Insights Real Research in Unexpected Places - Boat Ramps - Comments

[Dr. Courtney]

Dr. Courtney submitted a new PF Insights post

Real Research in Unexpected Places - Boat Ramps

Continue reading the Original PF Insights Post.

 

[Greg Bernhardt]

Great Insight! Please tell me you got to cook some of that trout you caught?

 

[jim mcnamara]

http://afs.tandfonline.com/doi/abs/10.1577/1548-8659(1979)108%3C277%3AEOSOGO%3E2.0.CO%3B2

Have you considered the effects of stocking on genetics? I have a casual acquaintance with some fisheries folks here in NM, and they believe that because they have to keep re-stocking, they are engendering all kinds of changes, side effects if you like, to existing populations. Gene pool changes are one of those they are concerned about. So what you saw in terms of lentic ( populations that cannot move far over generations/lifetimes compared to semi-anadromous (Coastal cuthroat trout) populations for example) may be related to other kinds of changes rather than competition.

 

[Dr. Courtney]

http://afs.tandfonline.com/doi/abs/10.1577/1548-8659(1979)108%3C277%3AEOSOGO%3E2.0.CO%3B2

Have you considered the effects of stocking on genetics? I have a casual acquaintance with some fisheries folks here in NM, and they believe that because they have to keep re-stocking, they are engendering all kinds of changes, side effects if you like, to existing populations. Gene pool changes are one of those they are concerned about. So what you saw in terms of lentic ( populations that cannot move far over generations/lifetimes compared to semi-anadromous (Coastal cuthroat trout) populations for example) may be related to other kinds of changes rather than competition.

Great points. In our own work in Colorado waters, there is so much stocking that genetic issues cannot be ruled out as a potential confounding factor. All the waters studied in Colorado are subject to heavy stocking (usually annually) and potential genetic effects.

However, our findings regarding competition are substantially similar to an earlier study in British Columbia lakes where the lakes were not subject to continuous restocking. See: http://www.nrcresearchpress.com/doi/abs/10.1139/f81-165#.WLA3oVXyvm4

On the whole, I tend to have faith that evolution, through selection pressure, can work with the available gene pools and restore semi-stable near equilibrium conditions as long as humans don't pull things too far out of whack with our meddling. The best genes only need a reasonable representation in the pool. Of course, this is more likely to be maintained in huge Colorado reservoirs with lots of tributaries, huge populations, and lots of self-sustaining subpopulations where the "put and take" trout fisheries are just added to the mix. Smaller, more isolated populations may be cause for greater concern.

Habitat destruction and extirpation of valuable species by overharvesting are my bigger worries.

 

[Dr. Courtney]

Great Insight! Please tell me you got to cook some of that trout you caught?

Of course.