Pond Boss Forums INTRO Questions & Observations Where are my bluegills?

My pond is approx 5 years old. As the pond was filling I put in Largemouth bass, perch, trout,
bluegills, and flathead minnows. Everything did
extremely well except for the minnows. I feed pellets all year long except for the winter months. Every year the ice fishing for the bluegills has been extremely good. Last fall we
caught some really giant bluegills. Now I can't seem to find these fish. All of the bluegills in
the pond were all the same size. What is the life span of a bluegill? Could they have all died from old age? They were all hybrids, and I
have caught a few bluegills this winter that were half the size of the big ones that we had caught this last fall. All of the other fish are doing just fine. Where did the large bluegills go? I have used underwater cameras to look for them through the ice w/o any luck.

I have seen literature that shows only a 4 year average life span for bluegills. If you do not have recruitment of several ages classes (which you won't for hybrids) it's no suprise you would have a sudden lack of large bluegills if they were dying out.

Even with bluegills that are not hybrids I have seen fisheries survery reports predicting a decline in bluegills in future years when there is a abundance of larger bluegills but not much recruitment.

Thank you for your reply. My largemouth bass are now 18 inches long. Because of this I'll
have to plant the biggest bluegills that I can
find or they will be eaten by the bass. I guess
I should have been planting the bluegills every
year with the hopes of maintaining a viable gill population.

If you really care about your bass you should be planting regular bluegills. It's surprising your bass are doing well if they are. Hybrids are about 90 percent male and don't provide a lot offspring, therefore, are lacking in forage for your bass.

Pay attention Lance,
Cecil gives good advice!
He & others here will help you have the best pond you could have!

I definitely will pay attention. I can't believe
how many mistakes I made when initially stocking
the pond. At that time I wasn't aware of this site. Now I have 18 inch lmb, 12 inch perch, 16 inch rainbow trout and very few bluegills. I
am going to try to find someone that handles larger non hybrid bluegills and stock those. Somehow I think I need to increase dramatically the forage fish in my pond. Right now all I see
are 3 to 4 inch lmb. Thanks again for your help.
I just can't get enough of this great site.

Hello, I have a recommendation for continuous stocking of bluegill. I can catch my legal limit at any one of our 3 local lakes using the old cane pole and worms. I legally transport them to my pond. Lots of fun but perhaps a bit risky considering disease, but I figgure the birds are doing the same with the diseases. Anyway, consider catching some medium size natives for restocking your pond, year round, year after year. Take some kids fishing for a faster restock rate.

Cecil, Bill and others. The reason given for poor reproduction of hybrid bluegills is that they are 90-95% males and only 5-10% females. However, even with only 5-10% females, there should be more than enough females for adequate reproduction. There must be other factors involved. Any ideas?

We've had the same situation on our 2-acre pond. 7 years ago we stocked 300 LMB and 300 hybrids. 2 years later 300 small catfish and 500 fatheads. Last year we were still catching a few HUGE hybrids, but have seen no recruitment. All fatheads and catfish were consumed by the bass which completely dominate the pond.

I don't personally believe there are too many other factors. It's mostly a matter of the fewer offspring from the hybrids not being able to keep up with the predators. However, after reading up lately on fish gentics, the fact that the gene pool will be so small with fewer offspring, and is already limited in a small pond, lack of fecundity of the females in later generations due to inbreeding could be another result of using hybrids.

Hybrids IMHO have their place, but if you want a healthy fast growing bass population you need more reproduction then they provide by themselves. I think fish farmers pushing hybrids as the wonder fish for all ponds is disengenuous (sp?) and has probably accounted for more than a few ponds not living up to expectations. Think about it. If a pond owner has to purchase more fish every few years that is job security.

I'm really going out on a limb here....
IF I remember my biology, if you cross a Hybrid and Hybrid and get five offspring, you generally get 2 native BG, 2 Green Sunfish, and a Hybrid because of the genetic blender. Now if each seperate species has its own breeding zones, they are not likely to re-hybrid, plus the fact that most of them are male. So undesireable fish (green sunfish and hybrids)outnumber the native bluegill, outcompete them for food, and also compete for food with the bass. So if a hybrid coupling produces 10,000 young (I have no real idea, just ballparking) only 4,000 are native bluegill (what we really want) only 400 are going to be reproducing females. Looks like pretty stiff odds to me.

I really don't know if this is the way it is, I'm just bored at work and needed to write something!

If I remeber my genetics correctly...

When you cross two hybirds you get 50% hybrids (BG), 25% Bluegill (BB) and 25% Greens (GG). Remeber the "square"?
---B G
B BB BG
G BG GG

(in this example pure bluegill is BB and a hybrid is BG)

Unfortunatly fish are not 50% blue and 50% green
they are in reality bluegreen. When a fish lays an egg it has 1/2 of a genetic code. But it is not the same half that it got from one of its parents.
They (and us) recombine the chromosomes into new combinations of genes. So you will almost never (if ever)get a pure BG back from hybid parents. And I would think it is impossible after the first generation. If the F1 generation doesn't produce a pure bred bluegill then they never will.

Good thread, guys. Hybrid bluegill live four to six years, depending on location and individual fish. Hybrids are like a mule...with one catch. A few can reproduce. A mule can't. But, when you have top heavy predator pressure in a northern pond, expect the minimal hybrid sunfish which reproduce to provide a snack for hungry fish. Pure bluegill are the backbone of the food chain for largmouth bass, but in northern ponds, bluegill only spawn once, maybe twice yearly.
So, bluegill play a role more as a secondary game fish than a significant source of forage. But, since they spawn, a pond manager stands a better chance of establishing a population with these panfish. Go get adult bluegills.

Now I remember the square! Dang, its been way too long. Thanks for straightening me out!

Just read a paper about a small 5ha lake with yellow perch, walleye and bluegill.

Bluegill experienced 92% mortality their first year of life. and 91% mortality in thier second year of life. In years when no one fished the pond age 3 fish had 49% mortality and with fishing mortality was 79%.

So after just three years between 1.5-3 fish would survive out of 1000 age 0 BG. So what if you have 10% females instead of 50%? and the initial size class isn't 1000 but instead 200? When fish experience this kind of mortality you need alot of them to keep the population going.

Those numbers are deceiving. Reduce the walleye and perch population by half and don't be surprised to see exponential changes in statistics of bluegill. Plus, there's no account of perch or walleye reproduction. That has a direct impact of survival of small bluegill. Sounds like that paper is exclusive of ponds except that one. Funny, if the same study was done with the same pond again, I bet the numbers would be different. In other words, dynamics and other variables influence those results.

Studies on ponds and lakes can have great value in general, but researchers will tell you that ponds are open systems with a myriad number of variables. Mortality rates can be impacted by weather, angling pressure, predator/prey balance, availability of food items and water chemistry. It's a lot more accurate to use scientific sampling measures such as gill nets, trap nets, or electrofishing to see what HAS happened than it is to use a single study to guess what WILL happen.

Crossing two hybrids never yields a pure bred offspring in any percentage. The common term is F2 hybrid. Crossing two green sunfish/bluegill hybrids would result in an entire generation of F2 hybrids, none of which are either completely bluegill or green sunfish. Interestingly enough, a lot of the F2 may "look" like a green sunfish but they really aren't. F1 hybrids possess what is known as hybrid vigor or heterosis. Many F1's are non-viable and die early but you never see these. You only see the ones that survive and these fish have the best growth characteristics, water temperature tolerance, disease resistance and feed conversion. F2's generally have poor survival, poor growth rates and variable morphology or body type. This is probably due to pairing of recessive non-adaptive genes present in the genes of both parents, i.e. two recessive genes popping up in the same individual. F2's of most hybrids are also non-viable so they make for pretty lousy forage production.