water temp changes

[shizzy]

If and how do fish react to a quick change in water surface temp? I was out yesterday on Gervais and the water was at 80 to 80.1 degrees. I went out again today and I was seeing temps of 78.8 or slightly lower.

[hhguide]

I know in the spring we were fishing in some warm water and wind swtiched sucked the warm water right out of the area the temp dropped about 4 and a half degrees and the fish shut off. but that was earlier in the year.

[BobT]

I usually figure that the entire lake temperature isn't going to fluctuate very much. That's a lot of water to move the temperature too much, too fast.

The surface on the other can fluctuate a few degrees. I've seen it change just because the wind came up. Wind will draw heat out of the surface rather quickly sometimes but my guess is that you don't have to go very far below surface to find more stable temps.

Bob

[shizzy]

thats kind of what I was figuring, the Crappies were biting in the same spot just as good.

[Tom7227]

Just to spin this just a bit - does a fluctuation of sub-surface water occur often, and will it make a difference? I have sort of thought that knowing what the temp was on top 3 inches of water was not really that important - it's what it may be down closer to where the fish are, or where there may be a fairly signficiant change such as where a spring comes up or where two rivers meet. Of course you would have to wonder how you would find that change of temp. Can someone give some information abotu the issue with sub-surface temps?

[Scott M]

If and how do fish react to a quick change in water surface temp? I was out yesterday on Gervais and the water was at 80 to 80.1 degrees. I went out again today and I was seeing temps of 78.8 or slightly lower.

Surface temperatures really don't mean too much without a complete vertical profile (top to bottom temperature readout). Unless you invest in a temperature probe, you won't really know where the thermocline breaks. Temperature is important for some species (think of trout on the Great Lakes...also explains why many boat captains have temperature probes hooked up to their downriggers), but most important is oxygen. When there isn't a lot of wind, lakes sit still and stratify. Oxygen drops out below a certain depth. Fishing actually gets easier in a way because fish become concentrated to where there is an acceptable level of dissolved oxygen. When you have >3-4 days of hot, warm days, go shallow because oxygen can cut out. Each lake is different, but I have seen it cut out as shallow as 9 feet and as deep as 35 feet. If you get good wind mixing you can probably safely fish most of the depths of the lake.

I think surface water temperatures are more important in the spring or fall, when water temperatures are more uniform from top to bottom and water temps can be monitored until its your favorite species' time to spawn (e.g. crappies) or hit the feedbag (shallow fall muskie or bass).