I don’t see a conflict between managing for more larger ST in a population and having greater genetic diversity. These two concepts are not mutually exclusive, particularly since I explained the specific options that could be used to produce larger ST and that all of those techniques would work within the existing ST populations (improve big fish habitat, increase forage, reduce rare cases of overharvest, etc). Hammer is a productive stream and where habitat would allow I would expect larger ST, like the one in the photo, could be produced.
It is not clear to me that you understand why significantly increasing the number of legal size ST in a population was an objective of the C&R ST reg package that failed. Likewise when others suggest that these populations were already good; therefore, the wrong populations were selected the reason for the study is again being misunderstood. The study was in response claims that there was a statewide ST overharvest problem, and in my experience, the most frequent specific complaint has been the statewide 5 fish creel limit. Statewide is just that…statewide! If it’s truly a statewide problem as was claimed, then conducting a study on statewide waters, especially public waters with both multiple control waters and multiple treatment waters, should reveal the problem and answer the question. One should not have to cherry pick suspected impacted waters.
The results did not surprise the staff. They corresponded with the low to no angler use on the vast majority of wild trout streams that all of us had seen over decades of fieldwork and corresponded with the low angler use and harvest that had been recorded in the statewide wild trout stream angler use and harvest study.
In the past you have mentioned or cited research that suggested inbreeding produces smaller ST. The argument might be more convincing if in the field ST adult size and adult habitat in Pa were commonly mismatched. In my experience, however, I don’t recall seeing that except perhaps in one very degraded, very infertile, mine acid or acid precip stream at a higher elevation in Schuylkill Co. In that case the entire population was low density as well for the available physical habitat so other factors were most likely at play.
While this inbreeding problem could in theory eventually occur, I think it’s a topic that possibly deserves more field research. I don’t think there is necessarily going to be much sympathy for moving fish around for genetic purposes after all of the efforts to finally develop a permitting system without stream specific genetic information to justify it, both from donor streams and recipients. I certainly don’t see it as an immediate critical problem in comparison to cooling streams down (buffers, as troutbert mentioned) in anticipation of climate change temperature impacts. After all, it takes years for planted trees to provide shade along a stream. When I say years, I’m referring to 10-15 that I have seen in more recent projects. The beauty of buffer development is that the streams benefit whether it’s the climate change “deniers” or the “believers” who are right.