PETITION for Catch and Release on the TULLY!

[Mike]

Afish,
Thank you for the reference and abstract. The West Virginia University one has been recently published (reference below) in a respected, peer reviewed scientific journal, the Transactions of the American Fisheries Society and, as your abstract indicates, in comparing the Kamloop, Wytheville, and Case Western strains, when the fish were acclimated to 20 C (68 deg F) the critical thermal maximum for the Case Western strain was only 0.3 degrees F (.15 deg C) higher than for the worst performer, the Kamloop strain. "Worst" is a matter of one-and-a-half tenths of a degree F. This was statistically significant, but probably not biologically significant.

Note: This is not the 5-8 degree F better thermal tolerance mentioned above in #78, so I am wondering where that number originated.

In addition, the Case Western strain performed poorer in feeding and growth at 20 deg and 22 deg C. This is important in the Tully tail-race because the 8AM temperature objective at the gauge is 20 deg C (68 deg F) once mixing cold water from the bottom of Blue Marsh begins in late spring. The temperature does not usually fall below that once mixing begins. With a lower temperature objective, the lake would run out of cold water even sooner. In effect, we have pushed the Tully trout as far as we can, as 68 deg is where the stress begins.

Hartman, K and M. Porto. 2014. Thermal Performance of Three Rainbow Trout Strains at Above-Optimal Temperatures. Trans Am Fish Soc 143(6): 1145-1454.

 

[Fishidiot]

Yes - interesting study. Thanks for the link Afish.

I had not heard of the Case Western RTs and was skeptical of the temperature claims made further up the thread. I do believe that some western RTs are known for tolerance of higher temps but these are rather small differences. Although the study suggests, as Mike points out, only very small differences. . . I do think experimenting with some different trout in the Tully might be a worthwhile effort and might reveal some interesting changes.

 

[dshaffer]

I understand there are studies, but there is also a 20 year history of the Yough where they have been using these "warm water" RT successfully. Empirical results are part of science, too.

 

[troutbert]

The trout that seems to do very well on warmish "marginal" waters in PA and in many other places are the wild brown trout.

I know some places that have good smallmouth bass fishing AND good wild brown trout fishing, in exactly the same stretch of water.

Maybe stocking wild strain fingerling browns would be worth a try on the Tully.