Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Rainbow Trout Survival in an Illinois Pond

Hi everyone,

My first time on the forum - I have a pond in Central IL that has been established for about 40 years. To try something new, we stocked 100 12" rainbow trout last October. We have taken about 10 out to eat, but would like to see them grow bigger, but we are afraid they won't survive the summer after we get a few 100 degree days.

The pond is just over 1 acre and is mostly over 10 feet deep with maximum depths slightly over 20 feet last we measured. The deep average depth resulted from dredging it about 15 years back, and we also increased the height of the dam about 10 feet, and raised the overflow. We aerate 24/7, and just resumed feeding twice a day this week.

Historically our stocking has been fairly typical for the area - Largemouth, Bluegill, Channel Cat, Redear Sunfish, Black Crappie, and two HUGE grass carp. We selectively harvest every year and have had great success - decent amount of 5 lb largemouth, plenty of crappie over 1 lb, and numerous catfish over 10 lb. Bluegill are very populated, and mostly mid-sized. Right now we definitely feel like we have too many fish and plan to take as many out as we can this spring (especially 1-2 lb bass).

That's basically it I think. So far we don't have any plan other than harvesting fish and feeding the ones that stay. It would be great if say 50 or so of the rainbows survived the summer, and if that happens we may continue stocking them in the future. If not we probably won't.

Any thoughts? These are the ideas I've had:

1. Aeration Control - Cycling the aerator when the outside air wet bulb temperature is below 70°F seems like it would be ideal, as this is the temperature that surface water will approach.

Probably more simple would be to only aerate at night, with a timer, which we already have setup for use if we want.

The concern is that the circulation of water caused by the aeration system will result in deep water temperatures exceeding 70°F, where everything I read says the trout might start dying. If we don't aerate though, they might die from lack of oxygen!

2. Floating Islands - Seems like a lot of work and probably money. The added shade could only help, but I just don't think we have the resources.

3. Make the Pond Deeper - Less work than the islands, but we've seen off and on wet spots on the back of the dam over the years, and we're terrified of what it would look like if it collapsed. I think we are far from that, but we'd really like to add more dirt to the dam first.

That's all I've got - anyone have any better ideas? Any input would be greatly appreciated.

Thanks!

Welcome K.P. to PBF,

I am not a pro and one will be along to offer advice I am sure. IMHO, you already have your experiment in progress. I would harvest a few more and see what happens. I do not expect a good outcome but that raises your chances of success as I am mostly wrong!

Good luck and again welcome!

Bill D.

I'm sorry to say but trout are trout and require cool, well oxygenated water... Given the size of your pond, you just don't have the volume to keep water temps low enough but dissolved oxygen levels high enough. Enjoy the put and grow fishery. Stocking fall trout is a blast.

I agree with CJBS above. Trout are trout.

They need lots of oxygen. As the water warms, it progressively holds less dissolved oxygen. By the time it gets to the upper 60s F., it can no longer sustain the oxygen needed for trout.

However, I believe your are probably in about the same temperate zone as me, and where CJBS hides his trout at their Pennsylvania cabin.

Yours probably won't live through the summer any better than ours do.

As CJ said, they are a blast to stock in the fall. We love them. Their acrobatics when we feed pellets are incredible. They are also pretty good when smoked and turned into smoked fish spread.

I stock ours around the middle of October, about the time the water drops below about 65 F degrees. My goal is always to get mine out by May 31st. It never happens 100%.

I usually stock mostly golden trout, which are rainbow mutants, and readily available in this area. The can easily be seen in the water. Those that I can't catch by the end of May usually seem to live at least through mid-June, sometimes into early July.

Good Luck,
Ken

Best to only stock as many as you plan on harvesting, maybe a few more. Bigger largemouth bass love them some trout too.

Trout survive in Central IL in non-aerated BOW's....Beaver Dam State Park has them in it and it's not aerated nor terribly deep (max 10-12 feet). It's also not ridiculously large (their website shows it as 60 acres, I'd say it's closer to 50), but I guess it's just large enough?

I tried the same thing last year in our 1 acre pond that's 12' deep here in northern WV. Last week during sustained high temps. I found 2 rainbow carcus that the catfish had devoured.

They did great from sept until about may, doubling or tripling in size but the heat got them in the end.

I am in Hillsdale County South Central Michigan. I have .10 acre pond with max depth 14'. The pond average would probably be considered only 6 to 8 feet. I have had trout make it through two summers now. I have been lucky. I did lose my very largest trout, just over 30" Golden Rainbows and perhaps 4 more large Rainbows over 20". The other 64 trout made through though.

Here's what I have done;

In the summer I lose about .25" to .30" of water a day. I let my pond lose this water and watch the weather forecast, I always have 2' of water I can put in the pond for that "heat wave". I run my aerator 24/7 in the deep end and I run a 90 gpm fountain 24/7 when I see the heat coming. As soon as the heat is about to hit, I run the water to the pond at about 15 gpm and let it get that 2' it needs and start to overflow into the drain.

This said, I have been lucky, it really hasn't been terribly hot the last two summers. I'm trying to hedge my bets and put a well in next to the pond so I have 30 gpm to run full time when the heat is about to hit.

Oh, one more thing, I feed them NOTHING as soon as the heat even starts to threaten kicking in. My water got to 74 degrees last year and my trout were not fed when the water got to 68.

Are you going to harvest the biggest ones this year to prevent loss?

If I can catch them

"If I can catch them." There have been a lot of books and magazine articles about that.

That is a trick for sure, especially if they are dormant now. I know there were at least 20 trout left in our pond this march. Some in the 6lb range. We have tried everything to get them excluding electroshock.

I have a situation similar to timshufflin. My pond is dug into the water table in a steep, narrow valley about 25 ft. from a stream that runs year round. The stream is about 15 ft. wide and remains cold enough to hold trout year round. My pond is about 1/3 acre in size with a max depth of about 7 ft., with 3 ft. being the average. It is about 3/4 shaded even during mid-day. The water level can drop up to about 2 ft. in summer, but never gets any lower and always refills with a few good rains. I have two sources that feed the pond and avg. 2gpm and 5gpm, but they only run from Oct.-July regularly. Groundwater temp is 54F. There is no regular above ground water source feeding the pond during Aug. and Sept. The trout(browns and rainbows stocked spring 2013) do fine all summer despite this. I assume these sources still flow underground into the pond during these dry periods since they are literally coming off a 70 degree slope. Using a temp. logger last summer I recorded my highest surface temps at 70F on three or four days during Aug. The bottom is consistently 4-5 deg. cooler. I use a bottom diffuser from June-Oct. during the time period of 3-8 AM, when the DO is lowest. I assume since the pond is a few feet higher in elevation than the stream, that it is intercepting any spring water attempting to make its way to the stream. Any thoughts on this anomaly?