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 FST 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.

本研究基于微卫星基因型（microsatellite genotypes）开展亲权分析（parentage analysis），以测定华盛顿州韦纳奇河（Wenatchee River）内5条主要产卵支流间奇努克鲑鱼（Oncorhynchus tshawytscha）的归巢率与离群洄游率。
本研究共分析2248尾野生个体（natural-origin fish）与11594尾孵化繁育个体（hatchery-origin fish），结果显示，野生个体回归其出生支流的归巢率因支流而异，区间为0%至99%。
在5条支流中任意一条投放的孵化繁育个体，其回归该投放支流的归巢率远低于野生个体，二者分别为71%与96%。
针对孵化放流个体，基于亲权分析得到的离群洄游率，与通过物理标记回收（physical tag recoveries）估算得到的结果一致。
各主要产卵支流间的离群洄游率，整体高于标记个体洄游至韦纳奇河流域（Wenatchee River watershed）以外区域的离群洄游率。
在韦纳奇河流域内，野生个体的离群洄游率显著受产卵支流与亲本起源的影响：孵化繁育亲鱼自然产卵产生的后代，其离群洄游率显著高于双亲均为野生个体的后代。
值得注意的是，170尾由两尾野生个体交配产生的后代中，无一流离其出生支流。
基于FST统计量的基因流间接估算值，与亲权分析得到的估算值呈显著相关，但数值更高。
各支流专属的有效种群大小（effective population size）估算值，同样与各支流内的产卵亲鱼数量呈显著相关。