NEWPORT, Ore. – Researchers who created “family trees” for nearly 10,000 fish found that first-generation, wild-born descendants of hatchery-origin Chinook salmon in an Oregon river show improved fitness. The finding, based on data collected over 13 years, is encouraging for Chinook salmon recovery efforts, said Kathleen O’Malley, an associate professor at Oregon State University and the study’s senior author. In this study, fitness is measured by the number of adult offspring a fish produces, w...