Management Question

[thedarkarcher]

I fish a local farm pond that for years produced trophy bass, crappie, bluegill and some 15+ pound channel cats. i didn't fish the lake in 2007 because i had moved to wyoming but when i returned last spring and began fishing it again i was surprised to find i couldn't catch a bass over 15 inches and even those rare...most bass were anywhere from 6-12 inches or less. the crappie were still there in numbers with an occasional very large fish but most were 7-12 inches with quite a few smaller fish as well. plenty of gills as well but nothing huge like they used to be. this change came about over a single year. my question is...could a fish kill have taken out just the larger fish? what might have happened? now that the crappies are extremely over populated is the only solution chemical renovation, or can a heavy harvest on crappies and gills give the bass a chance to come back?

[Chad]

Great post, Dark. I love a good farm pond mystery!

I'm just an amateur, but here are some of my thoughts.

YES! a fish kill could have taken out just the larger fish. In fact, a dip in DO is going to affect the bigger fish before the smaller ones. Check out this kill post from Teeg and I at a farm pond last spring. You'll see that we found 28 dead bass - all MA class, and only 3 BG.

Teeg and I surveyed the ice-out scene at the pond.
I pulled on waders and got personal with the dead fish. Teeg snapped some pictures. I asked him if he got some good ones and he said, "Well they're of you and dead fish, so..."

Here's what we found dead and washed ashore. It was a little painful to see all those beautiful bass.

LMB - 28 dead in the following lengths (all fat): 19", 19", 21", 20", 20", 18", 20", 19", 19", 20", 20", 20", 21", 20". Another 14 were roughly that same size/class, but unmeasurable.

BG - 3 dead in the following lengths: 3.75", 3.75". 1 BIG BG head that we suspect came from a MA-class BG.

Bullfrogs - 20ish dead, most big, some that made you say, "Wow, look a the size of that bullfrog!"

Leopard frogs - 2 small, 1 the size of a medium size bullfrog.

Filamentous Algae - Yes, mat on the pond bottom.

Monster Bass...

Second, the guys over at pond boss have discussed the issue of crappie in farm ponds. There's a wealth of information over there about the subject. Bottom line is this: Recruitment of crappie (the number of fry that survive) is highly variable, to the extent that consistent management of a pond's fish population that includes crappie is a mystery. You just can't count on a stable population size of crappie. Any given year, you could have a population explosion that could quickly translate into a population of slow growing yoy crappie and bluegill because there is not enough available food.

The way I understand it, that could quickly hurt the survival of your larger bluegill as well since a part of their diet will continue to rely on plankton even as adults. Plus, once those yoy bluegill reach a certain size they will compete with the larger gills for aquatic insects. I'm not sure to what degree aquatic insects make up the crappie diet, but to the degree that they do that's going to be less food to go around also.

Now, those big bluegill didn't get to be big by being the last one in the feed line, but even so imagine this: You have a high school class of 100 students who all depend on the same lunch room to survive. Let's say there's enough food for exactly those 100 students, and that's it. Now add 1,000 junior high kids from a school that was closed, and envision the lunch room without any adults - no rules. What would happen? Starvation is going to be a reality for a large number of students (sorry, I just realized this illustration is a little morbid ). You'd expect the seniors to use their size and superiority to complete for food, but for each senior you'd have 30 plus junior highers swarming around him steeling his food. It's not going to take a full year of that level of competition over food to see dramatic changes in all ages and size classes of this truly unfortunate school.

Now all of that isn't going to hurt your population of large bass... at first. In fact, it would give them more fish to eat. But, it might make them VERY hard to catch since there is so much food for them. And, their daily feeding period may also be VERY brief - open mouth, fill stomach. Starting with the next age class of bass you're going to see a dip in bass recruitment. Over time (and I know you're pond isn't at this point yet) you'll end up with a pond that only has big, old bass in it, and their numbers will be declining with age mortality. At that point, you're in big trouble since adding bass or a chemical kill are your two solutions, and adding small bass won't help because small bass need the same food source as all your stunted pan fish in order to grow up.

Dark, I'm afraid you need a good number of adolescent bass and the sooner the better!

One other thing for us to think about, and now I'm really out on a limb (like I wasn't before ). I know that wipers are really bad at eating bluegill; they're just not built to hunt structure in the shallows. But is there any research on the use of wipers to bring into check an overpopulation of crappie in a smallish pond?

It seems like wipers may be more suited to successfully feeding on crappie than gills, and you wouldn't have to worry about them reproducing like you would if you were to add flatheads or other predators. Just a thought.

[thedarkarcher]

thanks a ton chad. from your analysis i have some new questions...
i'm guessing there was a fish kill and the big bass died. they are just gone. now, there are still a lot of bass but they are small, most of the crappie are bigger than the bass. the pond is just chock full of fish and the lack of size in all species makes me think that they already stunted. do the bass have a chance for normal growth in these conditions? would heavy panfish harvest give them a better chance? and lastly, if the bass grew up optimally would they cut down the high numbers of panfish enough that all 3 species could start being balanced enough to produce quality fish? eventually? i'm sure this happens to other ponds and i'm wondering what will take place if there is no intervention as well?

[Chad]

A few more thoughts.

First, you should re-title this thread and turn it into an ongoing blog of your management efforts at the pond. Include pictures and reports over the course of the next couple years as you try to better understand and correct the problem. We would all learn a lot.

Second, spend some time with Nebraska Pond Management - 96 page resource from NGPC, consisting of five chapters that provide information on pond construction, environmental modifications, stocking, management, and potential maintenance problems. Excellent!

Third, consider contacting Jeff Blaser, NGPC Private Waters Specialist. If you call him right now, you could get your pond on his schedule for spring electrofishing. If you haven't already checked it out, the "A Sarpy County Farm Pond" thread has a report on a spring electrofishing excursion with Jeff. You will learn WAY MORE about your current population, and be able to get an expert's perspective on what could be done. In fact, I asked Jeff straight out, if you were managing this pond, what would you do. His answer pretty much shapped our current plan, and he gave us 2 or 3 fallback plans if the 1st was unsuccessful. (Note: take lots of pictures!)

Originally Posted by thedarkarcher

do the bass have a chance for normal growth in these conditions?

Probably better than "normal." As Daryl just said on another thread, "The management strategy recommended for producing big bluegills mentions an abundance of small bass, 'most less than 12 inches'. It sounds like your bass have an endless smorgasbord.

Originally Posted by thedarkarcher

would heavy panfish harvest give them a better chance?

I doubt it. Even with a seine net, I doubt it.

Originally Posted by thedarkarcher

and lastly, if the bass grew up optimally would they cut down the high numbers of panfish enough that all 3 species could start being balanced enough to produce quality fish? eventually? i'm sure this happens to other ponds and i'm wondering what will take place if there is no intervention as well?

Maybe, but why did it happen in the first place. Did you have a kill? If so, it may be likely to happen again. There are just too many unanswered questions at this point, IMO. I think you need more data. I think your first goal should be to better understand why the fishery changed. I would be out there right at ice out to see if you had a winter kill (like we did). I would do the electrofishing thing. And I would fish it a bunch more. By the time you finish those things, you'll have a much more educated position from which to draw up a manegement strategy.

[thedarkarcher]

How deep is the pond? What is the water quality like? How much aquatic vegetation is there? Does anyone else fish the pond? How much fishing pressure is there? Were there any drastic changes in water levels, water quality, habitat conditions?

There are several things that could have caused a drastic change in a short period of time. Yes, a fish kill could have, but so could excessive harvest of bass or perhaps some changes in habitat or water conditions.

The best strategy now depends on what caused the change. If there was a fish kill, then the pond may have some bigger issues that need to be addressed or else you risk "deja vu all over again".

Harvesting bluegills and crappies may make you feel better, but it may not help that much. Those panfish are capable of reproduction at a small size and extremely young age. Controlling the numbers of panfish needs to occur when they are still very young, less than 1 or 2 years old. Once they become over-populated it can be almost impossible to get back on top of them, and the easiest solution may be a chemical renovation and re-stocking.

Daryl Bauer
Lakes and Reservoirs Program Manager
Nebraska Game & Parks Commission
daryl.bauer@nebraska.gov

P.S. Please feel free to share this message with others.

[thedarkarcher]

thanks again for the resources and info chad. i think i will begin working on this and give some updates on what i find. to fill in some more info...
i've fished the pond for about 10 years and this has never happened before. although those few years we were experiencing drought conditions brough the water level lower than i've ever seen it. max depth is about 11 feet along secondary contour lines parallel to the dam and that channel maxes out at about eight feet along the other shorelines. the lake receives drainage from about six other ponds above it...so it has a constant supply of food coming in through the summer. the water is usually a bit stained but never muddy...there is always at least a couple feet of visibility. also, there is very limited harvest on lmb, while crappie have been harvested often throughout the years i've fished it. aquatic vegetation that reached the surface seemed to decline for some reason during the dry years and there has been a noticibly smaller amount of vegetation the past 3 years.

[jarredbehrendt]

What does the land that feeds these lakes look like, is it farmed or CRP, etc?

[thedarkarcher]

its pretty much all CRP....i don't think there is any crop runoff at all.

[jarredbehrendt]

Hmmmm, Was it cropland before? Or is the decline in vegetation due to it being siltier or having lower visibility in the spring maybe?