Water death temperature question for trout.

[HoundsNTrout]

What is the range that will likely kill small 4 inch rainbow trout and brook trout in say a 4 feet deep pond with good inflow and outflow. ? A pool of sorts 8000 gallons or so. 4 feet around edges and 6 feet on bottom in an area maybe 15X15. That's it.
In small pond with ice-over most of the winter from January through March.
Anyone with experience. Not googling. lol
They were being fed up til Mid January, then stopped when water hit 40 degree surface, never came back up or hiding on bottom or died? I can't tell yet still frozen over. But water flow in is still going on and snow melt.
ITs 36 to 38 degree surface right now.

 

[Tomt37]

Can't remember the temp but I had some I got from a reservoir breeder years and years ago and they needed massive oxygenation and any increase in temp is gonna lower the oxygen ... I only had luck with them when tank was out on garage ... in shade ...always really cool with .. like 8 or 9 Celsius and tons of air stones in

 

[Tomt37]

Doh should have read all your post ... they didn't last in my pond ... I think they can't slow down oxygen requirements enough in winter and usually live in fast flowing water that doesn't totally freeze

 

[Chub_by]

If there is still water flow in the pond they might just be hiding, however trout don't have a real phase of low activity like many other fish, are you feeding?

 

[Tomt37]

as long as theirs good flow there should be complete freezing .. otherwise I'd break it up and feeding could def be reduced significantly or stopped for a while

 

[HoundsNTrout]

If there is still water flow in the pond they might just be hiding, however trout don't have a real phase of low activity like many other fish, are you feeding?

First of all I know a lot about FISHING for trout. lol. Just still learning about the raising and all aspects of certain things such as low and high temp's. DO content of water was 7 at the low and 9 right now ( because of cold snow melt coming in ). Ph of 7. very small stream constantly running through my raceway and into the hole then out at same rate.

I WAS feeding as long as I saw at least some coming up for the food. THen all activity stopped when I had stopped for 2 weeks. However, this coincided with a big cold spell. 10 degrees for 2 weeks. Frozen over. This would have been from end of January til right now. I just started feeding at the hole I made but so far nothing. SURFACE temp's are still 36 to 40 in spots.

4 inch fish that WERE eating from that pond until first ice-over and even after for a few weeks, should have made it through the winter. But who knows. ALL other things add up ( ice cover helping to keep the warmth at the soil , flow in and flow out, good dissolved oxygen and good temp's UNTIL now LOL )

I mean I rarely see any trout in the stream either til water hits 42 to 45, then once surface hits 48 to 50 trout suddenly appear. LOL
Hoping that's the case here, but what IF the temps near the bottom or near the sides were 34 to 36. Would that kill them ?
They were fairly well fed in the months prior to this so hoping the young ones could deal with it.

 

[fatboy8]

First of all I know a lot about FISHING for trout. lol. Just still learning about the raising and all aspects of certain things such as low and high temp's. DO content of water was 7 at the low and 9 right now ( because of cold snow melt coming in ). Ph of 7. very small stream constantly running through my raceway and into the hole then out at same rate.

I WAS feeding as long as I saw at least some coming up for the food. THen all activity stopped when I had stopped for 2 weeks. However, this coincided with a big cold spell. 10 degrees for 2 weeks. Frozen over. This would have been from end of January til right now. I just started feeding at the hole I made but so far nothing. SURFACE temp's are still 36 to 40 in spots.

4 inch fish that WERE eating from that pond until first ice-over and even after for a few weeks, should have made it through the winter. But who knows. ALL other things add up ( ice cover helping to keep the warmth at the soil , flow in and flow out, good dissolved oxygen and good temp's UNTIL now LOL )

I mean I rarely see any trout in the stream either til water hits 42 to 45, then once surface hits 48 to 50 trout suddenly appear. LOL
Hoping that's the case here, but what IF the temps near the bottom or near the sides were 34 to 36. Would that kill them ?
They were fairly well fed in the months prior to this so hoping the young ones could deal with it.

Think about what your're saying for a minute here. You say that you know a lot about fishing for trout so you'd realize in colder months trout do not feed on the surface. Why do you think fly fisherman change from summer and fall dry flies to nymphs? As for temperature you need to realize as well the deepest part of your pond is going to hold the warmest water. If surface temp is 36 degrees I'd be willing to bet that the bottom would be a few degrees warmer. Even your temperature concerns I'm confused about trout are cold water fish. The colder the better with them especially with brookies who have a sensitive high temperature range. I've caught plenty of both in frozen lakes and streams that bottom temps were in the same range. Is there a chance they swam away in your outflow? My advice would be to run a net through and see if you catch any.

 

[HoundsNTrout]

Possibly the outflow yes. ITs odd. Bottom is now 50 ish, top 52. One lonely trout in there.
If they hit the outflow or decided to all go out there they would have hit ground no stream, hardly any water.
No signs of mink. Like I said, I was feeding them and they were eating until late January. SO I assumed they were all hanging out in the area they liked, too shallow for anysort of thermocline I think.
Bottom and in the mud/leaves would have been the warmest. If I don't see any soon I'm gonna dig it deeper and a bit larger. THe outflow pvc is 2 inches but the mesh they POSSIBLY could have gone through but doubtful.

 

[Tomt37]

Last of oxygen and too much heat are the killers .. also if a pond freezes over completely with no current - they have huge oxygen demands and usually live in highly oxygenated water

 

[HoundsNTrout]

Last of oxygen and too much heat are the killers .. also if a pond freezes over completely with no current - they have huge oxygen demands and usually live in highly oxygenated water

Yup. Pond had good flow, even with freez-over. Outet was minimal. I fear they seeked out more oxygen or warmer area and simply died in the muck, but trout don't do well in muck.
So this one has me stumped. Or as they say skunked.
Its probably too shallow, all fish were 3 to 4 inches long.
The thing that is getting me is WHERE did they go? LOL. I mean not knowing is fine, but I should see a carcass. ANY carcass. So far just one fish alive. IF they managed to get out the outlet or underneath the dam ( dam doesn't leak that i know of ) I'd see the fish. Also same goes for upstream where the most oxygen would have been definitely in early winter and right now they is nowhere to really go up stream, all just swamp ish water, no pond no stream.
THat's why I built a dam so all that water comes down into the raceway drops a foot then all into the pond 30 feet downstream.
Very very odd why I see no dead fish or just one live one. MAYBE I'll get lucky and they ARE in the muck, leaves and will come out once it hits 60F which is what it was they were raised in those temps.
IDK.