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dc.contributor.authorWoody, Carol Annen_US
dc.date.accessioned2009-10-05T23:14:41Z
dc.date.available2009-10-05T23:14:41Z
dc.date.issued1998en_US
dc.identifier.otherb43303870en_US
dc.identifier.other42918881en_US
dc.identifier.otherThesis 47933en_US
dc.identifier.urihttp://hdl.handle.net/1773/5398
dc.descriptionThesis (Ph. D.)--University of Washington, 1998en_US
dc.description.abstractPopulations can differ in both phenotypic and molecular genetic traits. Phenotypic differences likely result from differential selection pressures in the environment, whereas differences in neutral molecular markers result from genetic drift associated with some degree of reproductive isolation. Two sockeye salmon, Oncorhynchus nerka, populations were compared using both phenotypic and genotypic characters, and causal factors were examined. Salmon spawning in a short (<3 km), shallow (<21 cm), clear, homogenous spring-fed study site spawned later, were younger, smaller, and produced fewer and smaller eggs than salmon spawning in a longer (∼80 km), deeper, stained, diverse, precipitation-dominated stream. Run timing differences were associated with differences in stream thermal regimes. Age and size at maturity differences are likely due to differences in age-specific mortality rates. Fish in the shallow spring-fed system suffered higher adult predation rates and exhibited greater egg to fry survival compared to fish in the precipitation-fed system. Salmon in both streams exhibited non-random nest site selection for deeper habitats and smaller substrates (≥2 to <64 mm mean diameter) relative to available habitat; fish from the precipitation system avoided low velocity habitats containing fine (<2 mm) substrates. Genetic comparisons of six microsatellite loci indicated that run time was a more effective reproductive isolating mechanism than geographical distance. Differences between and within the tributary spawning populations are discussed in terms of selection, genetic drift, and the homogenizing effects of gene flow. This study indicates important adaptive differences may exist between proximate spawning groups of salmon which should be considered when characterizing populations for conservation or management purposes.en_US
dc.format.extentviii, 117 p.en_US
dc.language.isoen_USen_US
dc.rightsCopyright is held by the individual authors.en_US
dc.rights.urien_US
dc.subject.otherTheses--Fisheriesen_US
dc.titleEcological, morphological, genetic, and life history comparison of two sockeye salmon populations, Tustumena Lake, Alaskaen_US
dc.typeThesisen_US


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