Pond Boss
Posted By: Spicelanebass Gizzard Shad Rule!! - 06/26/15 05:08 PM
Would like some opinions on this article.............

http://www.bassresource.com/fish_biology/gizzard_shad.html
Posted By: fishm_n Re: Gizzard Shad Rule!! - 06/26/15 05:42 PM
I don't think it mentioned dangers of too small a pond or no having a lmb pop established yet. Still a fun read.
Posted By: sprkplug Re: Gizzard Shad Rule!! - 06/26/15 06:00 PM
Here you go. Right home, here in Indiana.

http://www.washtimesherald.com/news/loca...388106b233.html
Posted By: Snakebite Re: Gizzard Shad Rule!! - 06/26/15 06:14 PM
Thanks for the share sprkplug, I haven't come across reading where the GSHD had caused a BG population that caused the problem, rather than direct effect of the shad.

I also think the structure of a lake has lots to do with weather GSHD are a good option. They prefer open water swimming so you would need ambush points out in open water for bass to have a better crack at them.
Posted By: Bill Cody Re: Gizzard Shad Rule!! - 06/26/15 06:51 PM
Here are my comments regarding the gizzard shad article.
1. the author mentions 3 things are important for growing trophy bass: age, genetics, and nutrition. His quote "...key factors for producing trophy bass are well known: age, genetics and nutrition". He neglects one additional important feature HABITAT. I wonder what other things does he omit to make his case.
2. the author ignores carrying capacity and the pond's productivity necessary to grow a limited number of trophy predators per acre.
3.He states from his MS thesis study "My research showed small bluegill rely very little on zoo plankton. Primary food of bluegill, I found, are aquatic insects which live on, and in, the pond bottom." My first question was large sized zooplankton present in his research ponds for BG to utilize as food? Zooplankton are delicate organisms and do not retain recognizable shape very long in a fish's stomach. Most zooplankton that reach the stomach appear as 'mush' or ooze. What were his methods to recognize zooplankton in gut contents?? Whereas midge larvae have relatively thick durable chitinous head capsules which digest and degrade very slowly. Midge head capsules are used in bottom sediment cores for historical studies of lakes. My question is were the zooplankton mushy remains present and unrecognizable and the only gut contents recognizable were midge head capsules? BG may have been eating lots of zooplankton in his study, he could not recognize them from organic 'mush'. He may have ignored this 'can of worms' in his thesis.
4. Keep in mind that he stresses that fertilization is necessary for producing good shad populations. Proper fertilization to get a good consistent bloom is art and science. Professionals often have difficulty getting a good bloom and maintaining it in some ponds/lakes. Fertilization and bloom are necessary with g.shad to keep the shad from competing with the other fish that rely on plankton or the food it ultimately produces.
5. He does not mention that when plankton is limiting that g.shad resort to rooting in the sediments for food causing turbidity issues in the pond/lake. Turbidity can reduce the growth rate of all sight feeding fish including BG and bass. It is difficult to grow trophy bass in a pond/lake with excessive turbidity because the bass cannot adequately find prey fish. Thus the potential for growing trophy bass becomes diminished and a desire not a reality. This topic comes full circle back to proper HABITAT that I mentioned in the first item.

G.shad probably do have a role in producing trophy bass, but it is not just a matter of adding g.shad to a pond or lake. Numerous things have to come or fit together for the "process" to work. IMO adding g.shad to produce trophy 10 lb+ bass probably doesn't work well more times than it is successful. There are at least a few reservoirs near me that have g.shad and no trophy bass come out of those reservoirs.
Posted By: fishm_n Re: Gizzard Shad Rule!! - 06/26/15 07:14 PM
Thanks bill!
Posted By: teehjaeh57 Re: Gizzard Shad Rule!! - 06/26/15 07:27 PM
That's a classic Bill Cody response - appreciate you illuminating the facts omitted from this article. Solid gold, as usual.
Posted By: esshup Re: Gizzard Shad Rule!! - 06/27/15 12:50 PM
Listen to what Bill wrote. Read it as many times as needed to understand EVERYTHING that he's saying. In waters where the majority of LMB aren't over 22"-24" what he said in his last paragraph is what I've observed too.

Up here, I've seen g. shad cause more problems than solutions.
Posted By: ewest Re: Gizzard Shad Rule!! - 06/29/15 08:09 PM
Here is some Gizzard info from prior posts. The last few links are broken -- can anyone fix them ?

Lets not confuse things. TShad are an entirely different situation. I asked Bob about that quote under GShad and IIRC he was using shad generically. I suggest that Bob answer - I think I can find his reply on the forum.

I completely agree with Bill's post. I have seen very good trophy LMB ponds with no shad. It takes mgt but can be done without shad. A fair % of people use TShad and a few GShad. IMO you can get the same results with TShad without the various GShad problems and still keep a good BG population.

IMO starting a southern pond (including OK) by stocking with GShad as part of the initial stocking of small fish (2-3 inch stockers)is a serious mistake. Using them later as noted above may work but you have to understand what you are doing.

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OK guys lets discuss this. First the link by Aaron to the PB thread by Bill is newer than the other link to a K. Nutt article in PB. IMO there is just as much or more info against GShad in most instances as he cites for using them in limited circumstances. Mr Nutt established SEP and is an excellent FS. He has his opinions as do others. I will not do a point by point analysis of the points I disagree with. You can read his article and the PB thread. There is subsequent research as well. I suggest you read the stuff below off the SEP web site which is what they suggest now. There are IMO differences in his first article and the newer info below. I think the info below is well done. Like all general recommendations they have to be applied to location specific circumstances as they note. Highlights in blue by me.

http://www.sepond.com/GZS.html


Gizzard shad (Dorsoma cepedianum) also are a member of the herring family - Clupeidae. They occur in many rivers and reservoirs across the southeast and are occasionally stocked in ponds managed for trophy largemouth bass. Adult gizzard shad are substantially larger than threadfin shad, often reaching lengths in excess of 12 inches in fertile waters. Juvenile gizzard shad can resemble threadfin shad in coloration. However, gizzard shad have a subterminal mouth with the upper jaw extending well past the lower jaw. Also, the upper jaw has a well-defined notch in the center. Gizzard shad are pelagic filter feeders, feeding primarily on plankton, algae, and suspended organic material. However, they will often "graze" on the bottom, feeding on aquatic insects and organic sediment. Gizzard shad begin spawning about the same time as threadfin shad; however, reproduction during the latter part of the growing season is less evident. Also, gizzard shad are much more tolerant of low temperature than threadfin shad and not as susceptible to winter mortality.Gizzard Shad in Sport Fish Ponds
In certain situations, and if managed correctly, gizzard shad can be an ideal supplemental forage for producing exceptionally large bass. Trophy bass require large food items, measuring 6 to 10 inches in length to continue to grow. Gizzard shad quickly grow to 6 and 7 inches long and will achieve a larger adult size than threadfin shad, thus providing the larger bass with a more efficient prey item. They may also serve as an alternative to threadfin shad as an additional forage base in ponds located in colder climates.
Drawbacks
When stocked into a bass/bluegill pond, their large potential size and rapid growth rate often allow gizzard shad to "stockpile" at a size too large to be consumed by the bass. Over time, they can occupy a large portion of the total fish biomass within the pond. Gizzard shad reproduction eventually will decrease in response to over-crowding, resulting in little forage for the average size bass in the population. To avoid this situation, it is usually necessary to remove a portion of the gizzard shad population every 3 to 5 years with rotenone. Maintaining a healthy, reproducing population is the key to managing gizzard shad in sport fish ponds.
Pond RequirementsThe requirements of gizzard shad in ponds are similar to threadfin shad. However, gizzard shad have a much broader range of water temperature and water quality in which they can live. Introducing gizzard shad with threadfin shad creates a more natural environment for each species by providing a healthy competition for the available food. We have found that the period gizzard shad continue reproducing is often extended in ponds that also have an established threadfin shad population. Therefore, the amount of time between corrective rotenone treatments can be extended. When stocked together, threadfin shad will be especially beneficial to the growth of smaller bass.
When and How Many to Stock
We recommend stocking gizzard shad in trophy bass ponds when they have a large number of bass over 16 inches in length in the population. They are usually stocked in the spring but can be stocked later in the growing season when available. The stocking rate may be similar to threadfin shad; however, it is usually determined individually for each pond.



http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=11348&page=1

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=73328&page=1

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=235404&page=1


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http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=11348&page=1

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=1557&Number=17531#Post17531

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=158807&page=1

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=177656&page=1

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=187704&page=1 - including Bob’s input

http://forums.pondboss.com//ubbthreads.php?ubb=showflat&Number=202827&page=1


Posted By: fish n chips Re: Gizzard Shad Rule!! - 06/29/15 09:40 PM
Here's the broken bottom ones with the correct links.


http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=11348&page=1

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=1557&Number=17531#Post17531

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=158807&page=1

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=177656&page=1

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=187704&page=1 - including Bob’s input

http://forums.pondboss.com//ubbthreads.php?ubb=showflat&Number=202827&page=1
Posted By: ewest Re: Gizzard Shad Rule!! - 07/01/15 06:57 PM
Thanks a ton fish n chips. That helps. How did you do that?
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