Snyder Marcía N, Schumaker Nathan H, Ebersole Joseph L, Dunham Jason, Comeleo Randy, Keefer Matthew, Leinenbach Peter, Brookes Allen, Cope Ben, Wu Jennifer, Palmer John, Keenan Druscilla
US Environmental Protection Agency, Western Ecology Division, 200 35 St., Corvallis, OR 97333.
US Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97331.
Landsc Ecol. 2019 Apr 1;34(4):737-754. doi: 10.1007/s10980-019-00804-z.
Diadromous fish populations in the Pacific Northwest face challenges along their migratory routes from declining habitat quality, harvest, and barriers to longitudinal connectivity. These stressors complicate the prioritization of proposed management actions intended to improve conditions for migratory fishes including anadromous salmon and trout.
We describe a multi-scale hybrid mechanistic-probabilistic simulation model linking migration corridor conditions to fish fitness outcomes. We demonstrate the model's utility using a case study of salmon and steelhead adults in the Columbia River migration corridor exposed to spatially- and temporally-varying stressors.
The migration corridor simulation model is based on a behavioral decision tree that governs individual interactions with the environment, and an energetic submodel that estimates the hourly costs of migration. Emergent properties of the migration corridor simulation model include passage time, energy use, and survival.
We observed that the simulated fishes' initial energy density, the migration corridor temperatures they experienced, and their history of behavioral thermoregulation were the primary determinants of their fitness outcomes. Insights gained from use of the model might be exploited to identify management interventions that increase successful migration outcomes.
This paper describes new methods that extend the suite of tools available to aquatic biologists and conservation practitioners. We have developed a 2-dimensional spatially-explicit behavioral and physiological model and illustrated how it can be used to simulate fish migration within a river system. Our model can be used to evaluate trade-offs between behavioral thermoregulation and fish fitness at population scales.
太平洋西北地区的洄游鱼类种群在其洄游路线上面临诸多挑战，包括栖息地质量下降、捕捞以及纵向连通性障碍。这些压力因素使得旨在改善洄游鱼类（包括溯河产卵的鲑鱼和鳟鱼）生存条件的拟议管理行动的优先级变得复杂。
我们描述了一个多尺度混合的机制 - 概率模拟模型，该模型将洄游廊道条件与鱼类健康结果联系起来。我们通过对哥伦比亚河洄游廊道中成年鲑鱼和虹鳟鱼的案例研究，展示了该模型的实用性，这些鱼类面临着时空变化的压力因素。
洄游廊道模拟模型基于一个行为决策树，该决策树控制个体与环境的相互作用，以及一个能量子模型，该子模型估计每小时的洄游成本。洄游廊道模拟模型的涌现特性包括洄游时间、能量使用和存活率。
我们观察到，模拟鱼类的初始能量密度、它们所经历的洄游廊道温度以及它们的行为体温调节历史是其健康结果的主要决定因素。利用该模型获得的见解可用于确定能够提高洄游成功率的管理干预措施。
本文描述了新方法，扩展了水生生物学家和保护从业者可用的工具套件。我们开发了一个二维空间明确的行为和生理模型，并说明了如何使用它来模拟河流系统内的鱼类洄游。我们的模型可用于评估种群尺度上行为体温调节与鱼类健康之间的权衡。
