Pacific salmon hatcheries support important commercial fisheries for Pink Salmon Oncorhynchus gorbuscha and Chum Salmon O. keta in Prince William Sound (PWS), Alaska. State policy mandates that hatchery‐produced fish must not negatively impact natural populations, which can occur during mixed fisheries and via ecological and genetic interactions. Therefore, we quantified the spatial and temporal overlap of natural‐ and hatchery‐origin salmon (1) as they migrated into PWS and (2) in PWS spawning streams. Intensive sampling during 2013–2015, combined with ancillary agency harvest and hatchery composition data, also allowed us to estimate the hatchery, natural, and total run sizes. Estimated annual proportions (SE in parentheses) of hatchery fish in the preharvest run ranged from 0.55 (0.01) to 0.86 (0.03) for Pink Salmon and from 0.51 (0.03) to 0.73 (0.02) for Chum Salmon. Proportions of hatchery fish across all sampled PWS spawning streams were much lower, ranging from 0.05 (0.03) to 0.15 (0.07) for Pink Salmon and from 0.03 (0.03) to 0.09 (0.03) for Chum Salmon. In both species, relatively high instream proportions of hatchery fish tended to be geographically localized, while many streams exhibited low proportions. The estimated total PWS runs were 50–142 million Pink Salmon and 2.3–5.4 million Chum Salmon. Commercial fisheries harvested 94–99% of hatchery‐origin fish of both species, 27–50% of natural‐origin Pink Salmon, and 17–20% of natural‐origin Chum Salmon. Despite very high harvest rates on hatchery‐produced fish, an estimated 0.8–4.5 million hatchery Pink Salmon and 30,000–90,000 hatchery Chum Salmon strayed into PWS spawning streams. Our findings provide context for further research on the relative productivity of hatchery‐ and natural‐origin salmon spawning in streams, density‐dependent survival, improvements in fidelity to hatchery release sites, the influence of hatchery production on escapement management and policy, and refinements in harvest management precision in PWS.

中文翻译：

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2013–2015年返回阿拉斯加威廉王子湾的粉红鲑鱼和大鲑鱼的孵化场-原始流浪率和总游走特性

太平洋鲑鱼孵化场为粉红鲑鱼Oncorhynchus gorbuscha和Chum鲑鱼O. keta的重要商业渔业提供了支持在阿拉斯加的威廉王子湾（PWS）。国家政策规定，孵化场生产的鱼不得对自然种群产生负面影响，这可能在混合渔业中以及通过生态和遗传相互作用而发生。因此，我们对天然和孵化场鲑鱼（1）迁移到PWS中和（2）在PWS产卵流中的时空重叠进行了量化。2013-2015年期间的密集采样，结合机构的辅助收获和孵化场组成数据，也使我们能够估算出孵化场，自然孵化场和总运行规模。粉红鲑鱼孵化前的孵化场鱼类年估计比例（括号中的SE）为0.55（0.01）至0.86（0.03），而鲑鱼为0.51（0.03）至0.73（0.02）。在所有采样的PWS产卵流中，孵化场鱼类的比例要低得多，为0。粉红鲑鱼从05（0.03）到0.15（0.07），粗鲑鱼从0.03（0.03）到0.09（0.03）。在这两个物种中，孵化鱼的相对较高的入流比例往往在地理上是局部的，而许多溪流的孵化率却较低。估计PWS总运行量为50–1.42亿只粉红鲑鱼和230–540万只“鲑鱼”。商业渔业捕捞这两种物种的孵化场鱼类的比例为94–99％，天然起源的粉红鲑鱼的比例为27–50％，天然起源的鲑鱼的比例为17–20％。尽管孵化场生产的鱼的收成率很高，但估计有0.8–450万个孵化场的粉鲑和30,000–90,000个孵化场的鲑鱼流失到了PWS产卵流中。我们的发现为进一步研究溪流中孵化场和天然鲑鱼产卵的相对生产力，依赖密度的生存，