Hammer Creek, Lancaster County 1/28/2023

[sixfootfenwick]

Correct the reference condition in that SGL stretch would have likely been forested wet lands with multiple braided channels created by large wood in sections that are more like “hollows” where the stream is surrounded by wet lands and skunk cabage. Its not a very narrow valley in alot of places. I think the best thing for tbat section is just letting the trees mature and add LWD naturally.

There is already some of that taming place and an island exists in the middle of the game lands. Alot of these stream sections that are wooded just need time not habitat manipulations. Thats why the work i have been focused on is in bare farm land where cover crops, tree buffers, and flood plain connection is needed. And I try and try and try to avoid deep pools/structures because I am not volunteering my time for large adult trout, I’m doing it for species conservation of wild native brook trout and mottled sculpin.

You are probably right in your post.
I'll say though, any attempt on habitat natural or not is futile until that upper section is fixed. It's why I shared that watershed plan.

 

[JeffP]

I filed an RTK with FWS for survey and fin clip genetic data and they refused to divulge the survey because the author had not published yet(thought i was going to snoop a publication or something?) but I finally spoke with them on the phone and they told me they only found like 8-11 individuals. That is partially based on where they sampled. They dis not go above the game lands and there are multiple tributaries up there that contain brook trout. I know a farmers bridge that has a 10” brookie sitting under it all the time. The biggest brown trout in the system i have seen are also up there as well.

So where did they start and stop the survey? And when was the survey conducted. I think the fish in Hammer move a lot. That's pretty disappointing.

 

[Fish Sticks]

You are probably right in your post.
I'll say though, any attempt on habitat natural or not is futile until that upper section is fixed. It's why I shared that watershed plan.

Yea agreed it’ll just get blown out

 

[Fish Sticks]

So where did they start and stop the survey? And when was the survey conducted. I think the fish in Hammer move a lot. That's pretty disappointing.

It was September 2 years and was from below the nature conservancy below 322 up into the state game land on pumping station. My guess is a fair amount of brook trout were up un buffalo springs and the forested tribs on private property near obie and it was just limited sampling. I think they did hit at least some of lower walnut too. I watched them get an 11” brook trout out of the mainstem in the area described though so some were really big fish but that doesn’t help when your surveying for fin clips for a genotyping study.

 

[Fish Sticks]

ya know a real pandoras box PFBC could open that they never would….

since the smeal college of business recommended to cut fish and close hatcheries and they didn’t and are ,surprise surprise, still hemorrhaging money on the stocked trout program relative to license sales. They could cut fish on a rotating basis for 2-3 years in streams that have high conservation value (like a spring creek life history for native brook trout ) and survey to see if it results in increased wild repro.

I would imagine the prospect of doing such would make them very uneasy because in some cases it would become very apparent their hatchery fish especially and also the consumptive attention they attract at times are acting as a very large impairment. And if it works for one there would be pressure to do it on others.

Id love to see that on Hammer and test the idea that with habitat at a premium that removing thousands of stocked fish annually from the competition for that habitat would have no effect.

 

[sixfootfenwick]

ya know a real pandoras box PFBC could open that they never would….

since the smeal college of business recommended to cut fish and close hatcheries and they didn’t and are ,surprise surprise, still hemorrhaging money on the stocked trout program relative to license sales. They could cut fish on a rotating basis for 2-3 years in streams that have high conservation value (like a spring creek life history for native brook trout ) and survey to see if it results in increased wild repro.

I would imagine the prospect of doing such would make them very uneasy because in some cases it would become very apparent their hatchery fish especially and also the consumptive attention they attract at times are acting as a very large impairment. And if it works for one there would be pressure to do it on others.

Id love to see that on Hammer and test the idea that with habitat at a premium that removing thousands of stocked fish annually from the competition for that habitat would have no effect.

🤔
This is an interesting concept.

I think logically the answer is obvious and yes it would be a Pandora's Box.

Hammer would actually be a great test stream.

 

[Mike]

Stocked adult trout are not competing with fry and fingerlings for habitat, as they select differing habitat types/locations.

The impact of trout stocking on the wild trout population abundance comes most frequently in the form of by-catch and harvest and/or delayed-mortality of wild trout, and that has almost certainly declined from the pre-Operation Future years and the early 1990’s when Pa license sales hit their peak at 1.1 million. One must also remember that there was no trout stamp requirement at that time so around 90% of anglers said they fished for trout at least one time per year. Furthermore, the PFC/PFBC was stocking around 5.1 million adult trout at that time. Now it’s about 3.1 million. There was also a very strong harvest mentality, which is now quite reduced from that of that time period. There is little doubt that the combination of angling pressure, harvest, and stocking rates is greatly reduced from that of the past.

We already know what happens in Pa when stocking over wild trout is terminated, but it’s also likely that reduced stocking and angling pressure as described above has already benefited a number of populations if and where the impact of stocking was a limiting factor with regard to adult trout abundance and biomass. I have very serious doubts that any of the impact of STATE stockings is felt at the fry or fingerling level such that via that specific avenue the abundance of adult wild fish two to three years hence is any greater than without stocking.

 

[Fish Sticks]

Stocked adult trout are not competing with fry and fingerlings for habitat.

The impact of trout stocking on the wild trout population abundance comes most frequently in the form of by-catch and harvest and/or delayed-mortality of wild trout, and that has almost certainly declined from the pre-Operation Future years and the early 1990’s when Pa license sales hit their peak at 1.1 million. One must also remember that there was no trout stamp requirement at that time so around 90% of anglers said they fished for trout at least one time per year. Furthermore, the PFC/PFBC was stocking around 5.1 million adult trout at that time. Now it’s about 3.1 million. There was also a very strong harvest mentality, which is now quite reduced from that of that time period. There is little doubt that the combination of angling pressure, harvest, and stocking rates is greatly reduced from that of the past. We already know what happens in Pa when stocking over wild trout is terminated, but it’s also likely that reduced stocking and angling pressure as described above has already benefited a number of populations where the impact of stocking was a limiting factor with regard to adult trout abundance and biomass. I have serious doubts that any of the impact of STATE stockings was felt at the fry or fingerling level such that via that avenue the abundance of adult wild fish two to three years hence would have been any greater than without stocking.

Pa has bot reduced the overall amount of trout they stock in the commonwealth, its still around 6 million. They send trout to coops and that accounts for the difference in your number and mine.

like you said there isn’t hardly any habitat in that stretch to grow large adult fish. So how in your mind are these fry and large stocked fish with aggressive feeding behaviors not altering fry mortality which we know is the most sensitive life stage for native brook trout as far as mortality. Where has this been studied? If not is the potential interactions with millions of stocked invasive species stocked just as the fry emerge from the gravel not an issue based on a hunch?

 

[Mike]

No, because I specifically said STATE stockings above, meaning PFBC stockings from PFBC hatcheries. See my comments about private stockings and the one time that I saw a lack of reproduction and forage likely associated with such stockings on top of PFBC stockings. Making it worse was that it was in a C&R section. During my tenure there was no apparent control on numbers stocked by co-ops in specific stream/sections so I’m not about to say what impacts they may have had if sections received excessive numbers of fish. Furthermore, the number of co-op fish stocked years ago was much higher than today since there were more co-ops, so when STATE stocked fish amounted to 5.1 million, the co-op numbers were higher too.

Not even a concern based on a hunch. There are too many Pa streams past and present that were stocked intensively or are stocked today where reproduction was and is fine. Many were stocked at much higher rates and with greater frequency than today because they were stocked based on the old system of County trout allocations based on license sales within each county. My concern regarding immediate (meaning during the spring stocking period) stocking impacts on ST has been strictly at the harvest end of the life cycle, not at the reproduction end.

Excess young are produced as a species adaptation to all kinds of ecological variables. Why do you think so many species in the animal kingdom have such high fecundity, litter production, and reproductive rates? You want examples with Salmonids? Idaho study of stocked RT impacts on a wild RT population…no impact on any standard metric measured. Yellowstone Lake…greatly reduced invasive Lake Trout population. No impact on abundance of young invasive Lake Trout. Less young just survived at a higher rate than when more young were produced, so the impact of reduced adult fish on YOY abundance was a wash…a clear adaptation.

Additionally, see the info in the recent RT thread on the Kootenay River study and at what size RT become piscivorous in streams/rivers.

 

[Fish Sticks]

No, because I specifically said STATE stockings above, meaning PFBC stockings from PFBC hatcheries. See my comments about private stockings and the one time that I saw a lack of reproduction and forage likely associated with such stockings on top of PFBC stockings. Making it worse was that it was in a C&R section. During my tenure there was no apparent control on numbers stocked by co-ops in specific stream/sections so I’m not about to say what impacts they may have had if sections received excessive numbers of fish. Furthermore, the number of co-op fish stocked years ago was much higher than today since there were more co-ops, so when STATE stocked fish amounted to 5.1 million, the co-op numbers were higher too.

Not even a concern based on a hunch. There are too many Pa streams past and present that were stocked intensively or are stocked today where reproduction was and is fine. Many were stocked at much higher rates and with greater frequency than today because they were stocked based on the old system of County trout allocations based on license sales within each county. My concern regarding immediate (meaning during the spring stocking period) stocking impacts on ST has been strictly at the harvest end of the life cycle, not at the reproduction end.

Excess young are produced as a species adaptation to all kinds of ecological variables. Why do you think so many species in the animal kingdom have such high fecundity, litter production, and reproductive rates? You want examples with Salmonids? Idaho study of stocked RT impacts on a wild RT population…no impact on any standard metric measured. Yellowstone Lake…greatly reduced invasive Lake Trout population. No impact on abundance of young invasive Lake Trout. Less young just survived at a higher rate than when more young were produced, so the impact of reduced adult fish on YOY abundance was a wash…a clear adaptation.

Additionally, see the info in the recent RT thread on the Kootenay River study and at what size RT become piscivorous in streams/rivers.

See before you were using numbers(demographic data) and then you made a statement that brook trout populations were “fine” but this is the folly of fisheries management as we have learned the harm at looking at demographic data alone can do and ignoring conservation genetics. Based on casey weathers thesis (theres a real study) no those brook trout are not fine.

As for the demographic data you mentioned I want cause and effect and controlled studies not observational data. To assume that a population is “fine” because it exists and not being able to put a number to the number of fry not surviving due to stocked invasive species(via predation or competition) is not wise.

 

[JeffP]

Brook Trout in Hammer are not fine. From what I can see, they have virtually disappeared especially compared to the numbers 20 years ago. I think a number of things may be to blame. When I saw a bass chase a juvenile brookie out of the water, I wonder how many were eaten by bass and stocked trout. Obviously this is not based on research.

 

[Fish Sticks]

Brook Trout in Hammer are not fine. From what I can see, they have virtually disappeared especially compared to the numbers 20 years ago. I think a number of things may be to blame. When I saw a bass chase a juvenile brookie out of the water, I wonder how many were eaten by bass and stocked trout. Obviously this is not based on research.

Thank you!!!! Lol

The obvious observation that their disappearing in the setting of invasive predators with no research to prove continued stocking is not harmful to that water way as JeffP mentions should signal a problem if Pa fish and boat cared about rare life histories of brook trout like they probably say they do at EBTJV meetings

 

[Fish Sticks]

if you think all we need is reproduction then you need to watch this video from Dr. David Kazyak that just dropped today Mike. Its the best explanation of how brook trout population structure and long term persistence prospects are effected by things like choosing to ignore the magnitude of these fish’s true habitat and the harms of stocking invasive species over them(which can effect reproduction as well as evidenced HERE in Pennsylvania by Mark Kirks study in 73 northwestern PA streams using PFBC stocked brown trout locations).

 

[Mike]

No, this is the problem with these discussions. I didn’t say the populations were “fine;” I said reproduction was fine despite state stocking. There’s a big difference.

Second, show me a population of brook trout where reproduction is limited and by process of elimination the only or primary limiting factor is predation by stocked trout. There is not a single population of BT or ST among the many that I have surveyed where less than expected populations could not be explained by some physical or chemical variable, or in the “old days,” cropping of adult ST down to the minimum length limit by anglers fishing for stocked trout.

As for Kirk’s study, I was pretty much sold on that until those here familiar with local geographical or physical conditions chimed in with info that presented some reasonable confounding factors that may have not been considered in the study. The study still gives reason for pause.

As for the genetics video, suffice it to say that reviewed it.

I’ll only comment on one idea at this time, that of genetic rescue. As is stated, it’s moving a “small number” of animals from one population to another. My disagreement is the idea that BT in a downstream segment of stream are preventing ST in an upstream segment from moving to a receiving stream and then spreading their genetic information among other populations. My argument has been that 1) it takes low numbers of ST moving over a series of years to accomplish this, so only low numbers have to successfully run the BT gauntlet. And 2), given my experience with migratory fish, and using the anthropomorphic term “determination,” it is clear that migratory fish species and probably those segments of ST populations that are inclined to emigrate are strongly determined to get to where they need to go. I didn’t expect BT to entirely prevent ST movement when previously discussed in this forum and the Hoxmeier and Dieterman paper, also presented in this forum, noted that a higher percentage of ST outmigrated when mixed ST/ BT were present in the lower end of the study stream than after the BT were removed. My point is not really what percentage migrated when, but that they did in fact successfully move out of the system in the presence of BT. There may be other studies to the contrary, but then the generality that BT prevent ST emigration is not a generality that can be applied without qualifiers.

 

[Fish Sticks]

No, this is the problem with these discussions. I didn’t say the populations were “fine;” I said reproduction was fine despite state stocking. There’s a big difference.

Second, show me a population of brook trout where reproduction is limited and by process of elimination the only or primary limiting factor is predation by stocked trout. There is not a single population of BT or ST among the many that I have surveyed where less than expected populations could not be explained by some physical or chemical variable, or in the “old days,” cropping of adult ST down to the minimum length limit by anglers fishing for stocked trout.

As for Kirk’s study, I was pretty much sold on that until those here familiar with local geographical or physical conditions chimed in with info that presented some reasonable confounding factors that may have not been considered in the study. The study still gives reason for pause.

As for the genetics video, suffice it to say that reviewed it.

So if you saw the genetics video you see that stocked invasive trout are decreasing gene flow. As for reproduction if you stock brown trout and they displace native brook trout and displace them from the streamhow does not affect reproduction. Look at tom clarks study on kratzer and bilger run he documents brown trout(that look stocked in the video) decimating a brook trout population by predation. The number of individuals dropped over several years and reproduction of fish with a 2-3 year old life span in that creek are reproducing the same amount???? This is lunacy

 

[Fish Sticks]

Multiple studies that look at streams with brown trout and then after removal show brown trout decimate age zero brook trout, of course their eating fry

 

[Mike]

Multiple studies that look at streams with brown trout and then after removal show brown trout decimate age zero brook trout, of course their eating fry

I did not say that BT do not eat ST; they eat other BT too and it’s not a stretch to that ST are probably cannibalistic as well. My point was that I have not seen any studies where predation by BT on ST fry or fingerlings was the limiting factor on ST population size. I would buy territoriality or cross breeding effects on population size before I would buy predation.

As for the comment above regarding displacement, that wasn’t the topic. The original comment that I was responding to had to do with predation on fry by stocked trout.

Was any evidence from stomach analyses results presented in the Kratzer/Bilger video?

 

[Fish Sticks]

I did not say that BT do not eat ST; they eat other BT too and it’s not a stretch to that ST are probably cannibalistic as well. My point was that I have not seen any studies where predation by BT on ST fry or fingerlings was the limiting factor on ST population size. I would buy territoriality or cross breeding effects on population size before I would buy predation.

As for your nee comment above regarding displacement, that wasn’t the topic. The original comment that I was responding to had to do with predation on fry by stocked trout.

Well if brook trout get displaced because of invasive trout species that happen to be stocked downstream predating/outcompeting them like tom’s kratzer run study is documenting the there is no fry.

So if research done by Tom shows us age zero brook trout are being eaten by brown trout and the mass lost by the brook trout population that has lost numbers of individuals is the exact gain in the overall mass of the brown trout population with the SAME number of individuals your still going to try and act like browns eating brook trout has no effect on the population size or reproduction??

 

[Mike]

I did not say that BT do not eat ST; they eat other BT too and it’s not a stretch to that ST are probably cannibalistic as well. My point was that I have not seen any studies where predation by BT on ST fry or fingerlings was the limiting factor on ST population size. I would buy territoriality or cross breeding effects on population size before I would buy predation.

As for the comment above regarding displacement, that wasn’t the topic. The original comment that I was responding to had to do with predation on fry by stocked trout.

Was any evidence from stomach analyses results presented in the Kratzer/Bilger video?

As for the impairment of gene flow by stocked trout, I believe the discussion in the video has to do with situations where the stocked trout begin to reproduce.

In contrast, my comments above on the original topic of predation had to do with the same spring that the trout were stocked…the immediate impact of a given year’s stockies on ST fry. See #29 and #34 above. That’s why, for example, I used the Idaho example.

My comments about the stocking program to were not meant to be applied to stocked fish that have reproduced, creating a new and possibly competing population. And why that was relevant to Hammer in perhaps as much as the last decade is that it was only supposed to receive stockings of RT. That is true for 2023 as well (and it appears that the stocking frequency has been reduced to one time).

 

[Fish Sticks]

As for the impairment of gene flow by stocked trout, I believe the discussion in the video has to do with situations where the stocked trout begin to reproduce.

In contrast, my comments above on the original topic of predation had to do with the same spring that the trout were stocked…the immediate impact of a given year’s stockies on ST fry. See #29 and #34 above. That’s why, for example, I used the Idaho example.

My comments about the stocking program to were not meant to be applied to stocked fish that have reproduced, creating a new and possibly competing population. And why that was relevant to Hammer in perhaps as much as the last decade is that it was only supposed to receive stockings of RT. That is true for 2023 as well (and it appears that the stocking frequency has been reduced to one time).

I don’t believe the video was specific to only non stocked trout it never said that. It just said invasive species. Casey weathers thesis also did not differentiate. Stocked trout are actually put in at one of the best times of the year for brook trout to use dispersal corridors to facilitate gene flow