Castellani Marco, Heino Mikko, Gilbey John, Araki Hitoshi, Svåsand Terje, Glover Kevin A
Department of Engineering University of Birmingham Birmingham UK.
Department of Biological Sciences University of Bergen Bergen Norway.
Evol Appl. 2018 Mar 23;11(6):1010-1025. doi: 10.1111/eva.12615. eCollection 2018 Jul.
Genetic interaction between domesticated escapees and wild conspecifics represents a persistent challenge to an environmentally sustainable Atlantic salmon aquaculture industry. We used a recently developed eco-genetic model (IBSEM) to investigate potential changes in a wild salmon population subject to spawning intrusion from domesticated escapees. At low intrusion levels (5%-10% escapees), phenotypic and demographic characteristics of the recipient wild population only displayed weak changes over 50 years and only at high intrusion levels (30%-50% escapees) were clear changes visible in this period. Our modeling also revealed that genetic changes in phenotypic and demographic characteristics were greater in situations where strayers originating from a neighboring wild population were domestication-admixed and changed in parallel with the focal wild population, as opposed to nonadmixed. While recovery in the phenotypic and demographic characteristics was observed in many instances after domesticated salmon intrusion was halted, in the most extreme intrusion scenario, the population went extinct. Based upon results from these simulations, together with existing knowledge, we suggest that a combination of reduced spawning success of domesticated escapees, natural selection purging maladapted phenotypes/genotypes from the wild population, and phenotypic plasticity, buffer the rate and magnitude of change in phenotypic and demographic characteristics of wild populations subject to spawning intrusion of domesticated escapees. The results of our simulations also suggest that under specific conditions, natural straying among wild populations may buffer genetic changes in phenotypic and demographic characteristics resulting from introgression of domesticated escapees and that variation in straying in time and space may contribute to observed differences in domestication-driven introgression among native populations.
养殖逃逸鱼与野生同类之间的基因相互作用，对环境可持续的大西洋鲑鱼养殖业构成了持续挑战。我们使用了最近开发的生态遗传模型（IBSEM），来研究野生鲑鱼种群在受到养殖逃逸鱼产卵入侵时的潜在变化。在低入侵水平（5%-10%的逃逸鱼）下，受体野生种群的表型和种群统计学特征在50年内仅表现出微弱变化，只有在高入侵水平（30%-50%的逃逸鱼）下，这一时期才会出现明显变化。我们的模型还显示，当来自邻近野生种群的洄游鱼与驯化鱼混合且与目标野生种群同时发生变化时，表型和种群统计学特征的基因变化比未混合时更大。虽然在许多情况下，养殖鲑鱼入侵停止后，表型和种群统计学特征会出现恢复，但在最极端的入侵情况下，种群会灭绝。基于这些模拟结果以及现有知识，我们认为，养殖逃逸鱼产卵成功率降低、自然选择清除野生种群中适应不良的表型/基因型以及表型可塑性，共同缓冲了野生种群在受到养殖逃逸鱼产卵入侵时表型和种群统计学特征变化的速率和幅度。我们的模拟结果还表明，在特定条件下，野生种群之间的自然洄游可能缓冲养殖逃逸鱼基因渗入导致的表型和种群统计学特征的基因变化，并且洄游在时间和空间上的变化可能导致观察到的本地种群间驯化驱动的基因渗入差异。
