Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN, USA.
Lang Railsback & Associates, Arcata, CA, USA.
Sci Total Environ. 2019 Feb 1;649:949-959. doi: 10.1016/j.scitotenv.2018.08.344. Epub 2018 Aug 28.
We demonstrate how mechanistic modeling can be used to predict whether and how biological responses to chemicals at (sub)organismal levels in model species (i.e., what we typically measure) translate into impacts on ecosystem service delivery (i.e., what we care about). We consider a hypothetical case study of two species of trout, brown trout (Salmo trutta; BT) and greenback cutthroat trout (Oncorhynchus clarkii stomias; GCT). These hypothetical populations live in a high-altitude river system and are exposed to human-derived estrogen (17α‑ethinyl estradiol, EE2), which is the bioactive estrogen in many contraceptives. We use the individual-based model inSTREAM to explore how seasonally varying concentrations of EE2 could influence male spawning and sperm quality. Resulting impacts on trout recruitment and the consequences of such for anglers and for the continued viability of populations of GCT (the state fish of Colorado) are explored. inSTREAM incorporates seasonally varying river flow and temperature, fishing pressure, the influence of EE2 on species-specific demography, and inter-specific competition. The model facilitates quantitative exploration of the relative importance of endocrine disruption and inter-species competition on trout population dynamics. Simulations predicted constant EE2 loading to have more impacts on GCT than BT. However, increasing removal of BT by anglers can enhance the persistence of GCT and offset some of the negative effects of EE2. We demonstrate how models that quantitatively link impacts of chemicals and other stressors on individual survival, growth, and reproduction to consequences for populations and ecosystem service delivery, can be coupled with ecosystem service valuation. The approach facilitates interpretation of toxicity data in an ecological context and gives beneficiaries of ecosystem services a more explicit role in management decisions. Although challenges remain, this type of approach may be particularly helpful for site-specific risk assessments and those in which tradeoffs and synergies among ecosystem services need to be considered.
我们展示了如何利用机制模型来预测化学物质对模式物种（即我们通常测量的）的生物反应是否以及如何转化为对生态系统服务提供的影响（即我们关心的）。我们考虑了一个假设的案例研究，即两种鳟鱼，褐鳟（Salmo trutta；BT）和绿背山鳟（Oncorhynchus clarkii stomias；GCT）。这些假设的种群生活在高海拔河流系统中，暴露于人类来源的雌激素（17α-乙炔基雌二醇，EE2）中，EE2 是许多避孕药中的生物活性雌激素。我们使用基于个体的 inSTREAM 模型来探索季节性变化的 EE2 浓度如何影响雄性产卵和精子质量。然后，探讨了 EE2 对鳟鱼繁殖的影响，以及对钓鱼者和 GCT（科罗拉多州的州鱼）种群持续生存能力的影响。inSTREAM 结合了季节性变化的河流流量和温度、钓鱼压力、EE2 对特定物种的种群动态的影响以及种间竞争。该模型便于定量探索内分泌干扰和种间竞争对鳟鱼种群动态的相对重要性。模拟预测，恒定的 EE2 负荷对 GCT 的影响比对 BT 的影响更大。然而，钓鱼者对 BT 的大量捕捞可以增强 GCT 的持久性，并抵消 EE2 的一些负面影响。我们展示了如何将定量链接化学物质和其他胁迫因素对个体生存、生长和繁殖的影响与对种群和生态系统服务提供的后果的模型与生态系统服务估值相结合。这种方法有助于在生态背景下解释毒性数据，并使生态系统服务的受益者在管理决策中发挥更明确的作用。尽管仍然存在挑战，但这种方法可能特别有助于特定地点的风险评估，以及需要考虑生态系统服务之间的权衡和协同作用的情况。
