Hard winter vs. Mild Winter on holdover trout

[PaulK]

My instinct is always a mild winter is easy on trout. But could this be counter-intuitive?

A hard winter freezes the creek over fast and then the snow covers the ice. Maybe the trout are in deep hybernation, and there are no predators (including guys winter fishing) Then the trout come out in the spring with big appetites. Let's say there were no devastating ice flows to harm them. Could hard winters be good one's?

A mild winter sees open water, maybe more predation when the trout are barely surviving. Possibly some anchor ice since the stream didn't ice over fast can make things more difficult. Possibly some winter fisherman hitting them with success in Feb and March. And the trout might be less motivated in the spring since living has been easier throughout the winter.

Anyone like to discuss? Or should I just get into my waders and fish already! hahaha!

 

[troutbert]

I think the number of hatchery trout that holdover through the winter is very low.

Think about the number of hatchery trout stocked in the entire state early in the year, say Jan through June.

What percentage of those trout do you think are still in the streams on opening day the following year?

 

[Cold]

I think the number of hatchery trout that holdover through the winter is very low.

Think about the number of hatchery trout stocked in the entire state early in the year, say Jan through June.

What percentage of those trout do you think are still in the streams on opening day the following year?

That doesn't address the question at all, though.

Anyone like to discuss?

Just shooting into the dark, but I'd say that in PA (with watersheds that do not depend on the snow pack to support flows) a mild winter is better for the trout. With a winter like we had this year, food was likely available to the fish throughout the entire winter, and temperatures were mild enough that they wouldn't have to do the whole"hibernation" thing too much. Sure, their body processes likely slowed down just like every winter, but I'd think that the milder the winter, the more insects (midges mostly, olives too) would be encouraged and able to hatch, which would result in more readily available food.

I wouldn't think that predation is a highly significant factor in holdover survival rates through the winter months.

 

[salmonoid]

I read a study (which I can't currently place my hands on) that demonstrated that the presence of ice had a beneficial effect for the reason you stated - it shielded the fish from predators of the above water type. This would be birds, coons, etc. and of course anglers.

But if it gets so bitter cold that anchor ice forms, that could negate the potential positive benefit of overhead ice.

I know from my own observation of trying to fish after the blizzard earlier this year that ice also changes the hydraulic nature of the stream, in that it forces the stream to flow in and over areas it would not when it is ice free.

Snow pack in PA has little effect on stream flows.

I believe Mike has stated that harsh winters are hard on YOY trout.

 

[pcray1231]

I think the number of hatchery trout that holdover through the winter is very low.

I tend to disagree. Though that depends how you define "low".

Just judging by special reg areas that are stocked in the fall, I still catch plenty of fish prior to the spring stocking. As many as right after they're stocked in the fall? No. But enough to make it worthwhile. If I had to put a number on it, I'd say my catch rates are probably over 30% of what they are in the fall. I don't want to say comparing catch rates is fully indicative of exactly what % are still swimming. But if you did use that, 30% stocky survival in 4 months over winter, I don't call that low by any means.

That's special regs, though, which is where most fall stockings take place. So harvest is taken out of the equation.

I think the % that survive SUMMER is much, much lower, and that's because the majority of stocked streams are stocked because they don't hold significant wild populations, and they don't hold significant wild populations because they get too warm for trout in the summertime. A few make it. More in some places than others (places that stay cooler, or else at least have easy access to cool tribs or spring holes). But overall it's pretty low.

Anyway, to answer the OP's question. I'm shooting from the hip, admittedly. A mild winter is probably better for trout survival on average. I'd imagine the key is probably ice flow. Which means, perhaps it's not whether the winter as a whole is warmer or cooler than average. Moreso, even in an overall warm winter, if you get that "polar vortex" for 2 weeks and form a lot of ice, and then a big rainstorm to blow it all out, the ice doesn't melt in place nice and slow. Rather, you get brown water with zero visibility with massive imbedded ice chunks flowing at high speeds. Not good. Directly kills fish by impact. Or, if nothing else, scours lots of sediment into the water which can suffocate fish.

On the other hand, it could be pretty dang cold all winter long, with some ice formation, but never really blow out. In the spring you get a slow, even melt from the top down. All is well.

So maybe you shouldn't think of it as mild vs. severe winter. But rather focus on "events" or lack there-of. The negative events are probably more likely in a harsh winter, but it's by no means universal.

 

[JackM]

Holdover rates through winters whether harsh or mild probably depend upon the health of the trout prior to sustained sub-40 temperatures. But all that being equal, I would bet mild winters are better, It seems like common sense.

 

[troutbert]

Cold wrote:

I think the number of hatchery trout that holdover through the winter is very low.

Think about the number of hatchery trout stocked in the entire state early in the year, say Jan through June.

What percentage of those trout do you think are still in the streams on opening day the following year?

That doesn't address the question at all, though.

True. So here goes:

Holdover rates are higher in mild winters than in severe winters.

Winter is what the fish are surviving. What is the hardship that winter presents? Cold.

So, the less severe cold weather in the winter, the higher the survival rate.

 

[724flyfishing]

I've caught some nice trout in the dead of winter in streams that don't support wild populations, that are only stocked in the spring. I think the summer has more of a impact than the winter. If they survive our summers, especially in a freestone stream, I'd be willing to bet there's a good chance they can handle whatever winter throws at them.

 

[Chaz]

Since I rarely fish stocked streams I probably shouldn't even offer an answer. But a hard winter often brings anchor ice, once this happens whole sections of a stream can freeze top to bottom. That's why making sure fish can move up and down in a watershed is so important. A fish isn't a holdover until it's been in the stream for a year from stocking.
Trout don't always adjust from being fed to foraging for their food either. This causes a lot of fall stocked fish to be too skinny going into winter. This happen after the spawn with wild trout, they don't always gain their weight back and die due to malnutrition. We see a lot of skinny fiwshpics posted over the winter and early spring.

 

[Reeder]

I fish Lycoming Creek all year long since I live so close. It always has a decent number of holdover stocked trout each year. This year was by far the best I have seen in the last 15 years for holdovers. We had a cool, rainy summer and a mild winter with less than a foot of snow all year. I think the cool summer played a bigger role than the mild winter, but there really is no way to tell.

I have never caught a skinny holdover out of there either. The trout I was catching from January-March were quite healthy. Some of them even had sagging guts on them from all the natural foraging they were doing.

 

[PaulK]

Thanks to everyone for their insight. Reeder painted such a great picture I may need to fish LC