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日发生于日本的东日本大地震（Great Tohoku earthquake）对太平洋鲱（Pacific herring, Clupea pallasii）遗传多样性与种群结构的影响。研究于2003年至2014年间，在日本太平洋鲱分布范围内的9处产卵场，于产卵季开展了20余次采样，共收集太平洋鲱个体4466尾（n=4466）。研究人员对采集样本进行了形态测量，并对其中3784尾个体的5个微卫星位点（microsatellite loci）进行了基因分型。海啸发生后，受灾区域中部的海产卵种群几乎灭绝，随后被邻近咸水湖中遗传特征显著分化的潟湖产卵种群所替代。尽管种群间存在较高的基因流（gene flow, FST=0.0184），但局部种群仍保有独特的遗传混合比例，整体种群的基因流模式保持稳定。本研究结果显示，日本海域的太平洋鲱可在不同盐度环境下产卵，且无论其产卵生态型（spawning ecotypes）如何，均会与当地种群发生基因交流。我们提出如下假说：产卵亲体的扩散洄游导致局部种群间持续的基因流，加之产卵位点保真行为，二者共同作用形成了分化程度微弱但具有统计学显著性的稳定种群结构。该过程可使受损种群的遗传特征在多代繁衍后得以恢复，进而有助于维持高基因流海洋鱼类的长期生存能力。