Simultaneous management actions often are used to improve the status of imperiled species, yet the effects of these actions can be difficult to determine. The endangered Rio Grande Silvery Minnow Hybognathus amarus is a short‐lived fish with a dispersive life history and thus requires—but does not occupy—unfragmented habitat for recruitment and survival. We used Rio Grande Silvery Minnow as a model system for an individual‐based simulation study to evaluate responses of genetic effective size to hatchery supplementation and fish passage in a managed population. Simulations were designed to test effects of fish passage on the relationship between estimates of inbreeding (N_eI) and variance (N_eV) effective sizes, which differ consistently (N_eI >> N_eV) in long‐term genetic‐monitoring data from hatchery‐supplemented Rio Grande Silvery Minnow populations. Values of different effective population size measures should be identical in a demographically stable and connected (admixed) population but can differ substantially under nonequilibrium conditions. When a barrier prevented upstream dispersal, N_eI was associated negatively with rate of downstream dispersal and positively with supplementation rate, whereas N_eV was associated negatively with both. This mirrored observations from Rio Grande Silvery Minnow. Individual effects of dispersal and supplementation, however, were difficult to discern due to significant interaction between these factors. When connectivity was restored, N_eI and N_eV depended on supplementation rate, with positive association between N_eI and supplementation rate versus a negative association for N_eV and interaction terms, and effects of dispersal were nonsignificant. Although fish passage did not alter the difference between N_eI and N_eV, our study suggests that for Rio Grande Silvery Minnow, and potentially other intensively managed species in regulated rivers, fish passage may help to distinguish effects of management actions, such as supplementation, from effects of other demographic influences. More generally, explicit analytical consideration of differences in effective population size estimates can provide important details of genetic responses to management.

中文翻译：

---

模拟种群里约格兰德银小Min鱼的有效规模与孵化场补充和栖息地连通性的关系

通常同时采取管理措施来改善受威胁物种的状况，但这些措施的效果可能难以确定。濒临灭绝的里奥格兰德州银色Min鱼Hy是一种短寿命的鱼类，具有悠久的生活史，因此需要（但不占用）未分片的栖息地进行募集和生存。我们使用Rio Grande Silvery Minnow作为基于个体的模拟研究的模型系统，以评估管理种群中遗传有效大小对孵化场补充和鱼类通过的反应。设计模拟以测试鱼类通过对近亲估计（N _eI）和方差（N _eV）之间关系的影响）有效规模，在孵化场补充的里奥格兰德州Silvery Minnow种群的长期遗传监测数据中，差异始终很大（N _eI  >>  N _eV）。在人口稳定和联系（混合）的人口中，不同有效人口规模量度的值应相同，但在非平衡条件下可能存在显着差异。当屏障阻止上游扩散时，N _eI与下游扩散率负相关，而与补充率正相关，而N _eV与下游扩散率负相关。与两者都负相关。这反映了里奥格兰德·银米诺的观察。然而，由于这些因素之间的显着相互作用，很难分辨出分散和补充的个体作用。当恢复连接性，Ñ _EI和Ñ _eV的依赖于补充率，与之间的正相关Ñ _EI和补充速率对用于负关联Ñ_电子伏特和相互作用项，和分散的效果不显着的人。尽管鱼类通过并没有改变N _eI和N _eV之间的差异，我们的研究表明，对于Rio Grande Silvery Minnow以及受管制河流中可能存在的其他集约化管理物种，鱼类通过可能有助于将管理行动（例如补充）的影响与其他人口影响的影响区分开。更一般而言，对有效种群规模估计值差异的明确分析考虑可以为管理提供遗传反应的重要细节。