Lahontan Cutthroat Trout (LCT) Oncorhynchus clarkii henshawi have experienced some of the most marked reductions in abundance and distribution among Cutthroat Trout subspecies. The population of LCT in Pyramid Lake, Nevada has returned from the brink of extirpation, and although it is highly managed via stocking, the population is thriving and has recently started to reproduce naturally. Our objectives were to determine (1) whether predator and prey remain tightly coupled, (2) whether LCT are food limited, and (3) the status of the LCT population with regard to the potential prey-based contemporary carrying capacity. We used a multifaceted approach, including intensive field sampling of fish, bioenergetics modeling, cohort reconstruction, and comparisons of prey availability to consumption. We estimated that the average population of LCT in Pyramid Lake is 1.2 million, average annual stocking is 650,000, and the number of fish angled ranges from 5,000 to 14,000 per year, with a 90% release rate. Driven by seasonal and size variation in consumption, individual annual consumption by LCT varied from 667 to 992 g/year for small LCT (200–400 mm TL) and from 2,388 to 3,057 g/year for large LCT (>400 mm TL). Lahontan Cutthroat Trout are consuming, on average, 14–63% of the standing crop of Tui Chub Siphateles bicolor annually, indicating that LCT are currently not exceeding their prey-based carrying capacity. The LCT in Pyramid Lake remain tightly coupled to their primary native prey, Tui Chub, despite considerable changes to the ecosystem; therefore, managing for a robust population of LCT translates largely to managing for forage fish. This supply-versus-demand issue is of particular concern for Pyramid Lake given that the density of Tui Chub may be declining concordant with declining lake elevation. Given the conservation importance of this LCT population, careful monitoring is critical; however, “predation inertia” indicates that effective short-term management in response to fluctuations in forage fishes is likely possible.

中文翻译：

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在重要的重新引入的拉洪坦割喉鳟鱼种群中探索捕食者和猎物之间的当代关系

Lahontan Cutthroat Trout (LCT) Oncorhynchus clarkii henshawi在割喉鳟鱼亚种中经历了一些最显着的丰度和分布减少。内华达州金字塔湖的 LCT 种群已经从灭绝的边缘回归，虽然通过放养对其进行了高度管理，但种群数量正在蓬勃发展，最近开始自然繁殖。我们的目标是确定 (1) 捕食者和猎物是否保持紧密耦合，(2) LCT 是否受到食物限制，以及 (3) LCT 种群在潜在的基于猎物的当代承载能力方面的状况。我们使用了多方面的方法，包括对鱼类进行密集现场采样、生物能量学建模、队列重建以及猎物与消费量的比较。我们估计金字塔湖LCT的平均人口为120万，年均放养量为65万，成角鱼的数量从每年 5,000 到 14,000 条不等，释放率达 90%。受消费的季节性和大小变化的驱动，小型 LCT（200-400 毫米 TL）的 L​​CT 个人年消费量从 667 到 992 克/年不等，大型 LCT（>400 毫米 TL）的个人年消费量从 2,388 到 3,057 克/年不等。Lahontan Cutthroat Trout 平均消耗了 Tui Chub 立秋作物的 14-63%Siphateles bicolor每年，表明 LCT 目前没有超过其基于猎物的承载能力。尽管生态系统发生了相当大的变化，但金字塔湖中的 LCT 仍然与其主要的本地猎物 Tui Chub 紧密结合；因此，管理强大的 LCT 种群在很大程度上转化为管理饲料鱼。考虑到 Tui Chub 的密度可能随着湖泊海拔的下降而下降，这种供需问题对 Pyramid Lake 来说尤其令人担忧。鉴于此 LCT 种群的保护重要性，仔细监测至关重要；然而，“捕食惯性”表明针对饲料鱼的波动进行有效的短期管理是可能的。