Record Details
Patterns of genetic inheritance and variation through ontogeny for hatchery and wild stocks of Chinook salmon
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Patterns of genetic inheritance and variation through ontogeny for hatchery and wild stocks of Chinook salmon |
| Names |
Hulett, Patrick L.
(creator) Schreck, Carl B. (advisor) Li, Hiram W. (advisor) |
| Date Issued | 1991-03-12 (iso8601) |
| Note | Graduation date: 1991 |
| Abstract | Although differences between selective pressures in hatcheries and streams have been theorized to cause genetic divergence between hatchery and wild salmonids, evidence of this is lacking. This study was initiated to document the presence or absence of genetic change in hatchery and wild stocks by characterizing genetic traits in fish of various life history stages within a single generation. Nine biochemical traits (enzyme loci) and 12 meristic traits were characterized for adult fall chinook and one or more juvenile stages of their progeny of the 1984 brood year. Study groups consisted of hatchery-reared and naturally-reared subunits of populations in two tributaries of the lower Columbia River: Abernathy Creek and the Lewis River. Parents of both groups from Abernathy Creek were primarily of hatchery origin, whereas parents of both groups from the Lewis River were primarily of wild origin. The experimental design thus included reciprocal comparisons of hatchery and wild-reared groups from each of two stocks: one that has been propagated under hatchery conditions for at least five generations and one that has evolved in a stream environment. Both biochemical and meristic traits varied among adult and juvenile stages within hatchery and wild groups. Changes in some of these traits appear to have been caused by natural selection. This was true even for Abernathy hatchery and Lewis wild groups, which have been in the same environment for many generations. The direction and/or degree of change in some biochemical and meristic traits differed between hatchery and wild groups from a given stream, suggesting that selective pressures of the hatchery and wild environments differed in those cases. However, it could not be determined from these data whether the observed divergence of traits reflects general differences in hatchery and stream environments, or if it reflects population-specific responses to site-specific environmental conditions. The extent to which patterns of genetic change within a single generation might vary among year classes or generations is likewise unknown. Evidence of temporal changes in biochemical and meristic traits of hatchery and wild fish within a single generation has important implications regarding the use of those traits to characterize stocks. Assumptions of temporal stability of biochemical or meristic traits within or between year classes should be applied with caution. Sampling strategies of studies involving these characters should account for the possibility of temporal heterogeneity. Finally, these results suggest that workers using allozymes as genetic tags should test the assumption of selective neutrality of the particular allozyme markers being used. |
| Genre | Thesis/Dissertation |
| Topic | Fishery resources -- Hatchery vs. wild stocks |
| Identifier | http://hdl.handle.net/1957/37931 |
