM. Reason: LMB info
Back to the original question... ASSUMING they are gizzard shad how do I move forward? I spent the summer removing bass (goal of 20lbs/acre). If I have gizzard shad would that have unintended consequences? Would it give shad the opportunity to over populate and end up dominating the biomass of the pond? Or am I still on the right track going forward with a yearly goal of removing bass?
In a Northern pond, Gizzard shad WILL overpopulate no matter what you do, that is if shad management methods aren't implemented. The shad will grow too large for the bass to eat in less than two years. In a 19 ac BOW, nothing is cheap. The state here in Indiana, in larger public bodies of water will do a low dose of rotenone to kill most of the gizzard shad but not any of the other fish. If it was my pond, I'd start a feeding program for the BG to bump their population and fecundity, then I'd do a low dose rotenone treatment and follow up after that treatment in a month with a whole lake electroshock survey, even the open waters to monitor the shad population. While some shad are OK, getting too many will skew the fish biomass. Then 2 years down the road I'd do another electroshock survey to check the GSD population and LMB population. If GSD population is rebounding from when the first survey was done, I'd schedule a low dose rotenone treatment for that year and the next two consecutive years. THEN schedule another electroshock survey to monitor the fish population after those 3 treatments. I would schedule the treatments for late June to allow the treatments to target any YOY GSD that were hatched the prior 60 days vs. letting them grow larger and most likely spawn the following year.
For an example a local 365 acre lake had Gizzards introduced years ago. (the whole lake was rotenoned by the state in the late 1960's due to a carp/gar overpopulation). When the DNR did a gill net survey some years ago they found that over 60% of the fish biomass in the lake was Gizzard Shad. Maybe due to the gill net size, but the majority of the shad caught were too big to be utilized by the LMB for food.
Some other impoundments in the state that have a Gizzard Shad problem were stocked with Stripers, NOT HSB.
Oops, I forgot the LMB question. I'd continue to remove the LMB, but go according to RW. Remove the same poundage per surface acre (20#) but only LMB that were below 90%. If post spawn, I'd drop that RW figure to 80%-85% depending on how the LMB looked. i.e. a post spawn female will have shoulders but have a low RW. Once you catch enough LMB you will be able to tell if it's a cull or a return to the BOW.
Now that is an answer! Thank you for being so complete and straight-forward! You've given me a lot to consider.
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