Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Yearly SMB population explosions

Years ago as a younger man, I stocked my parents 1 acre pond with about 15 lunker Small mouth from other hidden ponds in the Sumpter Valley area. The pond was barren of fish and had the richest assortment of critters I had ever seen. In the second season after I added the fish, I walked down to go fishing and saw about 100 dead fish for every 10-15ft of bank. I would dangle my grub off the dock and have multiple small fish jump for it. In the third year I hooked into only 2 larger fish, one 2.5 lb, and a 3 lb SMB. Obviously the original stocked fish. Now, every year there is a population boom and a large fish kill. The pond has great habitat, deeper water, lots of overhanging brush and thick vegetation. Should I stark culling them? Is there a way to get the lunkers back without batting thousands of fish each year???? I haven't caught a fish over 1/2 lb for 7 years, but I could put 5 hooks all with a grub on them and reel in 5 fish at a time!

Ps. Years ago, I scared a mamma duck with a bunch of ducklings off the bank. They tried swimming across the middle of the pond, soon as they hit deeper water, small whirlpools started opening up sucking the baby ducks down. In 20 seconds, poor mamma duck only had one baby left.... Gawd I love bass!!

Welcome to Pond Boss, Jimbo!

It sounds like you have the classic problem many of us have with LMB ponds--stunted predators.

The experts can help you figure out why you have a yearly fish kill, but it sounds like problem #1 is a lot of jaws to feed and not much forage to go around.

When you say that the pond was "barren of fish and had the richest assortment of critters I had ever seen," what exactly do you mean? Was there any forage in the pond prior to stocking SMB [either baitfish of some sort or another reliable source]?

Just thinking out loud here, could the larger SMB be gorging themselves on YOY SMB and puking them up? When I pen raised my SMB I BG trained them, after feeding them 7-9 dozen small BG there would be a dozen or so BG that were regurgitated and floating in the pen the next day.

Maybe once the water temps got warmer in the spring the small number of big SMB are gorging on the smaller SMB? If the larger SMB are still there then the numerous small SMB would make them difficult to catch. Lot's of food, little competition. How big are the smaller numerous SMB, 4", 6", 8"? What sizes are you seeing when a fish kill occurs?

The other possibility is with too many small fish there simply may not be enough food to keep them healthy, if some sort of stressful event came along they would likely be the first to succumb to the stress.

There is a lot of stresses the fish endure. It freezes hard every winter and is only fed by groundwater during the later summer months (I think), because the creek feeding it dries up.

By critters I mean leeches, frogs, snakes, and a disgusting amount of free swimming shrimp, (about an inch long when mature) and all kinds of other tasty morsels for a bass. The bottom of the pond is almost entirely covered with vegetation too.

The pond had no fish whatsoever when I started. And now it only has SMB. The mass kills involve fish about 6-8 inches in length, I havn't seen anything bigger. The other thing that boggles me is there always seems to be an abundance of forage. And even the small ones are little porkers.

One side of the pond is covered with a giant pile of cobblestones, I've been thinking of introducing some crayfish.

Im with you, I think there is just too much competition, is there a way to slow spawning?

Adding BG to the mix would slow spawning, they will eat the eggs off the nest and you would likely get NO recruitment of SMB in the long run. A better bet would be to seine excess young of the year out periodically, concentrate on the 6-8" size, consider the smaller ones as food for the bigger SMB.

What time of year is the fish kill occuring? Winter time? How deep is the pond? This might help us understand the possible causes.

The deepest part of the pond is about 15 feet by the dam and it steadily shallows to the far side of the pond. I bet the Bluegill would thrive in the shallower end because a layer of vegetation sits on top of the water providing good cover. The fish kill happens in July-August, when the water level is at the lowest. The lowest water level I have ever seen was about 2 feet below the spillway. Will stunted fish grow bigger once the problem area is corrected, or does it take another generation?

If there aren't any BG in your pond now, I wouldn't add them. BG and SMB don't mix well. SMB don't tend to keep BG numbers down. I would first thin out the small bass in your pond. Remove many of the of less than 10" bass you have right now... You can then look into a source for golden shiners. Purchase the largest you can afford and in the most numbers and add them to your pond.

Great advice so far. I'm intrigued by the 6-8" SMB fish kills if indeed they are fat and getting enough to eat. A diluted oxygen (DO) crash in the summer, perhaps? My first guess would have been that they were too skinny and no getting enough nutrition, but that seems like it is not the case.

To answer the quoted question above--Yes, the stunted fish will grow larger once the problem is corrected. More food and less competition = longer and fatter SMB. However, the stunted ones cannot compensate for the lost time. They'll get larger, but they'll be behind the curve for their age. The yoy, if they get enough forage, have the potential to get larger than the stunted parents.

how about a smb/gsf pond?

Jimbo, if the fish kills are happening yearly, I'd worry about how to fix that issue before worrying about forage. Believe it or not a SMB only pond can do fine by itself and if there are other critters they'd do okay. (I know Dr. Dave Willis can speak to this more as he's written about it)

The fish kill is the issue. Fish just don't die every year en mass. (well, they're not supposed to anyway) Especially if it's happening yearly. You mention no fish over 1/2 pound in 7 years. Was it about 10 years ago that you put the smallies in? Have you had a fish kill every year? What time of year? (always july-aug?_ I'm assuming no aeration? (can you run an aerator to the pond?) Is there lots of vegetation? Do you know what color the water is when the fish die? Other times of the year? If it's low DO and you fish kill every year adding other species will only complicate the problem.

I would bet it is a summertime DO sag caused by an algae die off that happens very quickly . Does this die off happen right after a stretch of very hot sunny weather that is then followed by a strong cold front with clouds and rain for several days?

Wouldn't low O2 levels affect the largest SMB before the small ones, as with most other species?

Yes it would... That is why this scenario makes no sense to me?

Very true Theo, he did say that he hasn't seen a SMB over a half a pound in last 7 years. There might be a reason for that, maybe just the months old fingerlings are the only thing surviving after each fish kill.

Do you think the ammonia levels are skewed? You said you saw 100 dead fish for every 10-15 feet. If you have a ton of fish without a new source of water can't the water chemistry get messed up and lead to a nitrate or ammonia spike? I know this applies to the home aquarium but wonder if it would apply to a pond. This usually targets the smaller fish as the larger fish can live thru it. Just an idea I could be wrong of course.

RB, I don't have much experience in that area, but I recall reading that what you described can and does happen with ponds.

You might be on to something with that idea. The problem could even be a combination of ammonia buildup and DO crash--both from too many fish using up the O2 and creating waste product.

It certainly sounds like a water quality issue to me. It appears that your fish kill happens when the creek stops providing fresh water. Is that true?

Hey, Sorry for the wait. I had one hell of a week. I got stranded in Northern Washington with my bicycle and had to go 45 miles to get to a bus station. I left half of my stuff up there with a buddy (computer Included) and hopped on my bike. So the Canadian border patrol wont let you into the country if you have a DUI less than 10 years old!?!? I was SUPPOSE to be presenting a paper that I got published at a scientific meeting. Anyway, I really appreciate the help you guys provided, Im heading to my bass pond in the next couple weeks, I'm going to introduce some crayfish, run some water quality tests and devise some sort of aerator. I cant get power to the pond, any ideas about how to aerate?

Yeah it was the Canadian border patrol that wouldn't let you through EH? How about the guy that drives drunk in the first place?? Sorry to hear about the hassles though, border patrols of ANY nationality can be a royal pain

Gotta love border patrol. They almost pulled me and my vehicle to the side because I have military decals on the windshield. I guess they thought I was starting an invasion.

The Canadians are very serious at the border if you have a DUI on your record. You need to bring proof of your atonement such as proof that you did community service and took an ARD course, etc. etc...

My company has an office in Canada, and we send people back and forth from the USA to Canada and reverse.

At the end of the day, any border agent can deny you access at their own discretion.

If they don't like your attitude, they just deny you access.

So what's the answer....have all of your paperwork and be very, very nice.

Only been to Canada once, beautiful country... It's their right like any other country's to deny anyone for any reason. I could go getting all political but I won't.

Robert Heinlein once wrote that Canada was the part of America where the people were so smart, they never paid any taxes to Washington.