Salmonid Selection, Evolution, and Historical Abundance Patterns

Abstract

Pacific salmon represent an important group of species both from both cultural and economic perspectives. Given the importance of salmonids in marine and freshwater ecosystems, as a component of human food security, it is important to understand what natural and anthropogenic factors influence the evolutionary and demographic dynamics of population across their range, and develop quantitative tools to aid in the implementation of sustainable management practices. This dissertation is focused upon: (i) evaluating whether selective predation by brown bears (Ursus arctos) depends upon the density of their sockeye salmon (Oncorhynchus nerka) prey, (ii) quantifying strength and direction of natural and anthropogenic selection forces and life history tradeoffs that shaping optimal phenotypic distributions for populations of sockeye in Bristol Bay, Alaska, (iii) development of methods for reconstructing salmon run size by partitioning mixed-stock catches while accounting for differences in availability to harvest within common fishing areas and interception in spatially proximate terminal fishing districts using both age and genetic composition of catch data, (iv) simulation testing of a stage-structured statistical life cycle model for evaluating the natural and anthropogenic drivers of Chinook salmon (O. tshawytscha), and (v) an application for the statistical life cycle model to seven populations of fall and spring-run Chinook in the Sacramento River watershed of California.