New tetranucleotide microsatellites for fine-scale discrimination among endangered chinook salmon (Oncorhynchus tshawytscha)

The unambiguous identification of Central Valley spring-run chinook salmon has become imperative since their proposed listing in 1998. The accuracy of methods used to assign individuals to their stock of origin is critical for understanding juvenile migration patterns and determining the success of protection measures. Existing microsatellites discriminate between the endangered winter-run and. other chinook but are insufficient to characterize phylogenetically less distinct runs. Here, we isolated and developed highly variable tetranucleotide microsatellites for the specific goal of increasing discriminatory power among closely related populations, providing a new power towards the reliable differentiation of nonwinter runs.