Data from: Using parentage analysis to estimate rates of straying and homing in Chinook salmon (Oncorhynchus tshawytscha)

We used parentage analysis based on microsatellite genotypes to measure rates of homing and straying of Chinook salmon (Oncorhynchus tshawytscha) among five major spawning tributaries within the Wenatchee River, Washington. Based on analysis of 2248 natural-origin and 11594 hatchery-origin fish, we estimated that the rate of homing to natal tributaries by natural-origin fish ranged from 0% to 99% depending on the tributary. Hatchery-origin fish released in one of the five tributaries homed to that tributary at a far lower rate than the natural-origin fish (71% compared to 96%). For hatchery-released fish, stray rates based on parentage analysis were consistent with rates estimated using physical tag recoveries. Stray rates among major spawning tributaries were generally higher than stray rates of tagged fish to areas outside of the Wenatchee River watershed. Within the Wenatchee watershed, rates of straying by natural-origin fish were significantly affected by spawning tributary and by parental origin: progeny of naturally spawning hatchery-produced fish strayed at significantly higher rates than progeny whose parents were themselves of natural origin. Notably, none of the 170 offspring that were products of mating by two natural-origin fish strayed from their natal tributary. Indirect estimates of gene flow based on F¬ST statistics were correlated with but higher than the estimates from the parentage data. Tributary-specific estimates of effective population size were also correlated with the number of spawners in each tributary.本研究借助基于微卫星基因型（microsatellite genotypes）的亲权分析，对华盛顿州温纳奇河（Wenatchee River）内5条主要产卵支流中的奇努克鲑（Oncorhynchus tshawytscha）的归巢率与偏离率进行了测定。基于对2248尾自然起源（natural-origin）个体与11594尾孵化场起源（hatchery-origin）个体的分析，本研究估算得到：自然起源个体回归其出生地产卵支流的归巢率因支流不同而异，区间为0%至99%。在5条支流中某一条释放的孵化场起源个体，其回归该支流的归巢率远低于自然起源个体（分别为71%与96%）。对于孵化场放流个体，基于亲权分析得到的偏离率与通过物理标记回收估算得到的结果相一致。主要产卵支流间的个体偏离率，普遍高于标记个体向温纳奇河流域外区域的偏离率。在温纳奇河流域内，自然起源个体的偏离率受产卵支流与亲本起源的显著影响：自然产卵的孵化场亲鱼所产后代的偏离率，显著高于亲本均为自然起源的后代。值得注意的是，在170尾由两条自然起源个体交配产生的后代中，无一条个体偏离其出生地产卵支流。基于FST统计量的间接基因流估算值与亲权分析数据得到的估算值呈正相关，但数值更高。各支流专属的有效种群规模（effective population size）估算值，同样与每条支流中的产卵个体数量呈正相关。