Spawning spring stocked PFBC RT seen today

[Dave_W]

Mike wrote:
Troutbert,
I waited until we sampled farther upstream to respond. A major part of the improvement is solely related to water temp improvements once a dam was removed. The fish population responded gradually. One big change from when the stream was surveyed in the late 1970's is that the substantial smallmouth population has disappeared. As the old impoundment site grew in with terrestrial vegetation and as the vegetation matured along the rest of the stream at the same time, it is clear that stream temps improved and that trout populations did as well. There is still more improvement possible, however, because the stream still supports a common shiner population, with the most being present closer to where the impoundment was located and a decline in numbers occurring farther downstream.

I doubt that the stream will support a Class A equivalent biomass in the future, as about a third of the two mile length that was surveyed using two representative sampling sites was impacted by substantial stormwater runoff and had predominantly pea gravel and sand substrate. It is unlikely that the two sites will ever average to the equivalent of a Class A biomass as a result and even the downstream site was only a low class B equivalent, but with a nice number of legal size fish. The downstream site was more ideal with less stormwater damage, good habitat, and a rocky substrate. Additionally, this is a stream that I shifted a decade ago to predominantly RT stocking, which may have also benefitted wild trout abundance.

For those concerned about RT spawning, I have had RT predominantly stocked in SE Pa for years and have only run into RT fingerlings on a few occasions. I have never run into a wild adult RT except in limestoners where we already knew that wild RT populations were present and perhaps in Codorus Ck.

Where have I seen RT fingerlings on occasions in stocked trout sections? Cold Run, trib to the Little Schuylkill, Beaver Ck, trib to Fishing Ck, York Co, Little Lehigh ( not Area 6)', Codorus Ck in the old days, and perhaps a handful of others where we might have recovered a single fish. This is also what I have seen when working statewide. Fall spawning of pa stocked RT is a big problem for over winter survival of fall production. Why the few fingerlings that are produced at times do not seem to survive is more of a mystery, but it could be related to cold water disease or generally poor adaptation to the wild.

Very interesting.
In your last sentence, what is meant by "coldwater disease"?

 

[ryansheehan]

Dave_W wrote:

Mike wrote:
Troutbert,
I waited until we sampled farther upstream to respond. A major part of the improvement is solely related to water temp improvements once a dam was removed. The fish population responded gradually. One big change from when the stream was surveyed in the late 1970's is that the substantial smallmouth population has disappeared. As the old impoundment site grew in with terrestrial vegetation and as the vegetation matured along the rest of the stream at the same time, it is clear that stream temps improved and that trout populations did as well. There is still more improvement possible, however, because the stream still supports a common shiner population, with the most being present closer to where the impoundment was located and a decline in numbers occurring farther downstream.

I doubt that the stream will support a Class A equivalent biomass in the future, as about a third of the two mile length that was surveyed using two representative sampling sites was impacted by substantial stormwater runoff and had predominantly pea gravel and sand substrate. It is unlikely that the two sites will ever average to the equivalent of a Class A biomass as a result and even the downstream site was only a low class B equivalent, but with a nice number of legal size fish. The downstream site was more ideal with less stormwater damage, good habitat, and a rocky substrate. Additionally, this is a stream that I shifted a decade ago to predominantly RT stocking, which may have also benefitted wild trout abundance.

For those concerned about RT spawning, I have had RT predominantly stocked in SE Pa for years and have only run into RT fingerlings on a few occasions. I have never run into a wild adult RT except in limestoners where we already knew that wild RT populations were present and perhaps in Codorus Ck.

Where have I seen RT fingerlings on occasions in stocked trout sections? Cold Run, trib to the Little Schuylkill, Beaver Ck, trib to Fishing Ck, York Co, Little Lehigh ( not Area 6)', Codorus Ck in the old days, and perhaps a handful of others where we might have recovered a single fish. This is also what I have seen when working statewide. Fall spawning of pa stocked RT is a big problem for over winter survival of fall production. Why the few fingerlings that are produced at times do not seem to survive is more of a mystery, but it could be related to cold water disease or generally poor adaptation to the wild.

Very interesting.
In your last sentence, what is meant by "coldwater disease"?

It's a bacterial disease, I've also heard it called tail rot before.

 

[troutbert]

Mike,
Thanks for the detailed and very interesting information.

 

[PennKev]

Mike wrote:
Additionally, this is a stream that I shifted a decade ago to predominantly RT stocking, which may have also benefitted wild trout abundance.

So stocking affects wild trout populations.

Interesting.

 

[JimKennedy]

Over the years in Maryland, I can recall two cases where hatchery rainbows have spawned successfully, resulting in small populations that were around for a few years but eventually died out.

Wild rainbows face big hurdles on the east coast. While they can tolerate relatively high water temperatures, even slightly higher than browns, they require the same temperature range as brook trout if they are to thrive in the wild. This relates similarly to dissolved oxygen levels; cold water holds more oxygen than warm, and rainbows require high oxygen to thrive (not just survive). Browns, meanwhile, can thrive in waters that routinely get into the upper 60s.

On the east coast, rivers and streams are a bit more apt to be acidic naturally and brook trout can tolerate a good deal more natural acid in the water than rainbows. (Clearly industrial acid, mine acid and acid rain are intolerable all around, but pine tannins are part of the reality for brook trout in a way that they aren't for rainbows.)

The two wild rainbow instances I can attest to were both in tailwater situations. One was Big Hunting Creek near Camp David, which is a tiny tailwater. In the rapids at the bend below the bridge and big hole just below the dam (for those familiar) some stocked rainbows spawned in the early 1980s (if memory serves) and there was hope among the fisheries biologists that they would establish a self sustaining rainbow population. Unfortunately, after a few years, the stream spawned rainbows faded away. It is unclear (to me) if there ever was a second successful spawn.

The other case was in the mid to late 1980s in Big Gunpowder Falls just below Prettyboy Dam where a self sustaining and fishable population of rainbows became established for a few years and there were a few years of successful spawning. This area is the swiftest and coldest water in the Gunpowder tailwater. It was so cold in that period (the cold water release and minimum flows were established in this period, resulting in a good fishery below Prettyboy) that the brown trout population that became established rarely produced fish of more than 12 inches because the growing season was very short for them and a lot of the food species larger fish (fallfish and chubs) were unable to thrive. The wild rainbows, meanwhile, were on a knife's edge and would have done better if the water had been even colder. Years after the wild rainbow population petered out, the cold water release was adjusted to make it slightly warmer, to better suit the massive brown trout population.
Another factor that greatly affects the rainbows is that stocked rainbows are to established populations of wild brown and brook trout what roaster chickens are to wild pheasants. They are birds of about the same size and from a common recent genetic ancestor, but a massive breasted, white feathered chicken isn't likely to survive in the wild and even less likely to establish a wild population. Hatchery rainbows are similarly limited in their ability to survive and reproduce in the wild.

As an aside, browns and brooks from hatchery broods are similarly ill-suited to reproduce and establish wild populations on their own. They will, however, go through the motions of spawning and in a situation where they can spawn with wild fish, will do so. This introduces fish farm trout genes to wild populations, which have the potential to weaken the wild strain. This is why it is bad to stock hatchery browns and brooks over solid and well established wild populations.

jk

 

[ryansheehan]

JimKennedy wrote:
Over the years in Maryland, I can recall two cases where hatchery rainbows have spawned successfully, resulting in small populations that were around for a few years but eventually died out.

Wild rainbows face big hurdles on the east coast. While they can tolerate relatively high water temperatures, even slightly higher than browns, they require the same temperature range as brook trout if they are to thrive in the wild. This relates similarly to dissolved oxygen levels; cold water holds more oxygen than warm, and rainbows require high oxygen to thrive (not just survive). Browns, meanwhile, can thrive in waters that routinely get into the upper 60s.

On the east coast, rivers and streams are a bit more apt to be acidic naturally and brook trout can tolerate a good deal more natural acid in the water than rainbows. (Clearly industrial acid, mine acid and acid rain are intolerable all around, but pine tannins are part of the reality for brook trout in a way that they aren't for rainbows.)

The two wild rainbow instances I can attest to were both in tailwater situations. One was Big Hunting Creek near Camp David, which is a tiny tailwater. In the rapids at the bend below the bridge and big hole just below the dam (for those familiar) some stocked rainbows spawned in the early 1980s (if memory serves) and there was hope among the fisheries biologists that they would establish a self sustaining rainbow population. Unfortunately, after a few years, the stream spawned rainbows faded away. It is unclear (to me) if there ever was a second successful spawn.

The other case was in the mid to late 1980s in Big Gunpowder Falls just below Prettyboy Dam where a self sustaining and fishable population of rainbows became established for a few years and there were a few years of successful spawning. This area is the swiftest and coldest water in the Gunpowder tailwater. It was so cold in that period (the cold water release and minimum flows were established in this period, resulting in a good fishery below Prettyboy) that the brown trout population that became established rarely produced fish of more than 12 inches because the growing season was very short for them and a lot of the food species larger fish (fallfish and chubs) were unable to thrive. The wild rainbows, meanwhile, were on a knife's edge and would have done better if the water had been even colder. Years after the wild rainbow population petered out, the cold water release was adjusted to make it slightly warmer, to better suit the massive brown trout population.
Another factor that greatly affects the rainbows is that stocked rainbows are to established populations of wild brown and brook trout what roaster chickens are to wild pheasants. They are birds of about the same size and from a common recent genetic ancestor, but a massive breasted, white feathered chicken isn't likely to survive in the wild and even less likely to establish a wild population. Hatchery rainbows are similarly limited in their ability to survive and reproduce in the wild.

As an aside, browns and brooks from hatchery broods are similarly ill-suited to reproduce and establish wild populations on their own. They will, however, go through the motions of spawning and in a situation where they can spawn with wild fish, will do so. This introduces fish farm trout genes to wild populations, which have the potential to weaken the wild strain. This is why it is bad to stock hatchery browns and brooks over solid and well established wild populations.

jk

You can convince me of alot of things but the Gunpowder being too warm for rainbows is not one of them, especially before the ability to draw warmer water. There are wild rainbow populations in plenty of places that get far warmer than the GP.

 

[ryansheehan]

Here are the temps for 3 straight years at the Parkton gauge. The temps don't make it over 60 that often.

 

[Dave_W]

I saw a group of stocked rainbows, including a palomino, going through the spawning motions on the First Fork DHALO in Potter County yesterday. They had a pretty good sized redd dusted out.

 

[FarmerDave]

Woohoo, might have some native palominos!

(joking of course).

 

[Nymph-wristed]

Wild rainbow from Fishing Creek? I was a long way from Lamar. This is from Tuesday of this week, and I may have landed another smaller one that I did not photograph.

 

[Swattie87]

Hatchery escapee from Tylersville with the floods this year? No way to tell.

 

[Nymph-wristed]

Swattie87 wrote:
Hatchery escapee from Tylersville with the floods this year? No way to tell.

Yeah, who knows, right? Just wondering if others had encounters. We were almost to Mill Hall, so a long way from both hatcheries.

 

[lycoflyfisher]

There were fingerling rainbows stocked a few years ago in fishing Creek and cedar run.

 

[afishinado]

Fishing Creek was always a place to fish with a good chance for a PA trout grand slam > ST, BT, RT. I've done it more than a few times on BFC.

It's not unusual to catch what appear to be YOY or older bows with parr marks in or close to the Narrows. No one knows for sure if the hatcheries in the Narrows area are responsible for them or natural reproduction.

 

[Nymph-wristed]

afishinado wrote:
Fishing Creek was always a place to fish with a good chance for a PA trout grand slam > ST, BT, RT. I've done it more than a few times on BFC.

It's not unusual to catch what appear to be YOY or older bows with parr marks in or close to the Narrows. No one knows for sure if the hatcheries in the Narrows area are responsible for them or natural reproduction.

Thanks, guys. That is what my buddy who guides in the area says too. He can't tell for sure, but is seeing more fish of all sizes that are looking wild not just pretty holdovers with white tipped fins and wide bodies like this other one I caught on Tuesday...

 

[Acristickid]

That area of BFC gets hatchery rainbows planted from the state.

 

[afishinado]

acristickid wrote:
That area of BFC gets hatchery rainbows planted from the state.

^ Sure nuff the Kid has the scoop > https://www.fishandboat.com/Fish/Stocking/Documents/FingerlingTroutStocking2018.pdf

 

[Nymph-wristed]

Yep, I finally look for the list. Thanks, again, fellas!

 

[kobalt335]

A few years ago they stocked rainbow fingerlings in BFC. I don't know if that program is still going or not.

 

[TYoung]

They are still stocking fingerlings in Fishing Creek. I caught a few earlier this year in the Gilmore Road section.