How many hatcheries in PA

[Fish Sticks]

Using PA examples, if brown trout populations decreased in the Letort, Spring Creek, Little Juniata River, Bald Eagle Creek, that wouldn't cause an increase in native brook trout in those streams. Because they hold no brook trout. And what would cause a decrease would be declines in physical habitat, water quality and quantity. Not because brown trout aren't capable of maintaining self-sustaining populations in these landscapes. The same is surely true in Montana. The declines there are probably due to drought and man-made disturbances.

Carp, starlings, English sparrows have not been stocked for a long time, over a century, yet they still maintain large populations. If brown trout stocking had totally ended in 1940, there would still be large numbers of brown trout here in PA. Their populations are maintained by reproduction, not by stocking.

Non-native plants such as multi-flora rose, shrub honeysuckles, autumn olive and barberry are no longer "stocked" but they are they are spreading all over the place. The understory of Spring Creek and many other valley limestone streams is MOSTLY non-native shrubs.

I would say we also don’t know that a decline in brown trout in some of those streams would not cause an increase in native brook trout, atleast 3 seasons a year in some of the larger warmer ones. I know a brook trout subwatershed that’s over 85% Agriculture and mostly treeless along the majority of the water way with high eroding banks and they use all of it 4 seasons a year due to high spring input. This goes back to ground water not traditionally being factored into our ideas about what can be a brook trout stream.

Brook trout exist in tributaries to all those streams mentioned except the Letort and for a few of them the temperature is suitable year round and in all the food is abundant. Also to point out that In the case of spring creek and the Letort what’s that different from where some of the larger springs flow out of the ground (Benner,Bonny brook) than the other small spring creeks we have in this state that sustain native brook trout(most of these on private property and some in some fairly developed areas). Not much difference really.

I am not saying that these streams you mentioned are our best targets for native brook trout restoration and populations probably wouldn’t be anything to write home about fishing wise. It’s just hard to imagine that the brook trout in tiny headwater streams wouldn’t move down to take advantage of that food source if there are no browns. And remember
Browns are a barrier and your essentially removing a barrier if they were to
Decline as you said. I think the angling community would be surprised in general about where native brook trout could survive without invasive species if we were ever given the chance in some small streams/sub- watersheds.

 

[silverfox]

BT more complex than sparrows? Suggest reviewing the phylogenetic tree.

Right. Because we haven't manipulated sparrows through domestication have we? Have we meddled in their survival traits by selectively breeding for certain characteristics? Yes, based solely on the Linnaean system of taxonomy, you're correct.

 

[Fish Sticks]

Using PA examples, if brown trout populations decreased in the Letort, Spring Creek, Little Juniata River, Bald Eagle Creek, that wouldn't cause an increase in native brook trout in those streams. Because they hold no brook trout. And what would cause a decrease would be declines in physical habitat, water quality and quantity. Not because brown trout aren't capable of maintaining self-sustaining populations in these landscapes. The same is surely true in Montana. The declines there are probably due to drought and man-made disturbances.

Carp, starlings, English sparrows have not been stocked for a long time, over a century, yet they still maintain large populations. If brown trout stocking had totally ended in 1940, there would still be large numbers of brown trout here in PA. Their populations are maintained by reproduction, not by stocking.

Non-native plants such as multi-flora rose, shrub honeysuckles, autumn olive and barberry are no longer "stocked" but they are they are spreading all over the place. The understory of Spring Creek and many other valley limestone streams is MOSTLY non-native shrubs.

And your right that brown trout can sustain themselves without stocking that’s for sure. But much like in Montana right now they may do so for a time and then not be able to putting their long term populations at risk. It hasn’t even been a century and a half since they have been here. Chinook salmon had insane reproduction in western NY streams for decades but now we see the writing in the wall with them.

And in your statement of native brook trout would not increase if browns eventually lost their hold on the below waterways this study may give you a more realistic idea of what might happen if the browns left. Browns were removed and brook trout moved down out of the headwaters and recolonized the stream and increased in size. Adult survival increased but that was probably atleast something to do with hydrograph not the brown trout being removed.

(PDF) Long-term population demographics of native brook trout following manipulative reduction of an invader

PDF | Although laboratory studies have provided evidence for negative interactions between brook trout and brown trout, it is unknown how these... | Find, read and cite all the research you need on ResearchGate

www.researchgate.net

 

[silverfox]

Do you get paid by the word, sentence, or paragraph?

Do you remember learning about logical fallacies in college? Ad Hominem ring a bell?