Size Structure

[WasteManagement]

I have permission to fish a private lake in northern WI. It contains largemouth bass and bluegills. The average size of the bluegills is 10in. I catch almost all between 9 and 12 in. The large mouth are fun but are all close to 2-3 pounds size wise. But always look thin. Both speciaes are jam packed. The people keep the lake catch and release only. Like a bass every 10 min when moving and during peek times every 5th cast. The only time you ever see a smaller sunny caught is when you fish directly next to a dock poll.

If i were to elimintae several bass. With permission. Do you think the bass would thicken and grow? Or would there be several more small sunnies taking over? Would a 5 pound largemouth be able to eat a 12 in sunny? And make the sunfish hard to catch. The people have kids and grandkids that love catching fish all day and i do not want to ruin that.

The lake is a blast. Its only 30 acres or so. Should i put my giant bass on hold and keep it like it is. Or does it make sense to take out several bass and hope the remaining ones grow.

[Nick Kuhn]

You likely couldn't change the size structure yourself. It's more of a forage issue than an overpopulation one. If you took some out, more would quickly replace them. It would be better to enhance the forage, which likely would mean getting more perch/minnows into the lake.

[goblueM]

personally, i think the giant bluegills are much more valuable because they are tougher to come by - you can catch nice bass almost anywhere

I wouldn't mess with it just for the fact that it seems like you have an awesome fishery and wouldn't want to disrupt it. HOWEVER, it is likely that you would have to remove quite a few bass to make a difference in the size structure

largemouth cannot not eat large bluegill - that is why there are so many of the larger ones, the bass only prey upon smaller bluegills (likely < 5 inches TL). This is why there aren't many small bluegill in the lake, their numbers are kept down thru heavy predation, leaving the survivors plenty of resources to grow large

Since the bass are skinny, there probably isn't a big enough prey base for them to add weight and grow longer. Options to help them get bigger would be reducing their numbers substantially so there is more food for each remaining bass, or to increase the prey base. Both actions would probably have effects on the bluegill size structure though

[Superduty]

From a fisherman's perspective, I would comply with the wishes of the ponds owner. Afterall, they gave you permission to fish their lake. Don't ruin a good thing.

From a fisheries mgmt perspective I am intrigued and jealous of your/their position owning a pond like this. (I have a fisheries mgmt background and career options have led me elsewhere.) There are a lot of unaswered questions as to why the bass are relatively small and the sunfish are large. It might be as simple as the age of the bass. If they were all stocked at the same time they might simply be young and still growing. It takes many years for northern strain largemouth to get to trophy status. If growth rates are good, I wouldn't change anything. Start with determining the age of the bass and go from there. Other factors involved would be habitat diversity, forage base, total bass population, recruitment(spawning success), harvest, angler ability even comes into play if this is your only means for sampling the size of the fish,and probably more that I can't think of off the top of my head.

[WasteManagement]

It is an old lake. No inlets or outlets. Spring fed. Private property surronding the lake for at least a mile in every direction. You cannot be on "hike" and not know you crossed onto private land. No motors and no outside canoes. I clean my lures before i cast.

I have fished it for 10 years and it has been around for at least 20 years past that. Fish age is just a matter of living or not.

The structure. It is mostly sand with a little bit of weeds in one corner bay. I can almost cast across that section. And it does not go out to far length wise. A cast and a half. The rest of lake is pretty much open. Which works out nice. If you cast a bobber and a worm out you are going to catch what ever a 2-3 pound bass cannot eat. The bass hammer the worms pretty good too.

As for shear numbers. I catch a bass about every ten casts in variuos shore locations and have better luck on the lake it self. It is common to see up to three of these guys patrolling around on sunny days when they go over the beach areas or through the shallow bay. Also seeing a follower as you real in is common. Of course when we over fish areas the fish get shy. Average day or fishing moderetly 20-25 bass.

The sunnies. At the power hour at dusk. Bring them in as often as you can get a worm on and a good hook set. Thats in a couple locations.

[Superduty]

My quick and dirty assessment would be that the bass are eating a high percentage of the small bluegills. The few surviving bluegills have little competition for the food source-probably zooplankton a good part of the year. The result is large adult bluegills that are too big(for the most part) for the remaining predators to eat. Without another forage option for the bass, this could be limiting their growth. Harvesting bass in such a case would leave a smaller bass population with more forage/bass if you follow me. In a 30 acre pond, I think a few talented anglers could easily kill enough bass to have an impact. This would also probably result in smaller adult bluegills over time. There would be more adult bluegills using the same forage base. Less forage/bluegill.

Another factor that crossed my mind regarding growth rates for the bass had to do with the lack of vegetation or any other type of cover. Bass growth increases to a point as structural complexity increases. In other words, largemouth bass need cover of some kind to be more efficient in feeding. They are not the best open water predators.

[goblueM]

kinda lines up with my previous quick and dirty assesment, you copy cat

[WasteManagement]

I go about 6'2, 6'3 and am unfotunitly 280 in that pic. That is the average. Mostly a big bigger but few any smaller. The wormly looking stuff on the side is just sand.

Again average size for a sunny. Pic is not the best for size. Just took it for myself.

[Nick Kuhn]

That bass looks pretty young and is about normal weight for a bass during the summer months.

[WasteManagement]

The body looks good but the back is narrow. They look like giant head bass on slim bodies.

[TurnUpTheFishing]

personally, i think the giant bluegills are much more valuable because they are tougher to come by - you can catch nice bass almost anywhere

My thoughts exactly.

Sure it would be nice to have the best of both worlds but come on now, 12" bluegills, that has got to be a blast!

[goblueM]

got a load of Neascus in there too, looks like. if you are interested, look on Google Scholar for some literature on bass and bluegills in ponds... its widely accepted that bluegill size generally gets much larger as bass densities increase

[Superduty]

Didn't mean to step on your toes earlier goblueM. I should have read more than just Wastemanagents response before I posted. I guess great minds think alike!

[goblueM]

hahah i was just giving you a hard time super duty, and you said it more eloquently than me anyways

sure wish i had his "problem", someday I'll have my own small lake to manage