Data from: Population structure and persistence of Pacific herring following the Great Tohoku earthquake

We evaluated the effect of the Great Tohoku earthquake, which occurred on
March 11, 2011 in Japan, on the genetic diversity and population structure
of Pacific herring (Clupea pallasii). Pacific herring (n = 4466) were
collected between 2003 and 2014 through more than 20 sampling events
during spawning periods at nine spawning sites throughout the Pacific
herring distribution range in Japan. We measured them and genotyped 3784
fish at five microsatellite loci. Following the tsunami, the sea-spawning
population at the center of the affected area was almost extirpated and
was replaced by a genetically distinct lagoon-spawning population from an
adjacent brackish lake. However, the pattern of gene flow was stable for
populations, with unique admixture proportions in local populations
despite the high gene flow (FST = 0.0184). Our results indicate that
Pacific herring in Japan spawn in a range of salinities and exchange genes
between local populations regardless of the spawning ecotypes. We
hypothesize that the combination of constant gene flow between local
populations from straying of spawners and spawning fidelity creates weak
but significantly differentiated stable population structure. This process
can allow restoration of the genetic characteristics of damaged
populations over many generations and can thereby promote the long-term
viability of marine fishes that have high gene flow.