Pond Boss Forums INTRO Questions & Observations Trout question

I noticed yesterday that my Rainbow trout were opening and closing their mouths while swimming. It almost looked like they were gasping, but none were on the surface and were very active, feeding and swimming. This is the first year stocking after excavation last fall and filling this spring from snow melt. I have not measured d.o. yet but have monitered temps occasionally. There is no obvious problems that I have seen, and up until about a week ago the water has not even been clear enough to see the fish. Is this reason for concern or normal behavior? It was very hot the last couple of days with daytime air temps around 90f.

What is your water temp? They still could be short of D.O. as water temps rise and can not hold as much oxygen, and/or they have rapid metabolism due to warmer temps. If your water is over 70 they are stressed. I once had a pond that got too warm. The trout rapidly swam around the shoreline over and over until they died.

You could have some environmental gill problems too if the reason your water was not clear was due to sediments or other irritants.

What you are seeing is not normal unless they are filtering zooplankton.

Cecil, the last temp tests were done before the hotter weather. Surface was 69f, 3 feet 67f, 6 feet 64f, 8feet 56f, and bottom (13 feet) 50f. At 6:00 am this morning the Trout were feeding heavily on surface devouring a caddis hatch, everything "seems" normal. I finally did an actual pond measurement, it is 170ft x 45 ft x 15 foot deep (when full). Stocked in May with 150 6" Rainbows. I have purchased an air compressor which I am planning on installing soon, but was only going to aerate during winter months. I am having a hard time finding a reasonable priced, decent quality d.o. meter, best so far was $800 CDN. It would certainly take the guess work out of it. Thanks for your reply Cecil.
Wood

Last year I was offered an unbeatable deal, 6 Lb Rainbows @ about $6 each. I couldn't resist the experiment and bought 45. The action was incredible until my pond hit 70 degrees F. Inside of a week all were dead. The only possible positive note was that a local Osprey retrieved many of the dead for its' nestlings. Rainbows are just not made for warmer temps.
Jim

Wood-what you are seeing is not normal as Cecil has described. You have limited time to get aeration in the pond or you will really be in trouble. My pond is similar to yours and i had a 90% fish kill last year with similar temps. My trout did the same thing and slowly died. Yes some will live but not many. I even had a bottom diffuser and that wasn't enough and had to purchase a top water splasher. My temps are now like yours and i have the same number of trout. If you can you need to get something set up even if you have to hire some kids to run arround it in a paddle boat to splash the water. I wouldn't worry about buying a D.O. kit until i get the aeration system going. Kasco makes a great top water splasher. Also running the system is fine in the winter but only serves the purpose of keeping a spot open so sun can penetrate. July and August will be critical for you this first year, run the aerator at night and on clowdy days and just work on getting through the summer. Again, i would get a top water splasher now!! Trout don't do what you described.

jd

The heat wave is over, was 90 again yesterday. A strom blew in with large hail. By 6:00 last night air temps were 64f. Pond temps as follows:
June/20 before heat wave:
surface-72
3ft-67
6ft-64
8ft-56
13ft-50
June/30
surface-72
3ft-69
6ft-68
8ft-56
13ft-56
That is as hot as it gets in my area, I will put in the aerator, what depth would you suggest. There has also been another TERN of events. I noticed yesterday morn. a tern circling and checking things out, I came home last night and saw one flying away with a trout. Any suggestions on a deterent, although after reading these replies, it may not matter. Needless to say, I am not impressed, but I was warned by many of you more experienced guys that this may happen.
Thanks again, Wood.

Wood,

What you probably have is a situation where even though you have cooler water the deeper you go, your D.O. level is dropping too as you go deeper. So your trout are going to the surface during a heat wave, but the temps are a little warm for them there but it's a catch 22.

JD is right. You need some type of surface aerator if your trout are worth keeping. Additionally It's kind of silly to shoot your wad on a D.O. meter to find out you D.O. is low (sounds obvious to me) but you don't have any more money to do anything about it.

I do believe you can get a surface aerator for half of what the D.O. meter would cost. AES sales a Sweetwater surface aerator that pumps 120 gpms for $485.00. In winter I would use the compressor/diffuser type as I do. I use the compressor/diffuser in summer in my trout pond too, but I have 38 to 45 gpms of 51.6 well water running in 24/7 that keeps things cool. But I also shut it down during the day when air temps reach 80 F. I have enough of an algae bloom to produce enough oxygen during a hot sunny day anyway. I turn it back on in the evening when temps and the sun drops.

It's not as simple as if conditions are not right they will just die. If conditions are borderline or fine during cool weather and back to bad during a heat wave your fish will probably come down with disease from the stress. That's not a pretty sight either.

Wood-I have nothing more to offer. Cecil said it just as i would. Surface during the heat of summer to get high D O, and a simple diffuser in the winter set off to the shallower area. This shallow area will not mix the warmer comfort zone for trout in the winter. Best of Luck. Hey Cecil did your internet expert get back yet? If you would like i can send a self addressed stamped envelope with some cash to pay for the pictures of your aereated well water set up.

Have a great 4th fellas.

JD

Cecil-i re-read your response, correct me if i'm wrong but you have aerated well water running in 24/7. That is a huge difference than what i do just runnning well water in. If i did what you do i probbly could shut my splasher off, am i correct?

just checkin-jd

Thanks for your input guys, I have set up the air compressor with weighted soaker hose and I guess time will tell, can't hurt to try at this point. My aquaculture permit limits me to only a few species, Brown, Brook, Rainbow & Tiger Trout as well as Artic Char, thats it. Would any of these fair better in my climate in your opinion?. Also, as far as the Terns, my wife bought me a plastic owl which I mounted on a pole by the pond and it does work in a round about way, it seems the hawks really don't like him and have taken to dive bombing and smacking him with their talons sending him spinning on the pole. Have not seen a Tern since.
Wood

The air compressor with weighted hose may make things worse, but if you are not willing go with a surface aerator then you have nothing to lose.

You could be bringing up anoxic water. In fact, even in warmwater pond folks have set up a diffuser late in the summmer when a thermocline is well established and once they bring up that anoxic water they have a fish kill.

As far as what species would be better. Arctic char are out if you temps are marginal. Brooks too and browns would probably be your hardiest but browns and rainbows are pretty close.
Tigers are probably intermediate between brooks and browns as they are a cross of a brook and brown trout.

Bottom line is warmer water holds less oxygen and your deep cooler water probably loses oxygen as summer goes on. That is why you fish were coming to the surface. My trout stay deep most of the day unless it is feeding time which is early morning and late evening.

If you do not have a cool aerated water source like mine your best bet would be a surface aerator run at night.

Cecil, I would run a surface splasher, but power is 250 feet away, well water is not an option either. I was aware of possible problems going into it,but a guy has to try anyway. I do not regret building the pond as I will always have the habitat and the wildlife that it brings.
Thanks again, Wood

A couple of weeks has gone by since the heat wave and water temps have not exceeded 64f in any depths, I have not seen any dead fish, which does not mean I didn't lose some but activity has returned to normal and the worst is now over. I am planning on different tactics for next year to hopefully keep ahead of this. Thanks again to Cecil & jd for their common sense, informative advice. Wood