Pond Boss Forums STOCKING A NEW POND Raising Forage and Bait A good source for threadfin shad?

Any suggestions on where I can purchase quality threadfin shad? Have any of you had luck raising thread fins in a forage pond before stocking them? I have found places that sell gizzard shad but I have heard many stories of gizzard shad growing too large to be eaten and over populating lakes.

Any thoughts?

I would think that in Florida you could have bass large enough to eat gizzard shad. I would think that a seven or eight pound bass could handle a one pound gizzard shad? When I went fishing on Stick Marsh we used live shiners that were about a pound.

So you would suggest gizzard shad instead of threadfins? I have been reading up on threadfins and apparently they are hard to transport and establish. Can gizzard shad be stocked in less fertile waters?

The thing is I have not been able to find anyone who will deliver threadfins to florida. The closest place I have found is based out of alabama. They didnt want to risk transporting the threadfins for more than three hours on the road.

GTS, how far down in FLA are you? Greg Grimes might cover the upper part and I think he does threadfin stocking. Seasonally, of course.

I'm in hillsborough county about 15 miles east of Tampa.

Do you think I would have a better chance of establishing golden shiners, threadfin shad or gizzard shad in an 8 acre pond that has a relatively young bass population? I have bluegill and red ear stocked as forage but I feel that the bass are putting quite a strain on them.

Not GShad in a pond with young LMB. You need to have 25-30 % of your LMB over 18 inches at a minimum to even consider them. Many studies show a very high % of a pond's carrying capacity used up in GShad to the detriment of all other species.

Find TShad and or GShiners to establish.

if I end up deliverying for client in orlando we could help with del cost. Only spring of course so let us know if interested. thanks

If you do go with the threadfins, stock them in the spring like Greg said. The idea is to stock them just before they spawn. With a young bass population, they should establish easily. You are far enough south you also don't have to worry about winter kills with threadfins.

With golden shiners(GSH), if you have a young bass population, stock 5 pounds per acre of larger adult GSH. Say, fish 5-6" plus in size. At that size, they should mostly avoid predation by your new bass and will pull of a spawn. I think GSH would also be a good addition to your pond if you are trying to grow larger bass...

personally i think you should go with both Golden Shiners and Threadfin Shad. You COULD have Gizzards but i would only use it on a pond with some monster bass, im talking a pond 5+ years old with some big fish or if your goign to have people electrofish it yearly. Bluegill and Readear sunfish wont sustain a bass population for that long so i would add
Golden Shiners
Threadfin Shad
Fathead Minnows
Crawfish

Gizzard shad grow significantly bigger than one pound. I saw a photo of one online recently that looked like it was at least seventeen inches and three pounds. Here's an article that says they grow up to 18", and that stripers were originally stocked into inland reservoirs to control the gizzard shad the LMB couldn't eat:

http://www.insideline.net/1999/price-0910-99.html

I would be wary of them. But the flip side is, they have been used successfully by some prominent Southern pond management companies to grow very large LMB.

Walt a 21" gizzard on Ray Scotts lake few years ago. Here is a few pics on our shad page. http://lakework.com/photo_gallery/gallery2/v/Fish+ID/Shad/
I think there a near neccesity to produce good numbers of bass over 10 lbs. They come with many issues and talk most out of stocking but in the right situation (as Ewest stated) with proper goals they grow some giant bass.

Here are some GShad.

Yikes it would take one HUGE bass to eat that Gshad!

Greg some of the baits we were using on stick marsh were about the size of the gizzard shad in your album. Eric is right it takes a very large bass to eat something that big but how are you going to raise a monster bass on fatheads. I would not consider stocking gizzard shad unless you have some fairly large bass already or you will end up with a mess and you maight end up with a pond of gizzard shad anyway. I didn't stock shad in my pond but ended up with both gizzard and threadfin after a flood we had two years ago. So the question is do you risk making a mess in order to try to grow trophy bass? I think some of us on the forum would take the risk knowing the possible outcome but weigh what Eric is saying carefully. threadfins are a safer choice without the risks.

It has been said that gshad have an adverse affect on the growth of young bluegill because the shad consume zooplankton also. Is this true? Threadfins eat plankton also, but since they are small I guess that have less affect on the bluegill population? How much do golden shiners compete with bluegill?

I would think if their total biomass was equal, Gizzards and Threadfin would consume about the same amount of plankton.

Threadfins and gizzard both are the worst thing you could ever do to a pond if you care about big bluegill at all. They're great for growing big bass, but to answer your question, GTS, they most definitely eat plankton, like it was going out of style. I'm working with a 56-acre lake right now that has small bluegill (average 5" or so); one of the first things the owner told me the first time we talked was that his lake used to have "huge" bluegill but that he didn't know what had happened to them but they were a fraction of the size they used to be. He had mentioned that he had stocked threadfin and gizzard four or five years ago, so I asked him if that was about the time his bluegill started declining, and he said, "Oh yeah, come to think of it, it was." He likes catching big bass but also is an avid bluegill angler; the people who managed the lake previously had just not asked enough questions, or else had not listened too closely to his answers.

As to GSH, they too most definitely compete with bluegill for food. There's a lake around 150 acres near my hometown that years ago, before TWRA took it over, produced bluegill approaching three pounds - I've seen two of them mounted, just beasts. So TWRA stocked GSH in the lake, and now it's overrun with them, and the bluegill are a fraction of the size they once were. I fished it once this spring, fished several different spots all around the lake, and I couldn't even get my bait to the bluegill because it was being taken almost every cast, everywhere I fished, by 8" GSH. The few bluegill I caught were small, under 6". I haven't been back since. There are a few big LMB in the lake now but the GSH have ruined the bluegill fishing.

I've never seen a lake where threadfin, gizzard, or GSH were stocked that the bluegill average size didn't plummet.

Normally I only feed the bluegill during the winter months(what passes for winter here), but I was about to start feeding regurlarly anyway. Would the feedings offset any negative effects on the bluegill? I know that gizzard shad will eat the feed, so I guess they are completely out of the question. That said would shiners or threadfins fit better?

I would stock shiners because they are natural and grow great in your location. TShad will work but they require a plankton bloom and may effect your BG size unless properly managed. You also have the option of tilapia as they occur all around your location but they could effect the BG as well.

Which fish is your top priority, GTS? If it's LMB, you'll get bigger LMB by stocking GSH than you would have otherwise, and adding threadfin to the mix will help the bass even more. But if bluegill are your top priority, GSH or threadfin either one will cut at least in half your maximum bluegill size, as well as your average. It's a pretty simple equation - a large percentage of their diet is comprised of the same foods that bluegill eat:

http://en.wikipedia.org/wiki/Golden_shiner

So they will directly compete with bluegill for food, and that only ends one way, with smaller bluegill. If bass are your primary focus, GSH and threadfin both will help you to achieve bigger ones; if bluegill are top priority, GSH and threadfin will make it almost impossible to achieve trophy bluegill. Feeding won't even close to make up the difference. You'll get decent-sized bluegill - a few - but you won't get trophy-class fish. The lake I mention above in which the bluegill size was killed by the addition of threadfins, has had an automatic feeder on it for five years, and the bluegill are slightly larger than they are in the rest of the lake, but they still only average 5-6" though the feeder goes off twice a day with Aquamax food.

It really depends on your pond/lake. Its productivity will be key. So it all depends. Walt could be right as to what he experienced but it may be different with your situation. I have seen lakes in central Fla with carrying capacity of 2500-3000 lbs per acre loaded with big fish including both shads , CNBG , shiners and tilapia all mixed together. I have also seen lakes that are lucky to have 100 lbs of fish per acre.

Walt are these lakes fertile or do you think that makes a difference? Is there not anything that can control the gizzard shad if they start to take over? Can hybrid striped bass grow large enough to make a difference since gizzard shad and hybrids tend to patrol the same waters? Walt I don't know where you rate catfish but I would tell people to be careful about stocking catfish. I was told that they would not reproduce and their numbers could be easily controled but that has not been my experience. They seem to outcompete everything at the feeder.

Walt, the logic of reduced growth in BG from competition from TFS and GSH eating the same thing makes sense to me. But, what I question is the severity of the reduction in growth. I'll preface the rest with the fact that I have NO experience with any of it, but am contemplating introducing TFS and GSH into my 5 acre pond next spring. I understand your experience suggests significantly lower growth rates and I appreciate your covering this topic. I've not read or seen any studies relating to the competition, but would think there should be something out there as this is seems to me to be a very important topic..What I think I hear from you is that it is very, very difficult to get large( a relative term, but let's say 8-10lb) bass and large (8-10") BG in the same pond. Is Talapia,where they are legal, then the best alternative to providing additional forage for bass growth??? Again, I don't in anyway dispute what you are saying, but further clarification would help me make an informed decision...du

The lakes I referenced are fertile - they're all fertilized, the 150-acre one by TWRA and the 56-acre one by moi (previously by a man who works for the owner). Added fertility is just more plankton for the GSH and shad to hog from the bluegill.

Here's what I think: bluegill may get pretty good-sized in extremely optimal, unusual circumstances such as the phosphate pits in FL that Eric mentions, but they'll never reach their maximum potential in BOW that have significant numbers (and the numbers will be significant if they're introduced) of either GSH, threadfin, or gizzard. I've wondered for a while now why the FL state record for bluegill (2lbs. 15 oz.) is smaller than the records of several states farther north with drastically shorter growing seasons; but if these other forage species are very common in FL, that could certainly explain it. Most state-record bluegill came from ponds, including the world record (Ketona Lake, AL, 1950, caught by T.S. Hudson on a topwater bass plug); ponds, until recently, usually didn't have GSH or shad. Just my opinion on the matter.

As to controlling gizzard shad, hybrids don't get large enough to eat an 18" gizzard shad - nothing short of a striper or a muskie or a flathead catfish is going to eat a really big gizzard. And even with one of those species it would have to be a really exceptional fish that doesn't come along every day.

On catfish, I agree with you 100% - if you plan on feeding bluegill, skip the CC unless you enjoy frustration and wasted money. In my observation they don't just outcompete the bluegill, the bigger CC will bully them away from the food so they get little to none. A ten-pound CC tail-slapping a 9" bluegill is akin to a normal-sized pondmeister such as myself trying to block Albert Haynesworth - ain't gonna be pretty.

Good questions, DU. There have been studies done on the negative impact of shad on bluegill growth. Here are two on the negative effects of gizzard shad, both in ponds and reservoirs; one study was in NE, the other in IL:

http://cat.inist.fr/?aModele=afficheN&cpsidt=14662602

http://afsjournals.org/doi/abs/10.1577/M04-008.1

Threadfin shad and GSH are not mentioned, of course, but they eat the same foods as gizzard shad; the key is the competition with bluegill for food sources. Every time I've ever fished a lake in which any of the three had been stocked, the average bluegill size was cut at least in half of what it had been.

Tilapia are perhaps a slightly better option, as far as the bluegill are concerned, but they love pellet food and will thus compete with the bluegill on that front.

It is very difficult to manage for both trophy bass and trophy bluegill. The two ways to go about it are 1) regimented harvest of both such that neither ever becomes overcrowded, a "balanced" pond such as most state game and fish agencies used to recommend, and 2) stocking of a predator above the bass, northern pike or tiger muskie being my preference, that will keep the bluegill and bass both thinned. With either method, you probably wouldn't get LMB as big on the top end as you would with a very forage-heavy approach, but you'll still get bass much bigger than if you let them overcrowd to make the bluegill bigger, and you'll get huge bluegill if you feed and fertilize.

I would say, if trophy LMB are your primary goal, go ahead and stock tilapia, and probably also GSH; with regular feeding by automatic feeders, you can still get some big bluegill, they just won't be two-pounders. If you want two-pound bluegill, though, don't stock anything that's going to compete with them for food.

I re-read your post, DU. You're in TX, right? If so, it's a very reasonable goal to produce both 8-10 pound bass and 8-10" bluegill in the same pond. If you were talking the extreme top end of both species, i.e. 14-plus-pound LMB and 2-pound bluegill, that would be very difficult. But for your region, those are quite doable goals. I fished a pond a couple months ago in MS from which I caught several bluegill well over 10", and that same pond has produced multiple LMB over ten pounds in the past year. And that pond isn't fed.

You just have to keep the pond well in balance, well below its total maximum carrying capacity. You can do that either through harvest of both species, or an additional predator, which is my preference because it's more constant and sustaining as long as you keep the predators stocked (pike/muskie won't spawn in TX, especially if you go with tiger muskie which are sterile). If I were in TX I could get your pond to having 8-lb. LMB and 10" bluegill in four years, possibly sooner. You should fertilize once a month from March through October, install at least two and preferably four or five automatic feeders, and keep the populations of both species balanced. If you've got an ample budget for the pond, you could have as many as two feeders per acre, which would turbo-charge the growth of the bluegill and bass both, the bluegill directly and the bass through the bluegill, by way of more good-sized meals for the bass in the form of more 5-8" bluegill and more reproduction of the bluegill.

My goal would be to produce a balance between the bass and bream. I am not trying to break any records. I just want to introduce another forage species to take the strain off of the bream.

I have heard tilapia mentioned as an alternative. But there are problems with them. It is illegal to posses them alive in florida. It doesnt get cold enough here in the winter, so they live and keep reproducing. But I have fished many lakes/ponds/rivers in the area that also have tilapia in them. The bass and bluegill seemed better than average.

Not that I would break the law but, I could easily get my hands on some tilapia and breed them outdoors until I have enough to stock..What do you guys think?

GSH and threadfin would work just as well as tilapia for providing extra forage, probably better since they don't grow large enough to be too big for the bass to eat. Threadfin don't eat pellet food, to my knowledge; I've heard of GSH doing so but haven't seen it personally; but tilapia definitely do, so that's another strike against them if you're feeding.

Another part of the answer to your question, DU, is that the stocking of threadfin or gizzard shad or GSH, any one of the three, in addition to introducing competition for the bluegill's food, takes a significant amount of the bass's prey focus off of the bluegill, thereby causing the bluegill to overpopulate. I had suspected this just from the number of bluegill in the 56-acre lake I'm working with, and the studies I linked to above specifically note this factor.

Walt do you have those studies ? I have seen shad added to many lakes/ponds with all different outcomes. I have read many studies on the subject both as to GShad and Tshad. Generalizations are suspect. I have added below some text which should show the uncertainty and differences. From these I gather that GShad are a problem unless you want and have big LMB as noted above. TShad are not the same as they often don't compete significantly with BG and don't suppress the recruitment of LMB and BG like GShad. Even in the GShad studies it is not so much the competition for food as it is reduced predation on BG and other factors. The last study below is an examination of some 60 prior studies on GShad and TShad as forage .

The only 2 methods I know of for trophy BG ponds are LMB crowded ponds or all male BG ponds. Trophy HBG ponds are a combo of those 2.


Direct and indirect effects of gizzard shad on bluegill growth and population size structure
"These results demonstrate that the presence of gizzard shad is associated with reduced bluegill growth rates and adult size structure and that mechanisms other than direct competition for food resources may be responsible"


Effects of Waterbody Type and Management Actions on Bluegill Growth Rates
"Managers should recognize basic differences in growth patterns between water body types when determining which management actions should be implemented or when evaluating their success."

The Influence of Gizzard Shad (Dorosoma clpedianum) on Plankton Community Dynamics in Earthen Ponds


Date: 1995
Abstract: The impacts of gizzard shad on plankton community interrelationships were evaluated in six, 2 to 5 ha ponds over a 3-year period. All ponds were stocked with largemouth bass (Micropterus salmoides) and sunfish (Lepomis spp.). Three of the six ponds were stocked with gizzard shad at random while the other three served as controls. The zooplankton and phytoplankton were sampled and analyzed three times during 1992 (before shad introduction) and twice a month during the growing seasons of 1993 and 1994. Water quality variables were measured once in 1992 and every other month during the growing seasons of 1993 and 1994. Phytoplankton primary productivity was measured three times in 1992 before the introduction of shad and once a month during the growing seasons of 1993 and 1994. Zooplankton density, biomass and size were affected by gizzard shad during summer, 1993 and spring and fall of 1994. Statistical differences between treatments occurred in spring, 1994 (p<0.13) with higher density, higher biomass, and smaller organisms in the shad treatment. Phytoplankton density, diversity and primary productivity were all higher in the shad treatments (p<0.13) during fall, 1994. Shad influenced the plankton community in a web-like fashion directly impacting zooplankton and phytoplankton simultaneously and indirectly affecting phytoplankton by altering the zooplankton. Shad shifted phytoplankton size structure by first reducing large phytoplankton (>70 mm) in the shad treatment immediately after shad introduction in 1993 and enhancing small phytoplankton (C28 mm) a year after shad introduction (1994). Through this size structuring, shad increased the photosynthetic efficiency of the phytoplankton community to twice that of ponds without shad by summer, 1994 (p =0.067) and increased primary productivity to 1.5 times that of ponds without shad by fall, 1994 (p =0.098).



Relationships between trophic state and gizzard shad, bluegill sunfish, and largemouth bass populations in three Alabama impoundments


Date: 1989
Abstract: Three Alabama impoundments were studied to analyze the relationship between fertility levels and the population and community structures of several species of fish. Chlorophyll a concentrations were used to classify lake trophic status. Fish communities and populations were similar in structure between the two eutrophic systems and differed from the oligotrophic system. Eutrophic systems were shown to have a higher relative abundance of prey species, in particular gizzard shad. Overall production was lower in the oligotrophic systems. Community structure in the eutrophic systems reflected a greater influence of gizzard shad. Bluegill abundance doubled while gizzard shad numbers increased twentyfive-fold. Largemouth bass increased eight times in number. Prey populations were overcrowded, characterized by slow growth, poor condition, and reduced spawning, due to the high relative abundance of gizzard shad. Predator populations showed low recruitment and poor condition in smaller fish due to lack of suitable size prey.The relative abundance of predator species increased in the oligotrophic system. Bluegill were in better condition and had better distribution across size classes. Young of year and age one gizzard shad were absent from sampling throughout the year.



Title: The effects of threadfin shad as a forage species for largemouth bass in combination with bluegill, redear, and other forage species


Date: 1976
Abstract: Threadfin shad, Dorosoma petenense (Gunther), were stocked in ponds with an established population of bass, bluegill, and redear and in three ponds containing bass, golden shiners, and fathead minnows. Comparisons of fish populations were made before and after the first successful spawn of shad. The production of bass with bluegill and redear plus shad was essentially the same as with golden shiners and fathead minnows--59.2 pounds per acre and 58.7 pounds per acre, respectively. A significant increase in the growth and condition of bass was seen in the pond stocked with bluegill and redear after the first shad spawn while no change was seen in bass survival.Bluegill and redear recruitment increased significantly after the shad population became established. This apparently was caused by a decreased rate of predation by bass. As a result, the catch per unit of effort of bluegill and redear decreased significantly after the introduction of shad. Bass were in better condition after shad stocking while no change in the condition of bluegill and redear could be detected. In ponds stocked with forage minnows, fathead minnows disappeared the second summer after stocking. An F/C ratio (Forage/Carnivorous) of 2.7 and an A value for bass (percentage of bass over 10 inches in length) of 93.4 was computed for the pond, indicating a bass-crowded condition due to heavy predation on the forage species.From these data, the stocking of shad as additional forage in bass-bluegill-redear ponds cannot be recommended. The stocking of shad with bass and other forage species appears to offer some advantages to bass fishermen if the production of forage species can be increased.


Stocking Threadfin Shad: Consequences for Young-of-Year Fishes

DENNIS R. DEVRIES, ROY A. STEIN, and JEFFREY G. MINER
Ohio Cooperative Fish and Wildlife Research Unit,3 and Department of Zoology The Ohio State University, Columbus, Ohio 43210, USA

GARY G. MITTELBACH
Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan 49060, USA

Abstract

Threadfin shad Dorosoma petenense are commonly introduced into reservoirs to supplement prey available to piscivorous fishes. To determine how early life stages of threadfin shad and their potential competitors and predators interact, we introduced this species into two Ohio lakes—Clark and Stonelick—and evaluated how its young of year influenced young-of-year bluegills Lepomis macrochirus and largemouth bass Micropterus salmoides. After adults were stocked in April, peak abundance of young-of-year threadfin shad occurred in August in both lakes. Bluegills generally spawned earlier than threadfin shad, which apparently reduced competition between young of these species. In Clark Lake, young-of-year threadfin shad did not reduce zooplankton populations, but in Stonelick Lake, peak abundance of young-of-year threadfin shad was followed by a precipitous decline in zooplankton. Data on cladoceran birth rates indicated this decline was due to increased predation by threadfin shad. Survival of bluegills to a size at which they move into the littoral zone also declined in Stonelick Lake, perhaps because of the virtual elimination of zooplankton. Limited survival of bluegills in turn contributed to reduced growth of young-of-year largemouth bass dependent on them as prey. Given that zooplankton declined in one but not the other lake, interactions among young-of-year fishes due to annually introduced threadfin shad will likely vary among systems and years. Nonetheless, introduced threadfin shad could, in some systems in some years, negatively affect growth and recruitment of the very species they were meant to enhance.



Young-of-year threadfin shad, though their

abundance peaked in late summer, co-occurred at

low densities with limnetic young-of-year bluegills

during May through September in Clark Lake.

When both species co-occurred in the limnetic

zone, they ate only limnetic zooplankton; however,

diet overlap values were typically <0.50.

Once blue gills moved inshore, the potential for

competition with threadfin shad declined greatly.Diets of bluegills collected from the littoral zone

did not change between 1987 and 1988 in Clark

Lake; all prey types (littoral, limnetic, and cyclopoid

copepods) were eaten. Though collected inshore,

bluegills apparently moved far enough offshore

to consume some limnetic prey, but they ate

enough littoral prey to reduce overlap with threadfin

shad, which continued to feed entirely on limnetic

prey.

Consequently,

although competition between young-of-year

bluegills and young-of-year threadfin shad may

occur (particularly during August in Stonelick

Lake), the outcome of such interactions in a lake

ultimately depends on abundance and species

composition of the zooplankton community and

on the relative spawning times of the predator

fishes. As demonstrated by our results, these factors

vary among lakes and years, making generalization

difficult.Thus, interactions between limnetic young-ofyear

threadfin shad and bluegills may have a pronounced

negative effect on young-of-year largemouth

bass growth if they lead to reduced survival

of young-of-year bluegills in the limnetic zone and

then to reduced recruitment of bluegills to the littoral

zone. Additionally, slower growth may reduce

overwinter survival of young-of-year largemouth

bass if overwinter survival depends on body

size and fat reserves (Adams et al. 1982a, 1982b;

reviewed in Adams and DeAngelis 1987). As a

consequence, the very management practice intended

to enhance the fishery for adult piscivores

may reduce survival of the target species. Although

these negative effects are not direct (unlike

the positive effects of increased prey availability),

they could have substantial consequences over

several years of such management manipulation





Manipulating Shad to Enhance Sport Fisheries

in North America: An Assessment

DENNIS R. DEVRIES' AND ROY A. STEIN



Manipulating forage fish populations to enhance sport fisheries is a common management

practice. Here we review the literature dealing with manipulations of gizzard shad Dorosoma

cepedianum and threadfin shad D. petenense to assess whether or not this practice has been

successful. Shad introduction has tended to enhance predators, such as white crappie Pomoxis

annularis, black crappie P. nigromaculatus, and largemouth bass Micropterus salmoides, and negatively

affect presumed competitors, such as bluegill Lepomis macrochirus. However, responses

have not been consistent within a species: some studies document negative responses of predators

or positive responses of competitors to shad introduction. Depending on the study, target species

have experienced negative, neutral, and positive effects due to shad removal, making generalizations

impossible.

We were not able to generalize about how shad

influence sport fishes. Although bluegill appeared

to be more negatively affected by shad than crappies,

the response of largemouth bass being intermediate

between the two, we cannot draw definite

conclusions because the entire range of results occurred

for each target species.







The results presented here indicate that several

aspects of whole systems must be quantified if we

are to assess how forage-fish manipulations affect

a fish community. Based on our review of manipulations

involving gizzard and threadfin shad, potential

competition and predation, spatial refuges,

indirect effects through common predators and

prey, and the influence of ontogenetic shifts in

habitat and diet of the target and introduced species

are all critical to being able to predict the influence

of a forage-fish manipulation on a target species.

In Clark Lake, young-of-year threadfin shad did not reduce zooplankton populations, but in Stonelick Lake, peak abundance of young-of-year threadfin shad was followed by a precipitous decline in zooplankton. Data on cladoceran birth rates indicated this decline was due to increased predation by threadfin shad. Survival of bluegills to a size at which they move into the littoral zone also declined in Stonelick Lake, perhaps because of the virtual elimination of zooplankton. Limited survival of bluegills in turn contributed to reduced growth of young-of-year largemouth bass dependent on them as prey. Given that zooplankton declined in one but not the other lake, interactions among young-of-year fishes due to annually introduced threadfin shad will likely vary among systems and years. Nonetheless, introduced threadfin shad could, in some systems in some years, negatively affect growth and recruitment of the very species they were meant to enhance.

This very clearly states that in one of the two lakes studied, threadfin had an even more negative impact on the bluegills' food source than gizzard shad. And, as I added in my last post, competition for food is not the sole reason shad of either variety, in addition to GSH, will invariably cause a decline in the average size of a bluegill population; the more fusiform prey cause the bass to prey less on bluegill, allowing them to overpopulate their food source. But beyond that, I base my conclusion first and foremost not on the studies, which I referenced just for substantiation, but rather personal observation of fishing many lakes and ponds that had once had large bluegill but since the addition of a fusiform prey no longer do.

I pasted links to the studies I was referring to in the same post I initially mentioned them in. I think it's on page 1.

Can any of you speak to the affect of tilapia on populations of bluegill? It is illegal to posses tilapia alive here but if one of the smaller species were to find its way into my lake in large enough numbers to become established, what would the affects be?

From what I understand, if tilapia overwinter as they do in much of Florida and their numbers boom, they can out compete native fish to include bass for spawning locations. Typically as tilapia biomass increases, native fish biomass decreases...

A simple breakdown: http://home.earthlink.net/~wweinkle/TILAPIA.HTM

Straight from Pond Boss Magazine on the subject of gizzard shad.

http://www.bassresource.com/fish_biology/gizzard_shad.html

So tilapia will have to be controlled if they are introduced? They are easily harvested with castnets right?

I was just considering them because they occupy a seperate niche.

This kind of information, even when it is contradictory, is the reason I really like this web-site. You know, I don't have a clue about all the interactions between forage/predator/environment..., but I am learning. Citing refereed scientific articles and relating personal antedodal evidence are both important to me in deciding how to proceed with stocking. How we are going to manage our ponds will have more to do with the outcome than anything else, so it makes it really hard for you experts to give us advise in absolute terms. But, I now know that TFS and GSH MAY affect the size of BG due to overpopulation. That potential overpopulation of BG can lead to stunting from a lack of food source( that supplemental feeding MAY improve). The LMB would rather eat "non-spiny" fish, like TFS & GSH{this makes sense because LMB eat all the FHM first} and so the BG overpopulate, hence stunting. This information gives me pause as to how to proceed. So, even if it's confussing, I'd rather know now ALL the possible ramifications than 3 years from now say "I wished I'd known".,..du

Yes, tilapia will have to be controlled if they are introduced into a central/south Florida pond. Personally, I would skip the tilapia in that situation. Up north where they die off each year. It think they have more pluses than minuses. Where they overwinter, that isn't the case... The FWC has struggled for years to control tilapia and other non native cichlids. Peacock bass have helped, but tilapia are hard to control.

That is the biggest thing with fisheries management... There is no absolutes! One study doesn't prove anything. 10 studies MIGHT prove something.

You are right about there not being any absolutes. All I want to do is add another forage species, but it isnt that simple. I still have no idea what I will stock. I just don't want the bluegill and redear in my lake to be overcome. I have seen ponds where bass survive off their own spawn. I want to avoid that.

I think in Florida golden shiners are a good choice. A much better choice than tilapia. You may also want to consider lake chubsuckers. Do a search on here, we have talked about them much recently... Todd Overton just started selling them this year. They are rather common in most lakes in Florida and IMO are a top notch bass food... You may be able to collect some from the wild in FL as well.

A Florida Lake Chubsucker

CJ

Here is the original discussion thread on the K Nutt article in PB.

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=11350&fpart=1

Here is a later discussion.

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=159008&fpart=1


Walt you made my point. It depends on the pond. The chart tells the story - in half of the 12 studies addressing the effect on BG by shad 6 were positive to neutral and 6 were negative to neutral. But more important are the statements that blanket generalizations were not possible.

The study with LMB , BG and TShad in ponds stated " Bass were in better condition after shad stocking while no change in the condition of bluegill and redear could be detected. I can only find the links to the 2 Abstracts but I have those studies elsewhere.

Yes zooplankton #s were reduced in Stonelick lake but look at the authors conclusions about that :

"Consequently,

although competition between young-of-year

bluegills and young-of-year threadfin shad may

occur (particularly during August in Stonelick

Lake), the outcome of such interactions in a lake

ultimately depends on abundance and species

composition of the zooplankton community and

on the relative spawning times of the predator

fishes. As demonstrated by our results, these factors

vary among lakes and years, making generalization

difficult."

I think the odds of TFS introduction being highly detrimental to sunfish populations increases as pond size decreases.

The general recommendation is not to stock TShad in ponds less than 3 acres. The pond needs to have a pelagic niche with plankton. The concept is BG eat in the littoral zone (one niche ) while the TShad feed in the pelagic zone (second niche) so less chance of competition for food.

I know they use Golden Shiners (adults) for bait when targeting LMB in Fl. I have first hand experience of them eating 1/4" pellets. If I lived in Fl. and wanted to add a food source for my LMB, I'd put in either Threadfin or Golden Shiners. Going by ewest's recommendations, if the pond was <3 ac, then it would be GSH.

I'm trying to remain calm as I respond to the posting of a link to this particular article, which is probably the most scientifically careless and irresponsible, not to mention inaccurate, single article published in the history of pond management. I read that article a while back on another website; I comforted myself with the thought that perhaps it hadn't been widely read. That article is one big collection of falsehoods, false conclusions, and sloppy, inexhaustive, poorly founded research trotted out as conclusive science. A study done on a lake that already had gizzard shad, which were then reduced and then brought back to prominence? How in the world does that make more sense than to take a lake that has no gizzard and add them, which would give a much clearer picture of their effect on fish populations? If the bluegill were already overpopulated thanks to insufficient pressure on them by the bass, temporarily lessening the shad would do absolutely nothing to remedy the overpopulated bluegill, therefore not affecting their size - stupid. Or what about using total poundage of a species in a lake as a measuring stick of the health of the population, not even bothering to state the average size of the individual members of the species? And how in the world did the author determine that, contrary to the findings of every biologist who has ever studied bluegill previously, bluegill don't eat plankton? Did he cut open their stomachs and when he didn't find any microscopic plankton conclude that they hadn't eaten any? Perhaps he tagged the benthic invertebrates and then found them in the bluegill's stomachs? Or maybe he counted the plankton and recounted them a month later and saw no change? I'd really love to hear how he scientifically proved bluegill don't eat plankton. There's no mention whatsoever of his study methods, which doesn't exactly go a long way to inspire confidence in his conclusions.

The total poundage nonsense: a lake with an overpopulated bluegill population is always, always going to have more total pounds of bluegill per acre - they're just going to average about one-sixth as much in weight. I've fished not one or two but several lakes that had had large bluegill at one point, then subsequently had either threadfin or gizzard shad (or GSH) stocked and subsequently saw a dramatic drop, as in more than 50%, in the average size of the bluegill. It didn't happen twenty or forty or sixty percent of the time, it happened 100% of the time. This article is careless and irresponsible.

I believe 100% that gizzard shad can help a pond owner who cares about nothing but trophy bass, grow larger bass than he could without the gizzard, and for that reason, I think they have a place in pond management. But this article tries to say there are no negative effects in any way, and that's just not true, and the shoddy attempts he makes to substantiate his argument are really an insult to anyone who's ever fished a lake that had once been a bluegill honeyhole and has now been ruined by shad. For that matter, it's an insult to anyone who puts faith in the scientific method and the notion that someone who conducts a study does so objectively and rationally, rather than with an agenda and no concern for accuracy, reliability, etc.

Yeah we use golden shiners for bait all the time. If the shiners will take pelleted food then I guess they are most likely my best bet. I have never heard of chubsuckers. I will try and research them.

Okay, so I just read the two links Eric posted before I posted my rant about the Kendric Nutt article, and was comforted to see that Bill Cody had already done a good job of putting the article in context and qualifying a lot of Nutt's conclusions. But that article is really, really bad science. It would be one thing if he had written an article stating, "If you only care about huge bass, you need gizzard shad."

I agree that GSH would be a better option than tilapia in FL. And big bass love them.

Walt this year I had a record spawn of shad and I think most of the schools that I could get close enough in the boat to see were threadfin. Most of the fish in the schools are very small in size. My question is why don't the bluegill benefit from feeding on these very small fish? Many of the schools look like they have fish in them that are less than an inch long and I often catch bluegill on shiners that are two inches long. I could understand it if the schools only stayed out in the middle of the pond but often the schools stay right along the bank. In fact I watched a bass hit a school that was near the shore and land on the bank and then flop back into the water.

Bluegill will prey on them, to be sure. The problem is that the threadfin take pressure from the bass off the bluegill to the extent that the bluegill overpopulate, and when that happens their growth is severely curtailed. If the bluegill don't overpopulate, there's still the issue that all of those small threadfin are directly competing with the bluegill for food i.e. plankton.

But that's just my experience. Eric has fished lakes in FL with threadfin that also had large CNBG, so perhaps TSH are a different animal there than they are in TN. Florida LMB are not northern LMB, and that may have a lot to do with the equation.

Some lakes with high populations of GSH do grow rather large sunfish. A prime example of this would be Deep Creek Lake in Maryland. The lake is full of GSH from fry to 10" pike candy. Yet, the lake produces hundreds of citation BG and PS every year including the state record BG at 3 lbs, 7 oz. The old 3 lb record was also caught out of Deep Creek Lake. I've personally caught over 2 dozen BG over a pound out of the lake.

There aren't any shad in the lake and I hope it stays that way. Another lake near my house is shad free is consistantly produces quality BG while many of the other similar lakes around it contain shad and have poor sunfish populations as far as quality sizes go.

Once again, "It all depends". I'm just never sure on what the parameters are and whether they were all considered.

We once briefly touched on determination of forage load as relating to the predator/prey relationship. However, if we acknowledge that, at some point, virtually everything is a prey to something else, we find a slippery slope. I doubt that any predator does a taste test on anything else. I believe that it depends more on availability, accessability and ease of capture. If the caloric intake exceeds the energy expended, any predator will predate on anything else, whether it is on land or water.

So, we always have to go back to the Economists favorite term of ceterus parebus meaning all other things considered equal. No matter how badly you want to, you cannot draw absolute conclusions by studying a limited population. That's why we have to have control groups and test groups to do analysis and sampling. And that is only after formally defining the parameters of any analysis or test. Only by considering and studying populations over wide ranges can any credible conclusions be drawn.

Thank you Guv. As usual you hit the nail on the head !

Walt you are not the first reader to draw that conclusion about the Nutt article. He is talking about only a Trophy Bass lake. That is not the impression many readers come away with however.

In fairness K. Nutt is an outstanding fisheries scientist and pond mgt is his business. He has seen and worked on 10 times as many ponds as all of the posters on this thread combined. I believe the purpose of the article was to remind us that GShad are a tool and as Walt said " I believe 100% that gizzard shad can help a pond owner who cares about nothing but trophy bass, grow larger bass than he could without the gizzard, and for that reason, I think they have a place in pond management." I would add with the right use of the tool (GShad) at the right time. I think K. Nutt's info on the SEP website in the second link above (bottom of pg 1 of link) clears that up.

Interesting about Deep Creek Lake, CJ. I wonder if the pike offset the GSH by keeping the bluegill thinned to the point they grow well. I've seen the picture several times of that monstrous state record bluegill that came out of there...I read somewhere it was caught off a dock by a kid fishing with a bobber.

Maybe I'm just naive, but it seems to me that a scientific study utilizing small ponds(1-3 acres) could be done to determine the effects of different forages on each other. There seems to be no arguement that TFS, GShad, & GSH usually have a positive effect on LMB growth, so the question here is how much if any negative effects do they have on BG. Can't this be determined over a say, 3 year period by stocking BG and LMB in one pond, BG, GSH, LMB in another, BG, TFS and LMB in another, BG, GShad, and LMB in another. The ponds would treated all the same, ie:no feeding, no fertilizing, just mimic what happens in nature. It looks like to me from reading these posts that this question hasn't been answered, but there are lots of different opinions..du

david u studies on different forage species and combos (not exactly as you stated but close) were done by Swingle from 1930s to 50s http://www.sdafs.org/fmsafs/hoe/swingle.html. The ones the rest of us posted about are building on those older studies. The last one I posted is a survey of 60 such studies.

The difficult part is ponds and the food web are so dynamic that the results vary a lot from year to year and pond to pond. The results in the test ponds could be very different from one attempt to the next. Ponds a few hundred yards apart can react differently not to mention hundreds of miles apart. The food web is a very complex subject . For sure it is not just a simple food chain pyramid as shown most places.

I am now in my fifth year of pond management and starting to finally understand the term "It all depends" and the most famous "what are your goals". My original goal was to have trophy "everything" but now I am starting to realize how much adding one forage to increase bass size decreases bluegill size. How having catfish especially, too many, which is what most of us who have catfish have. Can detrimentally affect almost everything. Introducing anything new changes everthing. Is it good or bad It all depends on your goals and you may not even know for years.

Deep Creek Lake is pretty cool. I am not sure why the sunfish get so big, it is deep and cold at a high elevation. Ice fishing is big there for both BG and YP. It has a two story fishery with rainbow and brown trout. Definitely in the top 10 favorite places to fish. It's just a bit long of a drive from my house to get their regularly with too many other good places closer.