What makes stockies move?

jifigz

jifigz

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Miff-Co, PA
Okay, this thread IS about stocked trout. I admit, stocked trout are something I don't much care about but I do fish streams that have them from time to time. Yesterday evening I fished a delayed harvest stretch of a stream, actually a stretch of water that I have never fished, and I caught one stockie. This stream also has wild trout and I spooked at least two of them in the hour and a half of time I had on the water. I caught no wild fish yesterday, however, and the only stockie I caught was from a beautiful pool that I came to where I could see like 15 fish milling around. Other beautiful areas that should hold fish I caught nothing and I saw nothing. I know I fished over plenty of wild trout yesterday, but I have been struggling to some degree. Now I am no rookie fisherman and I realize that trout, even stockies, can very much blend in just because you don't see them doesn't mean they weren't there. However, I actually feel that they weren't there and they hadn't yet really spread out from their stocking location. I think the fish were not all that spread out by those that did the stocking. The stream was stocked about 17 days ago at this point and I bet that all of those trout in that pool that I saw were literally dumped right into it. The stockie I caught was from that pool and it ate a bugger on the first drift through, the other stockies didn't look at it at all on the following drifts.

I tried dries, nymphs, streamers, nothing worked. I was more or less focusing on wild trout, but I didn't mind catching a stocker, either.

So, what drives the stockies to move? Time in the creek? A high water event? The upcoming warming waters of spring that gives them more energy? This particular stream was a smaller mountain freestone stream. And yes, I am aware they did a telemetry study on stocked fish in the past that I can also check out and I will.
 

The third page will provide the most pertinent info to your question, but will still not provide the perfect answer. It’s a very interesting article, however, and from personal experience I can tell you that it was VERY interesting to conduct the few years of follow-up work precipitated by AFM Rob Wnuk’s study. The executive summary in the linked report below expands on page 3 comments in the general article above.

A real head scratcher is that we first saw this problem in SE Pa limestoners. Donegal Ck, Lancaster Co started all of it, but in that stream it appeared that a lot of the problem was preseason heron predation. Moselem Ck, Berks Co, another limestoner, was another early problem stream. The point I’m making is that cold temps at the time of stocking would not have been the problem on those two.

I would add two other things. First, when we stocked the N Br Muddy Ck, York Co, the stream was bank full and overflowing its banks at two other locations. Despite this, residency was excellent with over 90 percent of the trout remaining within the 300 m surrounding the stocking points. Second, on all of the many streams that I surveyed, hardly any stocked trout moved upstream from their stocking points. The protocol followed was to electrofish 200 m downstream from the stocking points and 100 m upstream. There were typically only 5-10 fish in the upstream 100 m and those usually occurred in the first 30-60 m upstream from the stocking points. This would counter those who might expect mass upstream migration into wild trout sections given the sometimes large numbers of fish stocked during the early spring when the study was conducted.
Here is the report of the statewide study that followed Rob Wnuk’s study.

Obviously, given the second report, we biologists found this to be an interesting and challenging topic and I hope readers here will enjoy the topic as well.
 
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Wow, Moselem Creek Mike...that brings back memories.
 
Mike said:

The third page will provide the most pertinent info to your question, but will still not provide the perfect answer. It’s a very interesting article, however, and from personal experience I can tell you that it was VERY interesting to conduct the few years of follow-up work precipitated by AFM Rob Wnuk’s study. The executive summary in the linked report below expands on page 3 comments in the general article above.

A real head scratcher is that we first saw this problem in SE Pa limestoners. Donegal Ck, Lancaster Co started all of it, but in that stream it appeared that a lot of the problem was preseason heron predation. Moselem Ck, Berks Co, another limestoner, was another early problem stream. The point I’m making is that cold temps at the time of stocking would not have been the problem on those two.

I would add two other things. First, when we stocked the N Br Muddy Ck, York Co, the stream was bank full and overflowing its banks at two other locations. Despite this, residency was excellent with over 90 percent of the trout remaining within the 300 m surrounding the stocking points. Second, on all of the many streams that I surveyed, hardly any stocked trout moved upstream from their stocking points. The protocol followed was to electrofish 200 m downstream from the stocking points and 100 m upstream. There were typically only 5-10 fish in the upstream 100 m and those usually occurred in the first 30-60 m upstream from the stocking points. This would counter those who might expect mass upstream migration into wild trout sections given the sometimes large numbers of fish stocked during the early spring when the study was conducted.
Here is the report of the statewide study that followed Rob Wnuk’s study.

Obviously, given the second report, we biologists found this to be an interesting and challenging topic and I hope readers here will enjoy the topic as well.
Click to expand...
I read the first PDF that you linked and, you're right, it didn't answer anything but it was very interesting. Especially since I noted that this mountain freestone stream I felt like the trout didn't move at all yet in the section I fished and they are rainbows that have been in there for 2 weeks+. Rainbows showed the greatest propensity to wander it seems.
 
jifigz said:
I read the first PDF that you linked and, you're right, it didn't answer anything but it was very interesting. Especially since I noted that this mountain freestone stream I felt like the trout didn't move at all yet in the section I fished and they are rainbows that have been in there for 2 weeks+. Rainbows showed the greatest propensity to wander it seems.
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That’s part of the interesting thing in the expanded statewide study. Rainbows were LEAST likely to move. (Excuse the caps; they were not aimed at you, but emphasize that their movement was the exact opposite of what most anglers think). In fact their residency was significantly better than BT and ST. RT avg residency was around 90%. BT residency was around 55% and ST residency was around 50%. There was not significant difference between BT and ST residency. I don’t think you can get the exact figures from the report because we continued the study for a few years after the 2006 report and I the numbers I provided above came from all of the work combined.
 
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Interesting. In the stocked streams around me that I fish often I can find rainbows all year. They persist. So yeah, I know that rainbows stay put to some degree and that correlates with my real life angling experiences. These streams around me are all wild trout streams, too, so conditions are favorable for trout survival and they don't warm to lethal temperatures in summer.

One stream that is unstocked near me but has a stocked tributary I have found those rainbows many miles from where they were stocked, however.
 
jifigz said:
Interesting. In the stocked streams around me that I fish often I can find rainbows all year. They persist. So yeah, I know that rainbows stay put to some degree and that correlates with my real life angling experiences. These streams around me are all wild trout streams, too, so conditions are favorable for trout survival and they don't warm to lethal temperatures in summer.

One stream that is unstocked near me but has a stocked tributary I have found those rainbows many miles from where they were stocked, however.
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I have found (electrofishing) stocked trout in strictly wild trout sections upstream from stocked trout sections in summer on somewhat rare occasions, but the numbers have almost always been quite low when found. The exception was a site immediately upstream from the upstream stocking limit on the Ltl Schuylkill, which is also the downstream stocking limit on Locust Ck. It would have definitely been worthwhile fishing that 300-400 m stretch. The summer numbers of stocked fish were not extreme, but were reasonable. At the time there were few wild trout due to early recovery stages from mine acid drainage. It is still recovering and the wild trout numbers are better now (mixed species) . Farther upstream it is still better to fish one side of the stream rather than the other due to water chemistry.
 
Yep I remember. Used to do well there for them. There were some impressive/surprising amount of wild trout around that county when I was a kid.
 
I remember catching a lot of brook trout in Cocalico Creek after Trout Run (Indian Run) was stocked.
 
Unfortunatly I feel this study has caused a few issues. I grew up fishing French Creek in Chester County. Seems that the current conservation officers (Chester County) have determined that since some trout, not all, may move either upsteram or downstream, they have elimnated stocking trout no closer than 1500 yards from posted or non-stocked portions of the stream thus eliminating numerous previously stocked points. This has now reduced the stocked portions of the stream considerably. When I spoke to the current WCO, he stated that this decision was made by the upper level PFBC leadership. I suppose my question would be that since 80/90% of the trout stocked in Frech Creek are Rainbow Trout and Mike has stated that rainbows are probably the least likely trout to move, why worry about a few fish that may end up in the "Fishing Not Allowed" section of the stream. Maybe the PFBC should review this policy on a stream to stream level and then decide if it is not be better to provide anglers more fishable water, with a few fish being unable to be caught, then to condense the fishable sections of a particular stream so that anglers have fewer miles of water to fish.
 
I've always kind of debated whether "residency" is a good or bad thing. Most of the streams I know, largely in part due to road access, have stocking points a mile or two apart. And it's a very, very bad thing when there's a load of fish at the stocking point and not much in between. Concentrated fish = concentrated anglers, and it's a bad thing. You want people to have an uncrowded, realistic fishing experience, instead of learning that trout fishing means rubbing elbows trying to move in on the bucket hole.

On the other hand, high mobility means fish are more likely to invade wild trout water, which is bad.

I certainly don't have any major insight into what causes trout to move. I know a couple of highly acidic streams that trout leave in short order, and that situation is quite obvious. But other than that, I've observed trout staying put one year and leaving the next in the very same stream. Flow likely plays a factor.

A question. It was mentioned that the temperature hypothesis was tested. The idea that trout in warmer hatcheries may seek warmer water, and vice versa. And rejected. But when it comes to water chemistry, it was just basic and acidic, not normalized for what they came from. If steelhead and salmon are any indication, trout are exceptional at determining water chemistry, and have a tendency to seek out the water where they went through some stage of their development. So it could make sense that a trout raised in limestone water would stay put better in limestone water, and a trout raised in freestone water may stay put in freestone water. Just a thought. And water chem goes far beyond pH as well. I could very easily see a trout stocked downstream of it's hatchery, can smell it's hatchery.
 
If you put on your chest waders, wade as deep into the pool as possible, and thrash around with your wading staff, those trout might move.

The best time to do this is on opening day at 7:50 am.
 
troutbert said:
If you put on your chest waders, wade as deep into the pool as possible, and thrash around with your wading staff, those trout might move.

The best time to do this is on opening day at 7:50 am.
Click to expand...
Yes, if you want to get killed. :D
 
A couple of unscientific observations that probably mean nothing...

I fished Section 1 of Dyberry Creek once with the memories of a 1982 PA Angler article in my mind. I started in a beautiful part of the creek just above Section 2 the FFO water and I couldn't buy a fish while my two buddies were killing them about a mile upstream, I assume where they dumped the fish...​
​
I hate that creek...​
​
A few years ago I fished Section 2 of the West Branch of Chester Creek, a childhood favorite of mine. The only place I could catch anything was in a hole right next to Valleybrook Road...​
​
I have too many fond memories that creek to ever hate it... :)​
​
I fish Section 2 of French Creek in Chesco a couple of times a season because it's where I caught my first trout so it's extra special to me. It does see it share of crowds but I always catch fish even BEFORE the rodeo.​
​
I've seen a lot of cars and a resident Great Blue Heron along Section 3 of the Perkiomen Creek for the last two weeks. If you go there on Opening Day and get skunked...​
​
...use that as an excuse. :)​

Thanks for the links Mike, it's interesting stuff!!
 
troutbert said:
If you put on your chest waders, wade as deep into the pool as possible, and thrash around with your wading staff, those trout might move.

The best time to do this is on opening day at 7:50 am.
Click to expand...
I usually get 10 of my friends together. We all get in the stream side by side the night before and drive the stockies a mile up stream. It’s like a deer drive but for fish. Camp out and get our limit the next day in about 15 minutes. Have the whole place to ourselves. Don’t tell anyone about this tactic. 😂😂😂
 
stocked trout should be float stocked. not sure is PA does that. if they do then kudos to them. otherwise stocked trout spread out during floods or high CFS from recent rains.
 
I recently checked out the creek that flows near the Ned Smith Center near Dauphin. I had heard it was recently stocked. It was clear enough I could see into most of it. I fished for about a mile downstream from top of it and saw one fish. Did not move any others. I think almost all those fish they put in are gone. Maybe downstream somewhere.
 
caddisflyer said:
I recently checked out the creek that flows near the Ned Smith Center near Dauphin. I had heard it was recently stocked. It was clear enough I could see into most of it. I fished for about a mile downstream from top of it and saw one fish. Did not move any others. I think almost all those fish they put in are gone. Maybe downstream somewhere.
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Interesting.

What stream is that? You "heard" it was recently stocked. Stocked by who? PFBC? If so, is it on their website?
 
Bamboozle said:
A couple of unscientific observations that probably mean nothing...

I fished Section 1 of Dyberry Creek once with the memories of a 1982 PA Angler article in my mind. I started in a beautiful part of the creek just above Section 2 the FFO water and I couldn't buy a fish while my two buddies were killing them about a mile upstream, I assume where they dumped the fish...​
​
I hate that creek...​
​
A few years ago I fished Section 2 of the West Branch of Chester Creek, a childhood favorite of mine. The only place I could catch anything was in a hole right next to Valleybrook Road...​
​
I have too many fond memories that creek to ever hate it... :)​
​
I fish Section 2 of French Creek in Chesco a couple of times a season because it's where I caught my first trout so it's extra special to me. It does see it share of crowds but I always catch fish even BEFORE the rodeo.​
​
I've seen a lot of cars and a resident Great Blue Heron along Section 3 of the Perkiomen Creek for the last two weeks. If you go there on Opening Day and get skunked...​
​
...use that as an excuse. :)​

Thanks for the links Mike, it's interesting stuff!!
Click to expand...
My Dyeberry Creek. I remember that article.
 
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