What is the reason for stunted growth with fish in lakes?

[Skunked-Rookie]

Is it to do with to many fish and not enough food?

[juggs]

Pretty much. It happens when they're aren't enough predators to keep the small fish in check. Then the little fingerlings eat up everything in the lake and stop growing. So you have a lot of fish that are old enough to be keeper size but ran out of food. That's why a balanced population is crucial to the health of the lake.

[Corey Bechtold]

I assume that you are talking about Panfish especially Sunfish, so here's what I know. Lakes that have stunting or small Sunfish probably had nice fish at one time. What happens to these lakes is that the word gets out about a good bite and everyone and their brother flocks to the lake to take advantage of the seemingly abundant Bluegills they are prone to over harvest. Then what happens after time is that the larger Bluegills (typically Males) are removed and the genetics from these male fish can't make their way back into the system. Therefore stunting occurs. Another problem with some of these lakes is that when the stunted fish start to out-number the bigger males they have a hard time during the spawn fending off the small fish. This is called, sneaking. What happens is that when a big male is about to fertilize the eggs of the female, the sneakers jet into the nest and fertilize the eggs before the large male gets to carry out his genetics.

A lot is being written about this topic right now and there are some experimental lakes that they are playing with to see how to better manage Bluegills and specifically maintaining a healthy population of larger fish.

One thing to remember is that a 9" Bluegill is like a 10lb Walleye. They are trophy fish and selective harvest is a key way to maintain the future of the Bull Gills.

Good luck,

Corey Bechtold

[Bobb-o]

another problem i have heard is that bluegill no longer continue to grow after they begin to spawn, so if all the 10" fish are removed then the 9" start spawning, when they are removed the 8" start spawning, etc.

[CrappieJohn]

This can simply be an issue of genetics, food availability or the water itself. Seldom do we find an answer wrapped up in one specific reason for stunting so it is usually complex.

I like the coorelation of the 9" sunfish to the ten pound walleye. Indeed, both are trophy fish. Since the answer here is not an easy one and fishing is gaining in popularity each year, it is the individual fisherman who can most directly affect the stunting problem.

The prudent fisherman knows what the benchmark is for a "trophy" fish on the lake he is fishing and sets his personal size limit below that length. And then he keeps only what he needs to make a meal if that is a part of his plan. Way too many people keep the full limit just because they can and many fish find their way to the dumpster because of freezer burn.

[katoguy]

9" sunny comparable to a 10# walleye? Maybe an 11" sunny, not a 9er. IMHO

[Matt Johnson]

I'm willing to compromise and say a 10-inch sunny.

An 11-inch sunfish is a brute in Minnesota. I've seen more 10 pound walleyes than I have 11-inch sunfish, and I spend ten-times the amount of time fishing for panfish than I do walleyes. I think the biggest difference here (and a contributing factor to trophy-size beliefs) is that it's entirely possible to get on a pod of 10-11 inch sunfish, where with 10 pound walleyes you typically won't catch one-after-another. So that might put a misconception in some people's minds.

I also think that too many people are quick to judge what the length of a sunfish really is (and are often times off when doing so) without slapping it on a tape measure. A lot of people I've fished with are surprised to see what an actual 8-inch sunfish looks like, same with a 9 or 10-incher. The sunfish they thought were 9-inchers turn out to actually only be 8-inchers. For those who spend a lot of time chasing panfish, there is a big difference between an 8-inch sunfish and a legit 9-incher. I personally think too many people are quick to estimate the length a sunfish before they actually measure it (that’s if they even measure it at all).

While I think reports of 10-inch average catches for sunfish are possible, I just think some of the people who always claim those reports need to reevaluate their measurement techniques. Again, I'm not saying I don't believe the reports I’ve read, I usually give everyone the benefit of the doubt, but it's just that I've experienced and witnessed way too often where people think an 8-inch sunfish is a 9-incher, and a 9-incher is a 10-incher, and so on...

After spending a lot of time on the water and ice chasing panfish, I've made it a point to actually measure all of my sunfish that I think are 8 inches or bigger and I’ve found out that some of my own estimates were off from time to time too. But by slapping the fish down a tape measure, I can be certain of its size and eliminate all the guess-work and false estimates.

If you measure enough sunfish, you will see the differences between even a ¼ of an inch. You’ll notice the difference between 9.5-inch sunfish and a 9.75-inch sunfish, and that ¼ inch does make a difference to those who heavily target sunfish. It could very well mean a few ounces. Being off a ½ inch one way or another is easy to do when judging by sight, but it’s really talking about two totally different fish when comparing a 9-incher and a 9.5-incher. They are each in a class of their own.

I personally think that any sunfish 10 inches or larger could be considered a trophy. Here in MN, a 10-inch sunfish is usually a tall and thick specimen, giving it girth and weight as well. Some specific sunfish breeds will be longer in length and shorter in height, giving it less girth and weight than that of a different specific sunfish breed. Keep that in mind as well.

Either way you look at though, a 10-inch sunfish is a great fish!

Good Fishin,

Matt Johnson

[katoguy]

A 10 is definitely a nice catch. I got several last week (measure board). You are right on the 'getting on the school of big ones' theory, but I have caught bunches (hundreds probably) of 10"ers and zero 10 pounders. Darn things are avoiding me. Maybe I should leave my half ounce jigs and flipping sticks home more often. Not this weekend, though.

[Warren]

OK , Try this one , is not a Lake really a closed System, Like an Aqauarium?

I saw a study that Michigan State used a quart bottle to run food & fresh water in it, that fish filled the Bottle. How many of us had an aquarium and hardly ever changed the water and just topped it off periodically, was too many fish and they got stunted, runt's. Or those uf us that bread Angel Fish and knew to feed and change the water daily , we say those fish explode in growth.

Big Fish = Lot's of Food & Fresh Water

The truth is that it's in the excess quantity of the hormones in the feces & urine, ie too many fish for that body of water.

Like the above the System got out of check (balance)and the excess hormone's in the water is mother natures way to fight for survival.

I would bet it a major fish kill and the system cleansed itsel back up a Lake could over time get back in balance .

[CrappieJohn]

Warren....

Welcome to FishingMinnesota.com!

Thanks for the input on this one, but I would suggest that the natural dilution rate in a natural body of water would not allow the waste from fish to become a factor in determining size.

Stunting will not likely be the result of a single factor in wild water. In a clinical or controlled system intentional manipulation can give results which can be misleading....kind of like a statistic.

All waters are not created equal when it comes to potential for supporting large fish within a specific specie. I know of lakes of several hundred acres where crappies are just not going to exceed that 9 to 9 1/2 inch range eventhough the forage base is more than adequate to support a bunch more additional growth. And I know of a couple paltry little sandpits that hold some huge brutes with little in the nature of minnow life. These larger fish in the pits are not near so numerous as those little guys with far better growing conditions. In the pits though you can still catch a few smaller fish to support the idea that they are pro-creating.

When I mentioned that 9 inches was the threshold for a trophy sunfish, I was not clear in why I stated that size. As Matt has offered, when you get to 9", these fish are beginning to see the slower growth rate kick in. Instead of an inch per year they may be only seeing 1/4"/year. Getting fish to over 10" takes a tremendously long time even with far superior genetics on their behalf. Most of the waters around where I live will show sunnies of up to 8" pretty easily. A few will give up 9" fish on occasion. Only a couple have shown me 10 inch fish. I am very aware of what each of these local waters can yield size-wise and I adapt my personal slot accordingly. This is something that we all should be doing. By knowing what is a trophy fish in any body of water you intend to fish is the single most influential thing we can do to protect the trophy fish in any given body of water.

Again Warren, welcome to FishingMinnesota.com! We are always happy to see new names and hear new ideas.