Diane G. Elliott S. Achord Ronald J. Pascho 1993 <p><span>Broodstock segregation based on the measurement of maternal </span><i>Renibacterium salmoninarum</i><span> infection levels by the enzyme-linked immunosorbent assay (ELISA) and the membrane filtration-fluorescent antibody technique (MF-FAT) was previously shown to affect the prevalence and levels of bacterial kidney disease (BKD) in progeny of chinook salmon, </span><i>Oncorhynchus tshawytscha</i><span> (Walbaum), during hatchery rearing. Subgroups of fish from that study were marked with passive integrated transponder (PIT) tags, and monitored by PIT-tag detectors during the first 342km of their migration to the Pacific Ocean. Differences in the recovery of tagged fish were significant (</span><i>P</i><span>≤ 0·01) at each detection point and became more pronounced as the fish moved downstream. Cumulative recoveries of fish from the low-BKD group and the high-BKD group, respectively, were 31% and 28% after 116km, 44% and 37% after 176km, and 51% and 42% after 342km. There were no apparent differences in the migration timing of the two groups to the first detection point. The data suggested that in-river survival was higher in the progeny group from parents that had low </span><i>R. salmoninarum</i><span> infection levels or tested negative for </span><i>R. salmoninarum</i><span> (low-BKD group) than in the group female parents with high infection levels (high-BKD group).</span></p> application/pdf 10.1111/j.1365-2109.1993.tb00537.x en Wiley Monitoring of the in-river migration of smolts from two groups of spring chinook salmon, <i>Oncorhynchus tshawytscha</i> (Walbaum), with different profiles of <i>Renibacterium salmoninarum</i> infection article