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.本研究评估了2011年3月11日日本发生的东日本大地震（Great Tohoku earthquake）对太平洋鲱（Pacific herring, Clupea pallasii）的遗传多样性与种群结构的影响。研究于2003年至2014年间，在日本境内太平洋鲱的整个分布范围内的9处产卵场，于产卵季开展了20余次采样，共收集太平洋鲱样本4466尾（n=4466）。研究人员对所有样本进行了形态测量，并对其中3784尾个体的5个微卫星（microsatellite）位点进行了基因分型。海啸发生后，受灾区域核心地带的海生产卵种群几乎局部灭绝，取而代之的是来自邻近咸淡水湖泊、遗传特征显著分化的潟湖产卵种群。尽管种群间基因流水平较高（FST=0.0184），但本地种群仍保留独特的遗传混合比例，种群间的基因流模式整体保持稳定。本研究结果显示，日本海域的太平洋鲱可在不同盐度梯度的环境中产卵，且无论其产卵生态型如何，均可在不同本地种群间发生基因交流。我们提出如下假说：产卵个体的洄游导致本地种群间持续存在基因流，加之产卵场所的忠实性，二者共同作用形成了分化程度微弱但统计上显著且稳定的种群结构。这一过程可使受损种群的遗传特征在多代繁衍中得以恢复，进而助力具有高基因流特性的海洋鱼类实现长期种群存续。