Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Trying to control excess GSF

Hello everyone from Central Illinois! I am a village trustee in Central Illinois and among my responsibilites is the local pond. Our pond is 3 acres and was dredged out 20 years ago to 14 feet. Since it was not really done properly (no silt trap) it has since filled in to a max depth of 7 feet.

Now on to my situation. This last summer I noticed that we have alot of 1 to 3 inch HBG in our pond. We had a fishing derby last fall and I bet the kids caught two thousand literally! The pond is stock with decent sizes 2-6 pound catfish. Last fall the state put in 100 5-8 in LMB which obviously was not taking care of it. Three weeks ago I added in 300 LMB in the 5-8 inch category and 400 cc in the 8-10 inch range. I am hoping that these fish can help to get things back in control somewhat. In two years I am planning to have the pond dredged properly with a silt trap before the inlet. Sorry to be long winded with this but I wanted to give you a background. Will this new addition of fish help in getting things back in the right direction? Thanks in advance.

welcome to PB IL....get used to the acronyms

how do you know they are HBG?

are you sure the pond infill is silt and not muck accumulation? if muck, aeration might fix problem, if silt, then digging out is appropriate.

i'll let others here address your fish stocking questions..(i'd have probably dug first and started over.....but that's me).

Can you post a picture of one of the HBG? If you PM me I will post it for you. It seems somewhat unusual to have an overpopulation of HBG. Are you certain they're not green sunfish? Not doubting your ID skills but we need to make certain we're talking about the same thing.

Bruce

Thanks for your reply. I am sure that they are HBG because that is what was put in there four years ago...at least that is what they ordered four years ago. I am not sure if it is silt or muck, I am also looking to add an aerator and a fountain this spring. If it is muck, would this be partially reversable as far as the depth? I was told that this strain was only supposed to have a 15% reproduction rate. The fish supplier is through the county and they have been doing it for sometime. I guess that they could have slipped up though. I feel as if I was handed a mess with this pond. It is really cold tonight 17 degrees. It is supposed to warm up possibly next weekend 8 days away. If it does I will go down and try to catch one of the little snots and take a photo.

Oh yea also the the HBG if that is for sure what they are...are partially stunted. Some of them have larger eyes than what they should have for their bodies. I wanted to throw some Red ears in but was afraid that they would be eaten right away. I guess I will be able to start clean in a couple years but for now I want a decent fishing pond for the kids of the community! Once last note, about two months ago I caught about a 1.5 lb bass that had a full belly so I know that the few bass that were in there were eating some of the HBG.

It is normal for young 1-3 in. BG and HBG to have large eyes and to be a lot of them present. This is a 60 day old BG. Body condition is a better indicator on small BG of stunting.

I thing you have already taken the steps to control the situation. 400 bass and 400 CC in 3 acres should knock back a buncha small fish. Then, you gotta figure on LMB reproduction to increase the predator load. In about 2 years, or about the time you dredge, you may be looking for some forage to add or having a lot more fishing derbies.

I question whether your over supply is really all HBG offspring. They should be green sunfish and they usually only spawn annually. That type of over supply sounds like garden variety bluegills that someone may have added.

It very well could be true that someone added the BG. Being a community pond it is very hard to control what people may throw in at any given time. I caught a bullhead this summer and promptly removed him. I fish the area often and it was the first one that I have caught. The fish that were just added have been pellet fed. Unfortunately it is too cold for me to continue feeding. There is not alot of cover in the pond right now so the BG will have to swim from the shallows as the freeze takes place. I am sure as the go deeper they will be eaten.

Howdy IL,

Sounds like a manageable situation wrt the fish, with good advice already given. Please post pics of the sunfish, if possible, especially if there turn out to be different looking kinds present. What you know was stocked and what you were told were stocked may easily not be the only fish present. Helpful fishermen, local kids with aquarium releases, and alien fish abductors making return trips to Earth may have added something else. And we love to (try and) identify fish from pictures!

As to the Sediment buldup, perhaps the silt vs. muck (inorganic vs. organic) makeup can be estimated from the pond surroundings. Are there a large number of trees which drop leaves into it? Any highly prone-to-erosion areas in the watershed (plowed fields, construction sites)?

Would someone who knows more than me about northern ponds address the potential problems with high fish bio-mass in shallow ponds when it ices up and a large part of the pond is frozen to the bottom. Is this a winter fish kill in the making?

Longhorn -- the LMB stocking was a good plan. You've got to give the bass a few years to reach maturity, spawn, and start controlling the sunfish in a 3-acre pond. If you have the resources, or could talk the state into it, I would go with one more LMB stocking. I would try for 40/acre (120 total) of 8-12 inch LMB.

Ewest -- let's ask Longhorn the history of the pond. If the sunfish and bass have been in there for 4 years, then the winterkill risk must be somewhat low at his location? Anyone reading this from central Illinois? I assume that ice cover must not be too thick or last too long? Obviously, 7 feet of silt in what was a 14 foot deep pond is a problem situation.

No winter kills in at least the last 9 years. Really there are not alot of trees around and it does receive runoff from plowed fields. The sides are wrapped with rocks to reduce erosion. I will post some pics of the pond as well. Thus my thinking. The 7 foot finding was last fall I have now found out. We had a major drought last year, so I plan on taking a boat out this spring to get a more accurate number. Depending on the weather tomorrow, I may try to get down and catch some of the fish in question to snap some pics. The catfish have done very well in this pond for many years.

Firstly - I question the efficiency and percision of a dredging to 14 ft that occurred 20 yrs ago esp if it was done when the pond had water in it. Did Longhorn or anyone else measure the pond depths to produce a contour map after the dredging operation? 7 ft of accumulation is a whole lot of muck in 20 yrs (84in/20yr=4.2in per yr) but it is possible if lots of leaves and vegetation growth are deposited each year. Longhorn what is the typical annual weed-algae-tree leaf problem that gets deposited into the pond each year?

Secondly - Since it is a public pond there is undoubtedly a lot of greedy and unwise fish removal by anglers. Don't count on stocked fish to stay in the pond very long. Our local sportsmen club constantly has the pond raped by anglers-members. If this were not true a few bass 50-80 would be able to control the actual recruitment of Hy BG. Thus I as others highly suspect contamination from other more proflic sunfishes. I IL can keep the LMB in the pond long enough they should be able to get the small sunfish under control. IL - remember that a bass eats a sunfish about 1/3 the length of the bass. So if majority of your sufish problem is 4"-5" long then the size of bass you are stocking are too small to quickly reduce the overpopulation of "your" sunfish. Will the small bass stay in the pond long enough to grow to 13"-14" long?

Old catfish in a heavily fished pond can get conditioned to avoid most average anglers. Thus the larger ones may help in controlling small fish.

Thirdly - I agree with Dr Dave about the winter ice cover problem. Ice-snow cover in central IL should not be a big concern compared to the BOD (biological oxygen demand) problem.

Good point from Bill! I made an assumption, which is always foolish. I assumed that the expensive, advanced sizes of stocked LMB would be protected by a length limit. Longhorn -- do you have such a regulation? If not, I would recommend at least a 15 inch minimum length limit, and why not catch and release, at least for now? Also, there has to be some expectation of enforcement for a regulation to be successful. Will the local conservation officer/game warden be willing to help enforce the regulation?

I plan on ordering some signs prohibiting anything under 15 inches except for blugill to be taken from the pond. As far as the game warden I will see what I can do, however with the state cutting more and more off the budget it will be hard. The pond was dug out properly the last time. I know the guy who did it and he has dug many ponds in the area. He actually suggested to the village board many years ago to put in a silt trap and they would not. The pond was drained during the dead of winter when it was dug out. I am not sure if our police force could do anything with this as well. They help me with the fishing derby every year. Most of the sunfish are in the 1" to 3" range. How big can a regular sunfish get?

somebody's gonna have fun with this question.

IL, i know of green sunfish (GSF) ranging from 9 to 12 inches and well over 1lb, although GSF in yer area is likely not a popular choice. i'll concede the podium for others to report on maximum sizes for BG and RES.

It is pretty easy to get BG in the 6" to 8" range, and RES an inch or so bigger than that. I have even managed it myself. BG/RES in the 10" range takes a little more work, but I believe most PMs who want this as a goal can attain it. Maximum size for both species is around 12"-14"

BTW D.I.E.D.'s GSF are IMHO extraordinary and would have strained his creditability if not for the excellent photographic proof. As it is, we are in awe.

I plan on starting to feed them this spring which will hopefully allow the ones to large to eat to get some size. I also hope that it slows their eating a little so the fish are not all taken out before they can get some real size. While I do not think the pond gets fished real heavy, I do not know what goes on during the day while I am at work. There used to be alot of trees around the pond. Over the last six or seven years they have been replaced by smaller ones. Some of the fill in could be a result of leaves and debri. I have been addicted to fishing all of my life. I truly believe that I am having more fun trying to get this pond in shape than I ever have fishing. Is this common?

Around here's it's really common.

Here is a pic of what now I believe to be a standard BG?

IMG] http://i138.photobucket.com/albums/q274/IllinoisLonghorn/IM000539.jpg[/IMG]

Try the pic of the pond again.

That fish is a purebred green sunfish.

Beautiful pond.

Thanks Bruce, we as a village have worked hard over the last few years to make the pond appealing to the eye. I do feel however that we need to add some kind of plants to help create a natural habitat, and help with water clarity. Just imagine an aerator and lighted fountain in the middle! The fish measured at 3.5 inches. I went down today and caught 11 catfish ranging from 18" to 10 3/4. I logged all the info and will continue to log as I have time to fish it. I am hopeful that by adding some water structures (trees and branches) and feeding that I will get some size to the fish.

One last pic of the pond.