Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Danger Stocking Bluegill in Existing Lake ?

I have posted previously about a 35 acre lake our fishing club leases. It produces very large crappie but the bass are numerous and mostly all small, 8"-12". They have been decreasing in average size over the past 10 years. While we are trying to "thin the herd on the bass", I am sure our efforts are not enough to make much of a difference.

So the idea was raised to introduce bluegill to hopefully give the bass some increased forage to eat and hopefully increase their size. Like to get some thoughts on this - especially since this could be an irreversible move we might regret ?

If you introduce another forage species for LMB, 2 things "may" happen.. pressure will be relieved on crappie to the extent their growth rates suffer because numbers will increase-size will not and if you continue to cull LMB at that 12" range, the BG are going to explode and take a lot of your carrying capacity away.
I see 2 choices.. 1 is maintaining a large panfish situation which would be the Crappie and BG, or 2, cull as many LMB from 8-14" as is possible and grow larger bass.
Crappie can be a formidable predator themselves but the balance of LMB and Crappie can be difficult.

To be sure, it will be irreversible. Whether the move would be regretted? That is unknown.

I would consider at least this question, does the club enjoy the fishing as it currently is? Some might argue that the water is out of balance because the LMB are not attaining their potential for growth. Another way of looking at this is that everything has reached a unique balance for your lake that doesn't happen in many others. There is just enough energy consumed by LMB to support their biomass and they weigh just enough individually to sum to that biomass. The same can be said of the crappie. So the biomass of each species is in balance with the foods available to them AND the biomass is in balance with the product of the average weight of each species and their population number.

What you are experiencing is not the balance achieved in all water but unique to your lake, in your location, under the existing exploitation practices. Some might find such water great to fish where catch rates are high for small LMB and BCP are dandy sizes. I think the question of whether something needs to be fixed is subjective and should be arrived as a consensus of the club.

PondStar, you mentioned that:


I would just say this. It does make a difference, but this is also a balance. Suppose you have 40% mortality this year including the exploitation. Neglecting recruitment, this would allow an increase of average weight by 40%. So this might increase the average length from 10" to 11". But this neglects recruitment which will slow the growth.

On the other hand, can you add 40% more energy consumption by LMB by adding an additional an additional prey species? If so, then they could grow from an average length of 10" to 11" on that extra ration without the mortality. But this neglects recruitment which will slow the growth.

We truly underappreciate the role of mortality for fish growth. LMB grow at remarkable rates and at 10" they have the capacity to quadruple their weight (in a year) at maximum potential for mid latitude climate. But to grow at that rate the 10" LMB must consume 4.3 times the forage it would have to consume to remain 1/2 lb. Relative to using mortality to increase consumption per individual, that is a mortality rate of ~ 80%.

Point well taken, harvesting modest amounts of LMB will not boost their size much ... but likewise ... adding forage probably will not either unless it affects populations.

If you add BG, you should expect a few things. You should expect growth of crappie to slow as BG populations increase due to competition (unless lower BCP recruitment can compensate). You should expect recruitment of the LMB to decline. Over several years you will have fewer LMB. This could have a positive effect on LMB growth provided they are able to consume as much energy as they are consuming now. There are other unknowns, for example, do you have another forage species (eg a minnow species) contributing to forage production that will be adversely affected by BG. Species interactions are complex and the result of combinations vary. It will be difficult to predict.

Snipe is correct, if you add another forage species then that will take predation pressure off of some of the crappie, which will allow more to survive, which will reduce the overall size of the crappie due to less available food per crappie.

It's impossible to recommend a management plan without knowing the bathyspheric profile of the lake, the lake's fertility and what cover/habitat is in the lake.

If I was managing the pond, and the goal was to grow larger bass at the expense of the large crappie, I would hire an electrofishing boat to electrofish the pond and remove all of the under 14"-16" LMB that are shocked up. Then add a bunch of bluegill providing there was habitat to allow them to flourish. You will have to have a large budget for this to be a success. Without a sufficient budget, you are wasting your money.

Now if the majority of the members like catching the larger crappie, and a minority of members want the larger bass, then do nothing. It will be VERY expensive to turn this around to do both, but not impossible.

Thanks so much for all of the insight .............. it really apperas to be quite a bit more complex of a propositon than first meets the eye. We have given little thought to the fact we might be impacting the size of the Crappie by this move. The big Crappie are a hit with the fishermen as local public lakes do not have crappie of the size we see in our lake.

To answer one of the questions - no additional forage as far as minnows go, but did introduce crayfish two years ago

Will share your thoughts with the Board of Directors

If you are catching crappie and everyone is happy catching them then I wouldnt bother adding another species, you have trout as well right. I put sunfish in my lake and they exploded like mad this summer, they spawned and were sitting on nests from june to august it was crazy...

here is a video of the sunfish, really fun to watch these little guys all over the place but Im going to have to get some LMB in there to start managing numbers.



and

Nice work on the videos ! There are a bunch of small LMB in those videos as well as BG and PS.

Hey thanks! I just caught a rainbow trout through the ice a couple of days ago, was about 14 inches long and it had a ball of .75 inch long sunfish in it - must have been 100 of them. The trout are really putting the hurt on the sunfish but thats not a bad thing to be honest - I was worried about an over population of sunfish. I've also taken video of the trout while sight fishing in an ice fishing tent - they are insanely voracious and come in like torpedoes....really cool to see.

This is awesome information!! Awesome!!! Trout eating bluegill in Oh Canada....!!!!

When Snipe finally develops his saugbows, do you think he will be able to get them approved for sale in Canada?

Well, if Oh Canada becomes the 51st state, then yes!!!

But really, knowing that a trout of that size is cleaning up on <1" bluegill....that's almost ground breaking in my opinion.

I can hardly wait to visit First Nation casinos in Nunavut.

Ill take pics next time...or video. I watched the trout through the ice in about 2 feet of water plunging into the thick weeds, took me a while to see that they were going after the little sunfish.

We wont be the 51st state but you can have British Columbia and we will take Alaska.

We wont be the 51st state but you can have British Columbia and we will take Alaska.[/quote]

We would have to work out some kinda trade like that because we don't have room for another star on our flag.
But we would much rather trade California, Alaska is pretty neat with some really great fishing!
They are gonna need some serious rebuilding tho, there's a lot of houses disappearing even as we speak.

We would have to work out some kinda trade like that because we don't have room for another star on our flag.
But we would much rather trade California, Alaska is pretty neat with some really great fishing!
They are gonna need some serious rebuilding tho, there's a lot of houses disappearing even as we speak.[/quote]

Hmm, I kinda figured you'd throw Cali in there but that's like trading British Columbia for the British Columbia...unless we can get Cali without the inhabitants....then it's a deal.

This is good spirited negotiations.

I'd like to offer up Trenton, New Jersey in the deal.

I'd refuse that, but you can have Toronto.

I'd trade the District of Columbia for British Columbia or the Yukon Territory! I'd even throw in California to sweeten the deal.

What if we added Camden, New Jersey?

OK- so who do I throw in the lake for taking this so far off topic ??

LOL I think Tinylake started it!