What Determines the Average size of fish in a lake

Yesterday I decided to try a new Lake that I’ve never fished before. I told a friend who has lived a long time in this area, and has fished almost ever lake around here where I was heading. He said ” don’t waste your time – all the bass in that Lake are around 12″ and you will struggle to get a 14″ fish ” I asked him the last time he’s fished it and he said 10 years ago or so, but it has always been that way. I thought who knows it may have changed. Well after catching 4 12″ fish on my 1st 4 cast and another 80 -100 fish all in the 10-13″ range I had to agree he was correct. This is one on many lakes I know like this. The fish just never seem to get bigger in them. I have noticed that most of the lakes that have this problem ( for bass anyway ) seem to be deeper lakes with rather clear water. I wonder if that may play a role. Some other thoughts are that the bass just get stunted, To high of #’s and not enough harvest, Over harvest of larger fish , Poor food source ( Don’t think so – most of the small fish caught were really fat and seemed to be feeding well ) Poor Genetic strain. What are your thoughts of why this happens. I think that taking more fish out of these water can’t hurt, and I believe it may actually help. I know that most people either think that Bass are not good eating, or God NO – Don’t keep a bass to eat. In the last few years I’ve started to keep a few bass early in the spring or late in the Fall to eat ( Mostly target 12-14″ ) Mostly from these waters where the # of small fish seem to be really high. Its my opinion that bass out of cooler water are just as good eating as any other fish. In fact I prefer them to all other fish when baking them in the over or on the grill. You cant beat that white flaky meat. I’m curious on what your thought are on this issue.

Obviously the DNR’s fault in all cases.

It would be interesting to see a map of that lake. I always look for big flats areas. 4-10 foot depths with swampy edges and lots of weeds. Those kinds of areas crank out Bass food by the ton. If the shore drops off quickly all around the lake, life is a lot tougher.

Catching 80-100 of anything sounds like a fun day even if they weren’t very big.

S.R.

For large mouth, I wonder if a lake like that is partially too cold if it’s really deep and being up north?

I’ve always found some of the best bass lakes to produce size are shallower west of metro lakes that aren’t very big and have a lot of vegetation.

Also, similar to Pike management I wonder if too many fish causes poor size structure.

Forage, biomass, competition, predators, cover, all play a role. I think food is the biggest issue. If the lake is full of HUGE numbers if 11-13″ LMB, they can gobble up most of the food in a lake. There simply isn’t enough food to allow for larger fish to sustain themselves.

Look at the Mississippi, TONS of food from a variety of sources and growth rates and population are very strong.
Clear, cold, infertile lakes in the arrowhead region have very slow growth rates but fish can grow larger because there is some food but relatively low biomass chasing the available food.

Lakes like Mille Lacs with bugs, perch, etc can support a ton of biomass, but the lake can easily get out of balance.

Steve Root wrote:

It would be interesting to see a map of that lake. I always look for big flats areas. 4-10 foot depths with swampy edges and lots of weeds. Those kinds of areas crank out Bass food by the ton. If the shore drops off quickly all around the lake, life is a lot tougher.

Catching 80-100 of anything sounds like a fun day even if they weren’t very big.

S.R.

Steve see PM – This lake is rather Deep – They stock lots of Trout in it I’m told. The shoreline does have rather steep Breaklines – There were several midlake humps that did hold most of the fish I caught. It was a fun outing – It just would have been nice to catch a few Bigger fish, or at least feel like you had a chance at a bigger one

I’ve often thought the same thing about Crappie’s on Lake Waconia, but some pigs get caught out there as well. I think it’s more about finding a different area for the big fish, since they wouldn’t want to compete with the many smaller fish for food.

I agree with BigWerm, I fish a small lake up north that has a tone of 14″ walleye, first time fishing it caught 50-60 fish in just 2 hrs all the same size. My brother then was saying this lake would be a blast if there was a chance at a bigger fish and right then he pulled in a 24″. The 24″ and the handful of 17″+ fish we have pulled from that lake were in a completely different area and structure type than the smaller fish.

Especially with bass, the food sources and water temps especially play a huge role. I read an articlea year or so ago, comparing southern bass to northern bass and (the exact numbers may be off here), a 5 year old bass in Texas could be a 5-8 lber while a 5 year old bass in say MN would only be around 2-3 lbs. Warmer waters temps for longer mean more time for the bass to eat. Colder means less time for the bass too feed up.

In the same region, I would think it would be all about food sources and how much competition among predatory species for the food sources.

I’m with you thumper 12 to 14 inch bass are a tasty meal especially out of cold water

Way too many variables to figure out the why and each lake is different. It all comes down to ecological balance.

Generally speaking, the higher the population of a species, the less likely there will be larger fish.

The ponds I fish for bass have low populations, but great quality fish. They are incredibly ecologically diverse as well. In the retention pond, which at first glance would look devoid of anything, there are periods throughout the year that will kill off fish due to harse living conditions.

Great thing about this sport and this forum is you can come up with theories, heres mine: Bass mostly eat bluegills here in Mn anyway, most lakes have plenty of bluegills, to grow nice sized bass you need nice structure and low to moderate competition. Wait make that excellent structure. If the lake has lots of good structure and many good spawning areas you will have lots of 2lb fish. Big ol bass cannot compete with all those fast moving medium fish. She can push out those fish and monoplize a nice ambush point if the lake has them. BTW muskies also like those spots, ever see a big gash on the side of a big bass in lakes where skis are present (yep another theory)

Might be a little different response than you are looking for, but I have heard one good piece of info regarding this topic. Or at least I think it is a good piece of info.
And that is that a lake can only support so many pounds of fish per acre o whatever measurement you want to use. The point being that there can be a lot of smaller fish or fewer bigger fish. And the special lakes have the right mix of both. This is also cyclic as most everything in nature is. I heard this from somewhere awhile ago, and based off of hearing it I thought it was very true. Of course I have no data to back that up…lol

Had a fisheries guy tell me that they get pressured to stock certainlakes every year with walleye. He said that it would be better to stock every other year. Lakes that have natural spawning have quality fish when some spawning years are succesful and some not. Also great structure helps for bass.

Predators, Forage and Location

Comparing bass in Texas to bass in Minnesota isn’t really a fair assessment. Most bass down south are a completely different genetic strain (Florida strain) than they are here (Northern strain). If there’s trout in it, its probably not suitable to grow big bass. Too clear, too cold, too deep, and not fertile enough.