Data from: Resurrecting an extinct salmon evolutionarily significant unit: archived scales, historical DNA, and implications for restoration

Archival scales from 603 sockeye salmon (Oncorhynchus nerka), sampled from
May to July 1924 in the lower Columbia River, were analyzed for genetic
variability at 12 microsatellite loci, and compared to 17 present-day O.
nerka populations—exhibiting either anadromous (sockeye salmon) or
non-anadromous (kokanee) life histories—from throughout the Columbia River
Basin, including areas upstream of impassable dams built subsequent to
1924. Statistical analyses identified four major genetic assemblages of
sockeye salmon in the 1924 samples. Two of these putative historical
groupings were found to be genetically similar to extant evolutionarily
significant units (ESUs) in the Okanogan and Wenatchee rivers (pairwise
FST = 0.004 and 0.002, respectively) and assignment tests were able to
allocate 77% of the fish in these two historical groupings to the
contemporary Okanogan River and Lake Wenatchee ESUs. A third historical
genetic grouping was most closely aligned with contemporary sockeye salmon
in Redfish Lake, Idaho, although the association was less robust (pairwise
FST = 0.060). However, a fourth genetic grouping did not appear to be
related to any contemporary sockeye salmon or kokanee population, assigned
poorly to the O. nerka baseline, and had distinctive early return
migration-timing suggesting that this group represented a putative
historical ESU originating in headwater lakes in British Columbia that was
likely extirpated sometime after 1924. The lack of a contemporary O. nerka
population possessing the genetic legacy of this extinct ESU indicates
that efforts to reestablish early-migrating sockeye salmon to the
headwater lakes region of the Columbia River will be difficult.