Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations NE Chad's Pond: ELECTROFISH COMPLETE

Hi everyone... new member, thanks for the great resource!

Some friends and I have recently started managing a 5 acre pond. I'm new to this so it should be a good learning opportunity.

My question is, what should we be doing while there is still ice on the pond?

We ice fished it once and observed a large population of small, malnourished bluegill that appeared to be suffering the effects of low DO levels. The water was also turbid under the ice (looked a little yellow).

We plan on collecting a water sample this week for a jar test. Anything else we should be doing right now?

Keeping snow off of areas of the pond is helpful to let light in which I think helps with water quality?

Don't fall through the ice. I hate when that happens.

Does the pond have sufficient structure? If not, this could be a good time to place cedar trees, etc. I'm not the biggest fan of abundant snags however.

Not sure, Bruce. What is evident with the ice on is a good number of stickups in the southern end of the pond. The owner hasn't told us that any other structural elements were present before it filled or added after that.

We will have to asses that this spring/summer and perhaps plan additions for a year from now, if needed.

Is my assumption correct that now is a good time to do the jar test? If it's turbid under the ice and settles out in the jar, it pretty much has to be a carp/bullhead problem... right?

Went out to the pond this morning to jig up one of the few lunker bass that must be in there along with all the stunted gills, and to conduct the jar test. No Bass but a beautiful sunrise nonetheless.

Scott filling a jug.


One of the jars... doesn't look as turbid as I expected


What's this swimming in my Jar?
Like I said, I'm new to all this... zooplankton? A good sign?
http://www.youtube.com/v/NnoP00j_wyc&rel=1"
(Sorry, not sure how to embed videos on this forum.)

Definitely zooplankton! Always a good sign. Another term for zooplankton is "groceries".

I'm hoping that Bill Cody can get a look at that video. For a "you-tube" video I thought the quality was actually quite good.

It will be interesting to watch that jar over the next few days. I'm sure you already realize that this water may be as clear as you every see it. One interesting phenomenon I've seen on turbid mid-western ponds is that they often grow a mat of filamentous algae on the pond bottom during the winter because it's the only time of year that there is adequate light penetration. This filamentous algae sequesters nutrients and can keep the water really clean looking until the first big rain or wind event after ice off. Then the ensuing decrease in light level causes the demise of the filamentous algae on the bottom. It makes for a pretty bad combination of suspended sediment and dying microphytic vegetation.

What is that finger like structure traversing the pond in the upper quintile? Almost looks like a little sediment nutrient dike. I also see you've got some nice filter strips to protect you a little from the influx of silt and attached nitrogen and phosphorous you're getting out of that row crop activity.

I think the key to ponds like this is to do what you can to keep water clean in the spring, which may not be much, and then to maximize the growth of your fish during the other three seasons. It can really be a challenge.

How do you Nebraska guys get all of your aerial photos?

Sunil,

If you're talking about the pic in my signature, it's from Google Earth.

Bruce,

Thanks for the reply - interesting info! When you say, "filamentous algae sequesters nutrients," are the "nutrients" phytoplankton? Are phytoplankton required to produce zooplankton?

Also, should the presence of that zooplankton in the jar tell me anything definitive about the bottom on the food chain?

BTW, there are two finger-like structures in the south end of the pond. The one headed south is visible. The one headed west is obscured by trees. Both are old seasonal creeks that used to flow into another creek each spring before dumping into the Platte and making tracks for the Missouri.

Some of the limiting factors for plant growth, such as phosphorous and nitrogen are taken up by the filamentous algae, which makes them unavailable for other plants, such as single cell algae (which give the water a greener tint). Phytoplankton are microscopic plants, most of which are too small to be seen with the unaided eye. They use these nutrients to complete their life processes, and in turn are utilized by many types of zooplankton for nourishment. Zooplankton are microscopic animals which are then in turn eaten by other zooplankton and small fishes.



Yes, it tells you that the bottom of the food chain is indeed present, and judging by the activity in your jar it appears that it is thriving. This is a great sign. Now you need to learn to manipulate the fish community so that it doesn't overharvest this valuable resource.

After spending some time reading and rereading your response and crossing it against wikipedia and other sources... I finally get it - or at least think I do.

sunlight + nutrients = phytoplankton.

Once a pond has phytoplankton the Lord says, "Let there be zooplankton in the pond." (Please note: I'm not really sure about this part. )

Together, phytoplankton and zooplankton (plankton) create the base of the food web. Phytoplankton are eaten by zooplankton, other aquatic organism (e.g. worms, snails, and insects), and some fishes. Zooplankton are eaten by other zooplankton, aquatic organism, and some fishes.

Nutrients are supplied through the natural byproducts of the food cycle and external sources, primarily runoff, which also adds sediment. An over abundance of nutrients can create too high of a density of plankton, blocking sunlight. Sunlight can also be blocked by suspended sediment. Reduced light will lead to decomposition of plant life causing oxygen sags, which can lead to fish kills.

Ice up, allows turbid Midwestern ponds to clear. Plankton and other plant life then flourish, hence the mat of filamentous algae. After ice out, runoff and wind combine to create a lot of suspended sediment, limiting sunlight, leading to decomposition and an all-around nasty environment that won't improve until the ice comes back.

But would that cycle lead to the problem I have? A once balanced fishery that is now overrun with gills?

And..

Are improvements to that buffer strip around the pond the key to keeping the pond cleaner during open water?

I think you are a good student, and an even better writer.

You've pretty much got it nailed.

Your imbalanced fishery can be managed with most impact by harvest, and feeding. This is how you can add wealth in the form of additional calories, and redistribute that wealth, by limiting the number of mouths fighting for the calories.

The best way to determine which fish need to be harvested is to report on the size distribution of fish, relative weights of the various sizes, and the types of fish present. This can be done through angling, or more specifically through netting or electrofishing.

NE Chad summarizes a recent lesson:

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Mastah Bluce provides the nod:

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I don't care if NEC can read Bski, Porturalian, or any other twisted PB language derivitive. That little morsel of summary should be reviewed, tweaked where needed (if it is even needed...?) and saved for the Fish for Dummies section that will someday be constructed in the forum.
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Good show, NE Chad.

Welcome to a great pond managment forum.
Bruce is providing great basic advice. He professionally manages numerous ponds in NE.
Zooplankton in the jar were on the medium-large size range. I could not see their movements well enough to determine which of the two main groups was more common. Generally the larger forms are usually less abundant when lots of small overabundant bluegills are present. The larger forms are often near the surface when snow cover is present and during evening. Thus you were able to collect significiant numbers of them in your homemade shallow water sampler. When zooplankers are concentrated in clouds, the panfish will often follow or seek out these zooplankton clouds and feed heavily on them irregardless of the water depth. Overabundant small bluegills tend to overharvest the larger "more beneficial?" zooplankters.

Pondwater in a clear jar always appears a lot more clear in the jar than it does when one looks at the water in the pond. If the pond recently had a freeze - thaw runoff- freeze cycle, the water would tend to be more turbid even after a few weeks after the runoff event. Typically, water clarity under the ice will be the clearest of the entire year - exceptions do occur.
You ask - "If it's turbid under the ice and settles out in the jar, it pretty much has to be a carp/bullhead problem... right?" Not always. In many cases carp/bullhead, crayfish are very inactive under ice cover. The turbidity caused by their activiy usually does not become prevalent until the water reaches 45-50F and above. Occassional activity of winter hibernating muskrats can cause turbidity that persits for several weeks under ice cover.

Use this winter period to do homework of reading old posts and topics on this forum. Maybe a couple of our good "librarians" can locate a couple of good topics about fish sampling for you.

One task you can do this winter is take some soundings of the depths in various parts of the pond. Although a depth finder in open water will also work for this task. One of the main tasks for you fellows this spring and summer will be to sample the existing fish populations of your 5 ac pond. It is not unusual for a LMB-BG pond to become bass scarse and BG overabundant and this may be the case with "your" pond. This is usually due to several sessions of improper fish harvest. Fishing, trapping and seining the shallows are the main ways to assess a fish community. There are several topics that cover and somewhat describe how to best do this. Keep in mind sampling the fish is not just catching them, but more importantly keeping records of all species, all their lengths and often the weights of larger sportfish. These data will then help you & your friends, with some nudging from us, to get the pond on a path toward better fishing.

Thanks for the info, guys! I'm looking forward to open water, and you can bet I'll be catching up on some reading around here between now and then.

Bill Cody, Thanks for the info about the pond I'm working on. You were right about the gills following those zooplankton regardless of depth. We are catching them just an inch or two below the ice in abundance.

From your experience and best guess (given the limited amount of data currently available), do you think balance can be restored or is draining and starting over usually the better path to take.

NE Chad - Presence of zooplankton and fish within a few feet of the ice can also be due to lack of oxygen in the deeper waters which will force practically all oxygen consuming, mobile organisms toward the surface. Main good way to see if DO is okay near bottom is to catch a fish there. Presence of feeding fish near bottom indicates DO is adequate at that depth.

I normally do not work on ponds as big as 5 ac. But if your problem is mainly too many small BG and too few bass then the problem should be comparatively "easy to fix". Desired speed of restoration and BUDGET will be factors in how to proceed. Relatively easy to fix assumes 1. there are not a lot of carp or bullheads, and 2. Crappies are not common or abundant. Those two problems make restoration much more difficult in comparison to a problem of just too many small BG.

IF the main problem is too many small BG do not try to fix the problem by just stocking fingerling bass - this will give very poor if any success. In this case one should remove lots of small BG and also stock bass that are roughly 3 times longer than the average size of small BG that are being removed. Depending on when in the year the lots of small BG are removed then sometimes one can also add fingerling bass with the larger bass. Explanations will come when the work gets started or I think the specific how to advice is located on the PB forum.

Those fish you are catching just below the ice are they true BG hybrids, green sunfish or a mixture ?.

I will look to see if I can find some info about fish sampling on the forum. If I get anything I will post it on your forum thread.

True BG is all I have seen.
I'm interested to learn more about the crappie population too. Haven't been able to catch any under the ice.

Nebraska Chad -- one more thing. Can you get this winter to end? We'd all be glad to have the ice gone!

Well it has been 5 days since I collected the samples and I'm not sure what conclusions I can draw. I will provide all the details since I'm not sure what is relevant.

- The jar has been stored in the cool, dark basement.
- The yellow tint to the water remains unchanged.
- The zooplankton seem to have multiplied.
- The zooplankton were initially contained to the bottom inch of water, but are now evenly distributed throughout the jar.
- "Stuff" has collected on the bottom of the jar, but I'm not sure if it's sediment settling out or dead zooplankton.

Extra zooplankton? That's cool. Sounds like of like your tinted water is all alive. Phytoplankton and zooplankton. I think you should get some alum from me and we'll add it and see what happens.

So, the little data currently available indicates healthy water. Well, I like that!

What about the plankton will give the water a yellow color?

My first taste of alum is free, huh? Are you trying to get me hooked?

Trust me Chad, once you get a tiny tinsy taste of alum, the after taste will be there for days.. I doubt you will be hooked.

Still searching for an answer on the yellow tint... why and what (if anything) should be done. Have spoken with a few experts, to no avail yet. Any guesses?

The guys on the bottom left appear to be the fellas swimming in my jar.

Are they Copepods (Cyclopoid)?

The type on the bottom left are Cyclopoids of which Copepoda is the class name. Most of what you now have in the jar are likely copepods. Without adequate suspended particulate food most of the filter feeding Daphnia types probably have died. Many of the copepods are predatory grasping feeders and will usually live longer in a jar than the Daphnia types. The current community in the jar could be quite a bit different than the one you originally collected.