Abstract：
Population models are increasingly used to predict population-level effects of chemicals. For trout, most toxicity data are available on early-life stages, but this may cause population models to miss true population-level effects. We predicted population-level effects of copper (Cu) on a brook trout (Salvelinus fontinalis) population based on individual-level effects observed in either a life-cycle study or an early-life stage study. We assessed the effect of Cu on predicted trout densities (both total and different age classes) and the importance of accounting for effects on the full life cycle compared with only early-life stage effects. Additionally, uncertainty about the death mechanism and growth effects was evaluated by comparing the effect of different implementation methods: individual tolerance (IT) versus stochastic death (SD) and continuous versus temporary growth effects. For the life-cycle study, the same population-level no-observed-effect concentration (NOECpop) was predicted as the lowest reported individual-level NOEC (NOECind; 9.5 µg/L) using IT. For SD, the NOECpop was predicted to be lower than the NOECind for young-of-the-year and 1-year-old trout (3.4 µg/L), but similar for older trout (9.5 µg/L). The implementation method for growth effects did not affect the NOECpop of the life-cycle study. Simulations based solely on the early-life stage effects within the life-cycle study predicted unbounded NOECpop values (≥32.5 µg/L), that is, >3.4 times higher than the NOECpop based on all life-cycle effects. For the early-life stage study, the NOECpop for both IT and SD were predicted to be >2.6 times higher than the lowest reported NOECind. Overall, we demonstrate that effects on trout populations can be underestimated if predictions are solely based on toxicity data with early-life stages. Environ Toxicol Chem 2024;43:1662-1676. © 2024 SETAC.
摘要：
人口模型越来越多地用于预测化学品的人口水平影响。对于鳟鱼来说,大多数毒性数据都在生命早期阶段，但这可能会导致人口模型错过真正的人口水平效应。我们根据在生命周期研究或早期生命阶段研究中观察到的个体水平效应，预测了铜（Cu）对溪鳟鱼（Salvelinusfontinalis）种群的种群水平效应。我们评估了铜对预测的鳟鱼密度（包括总量和不同年龄类别）的影响，以及与仅早期生命阶段的影响相比，考虑对整个生命周期的影响的重要性。此外,通过比较不同实施方法的效果来评估死亡机制和生长效应的不确定性：个体耐受性（IT）与随机死亡（SD）以及连续与暂时生长效应。对于生命周期研究，使用IT预测了相同的群体水平的未观察到的效应浓度(NOECpop)与最低报告的个体水平的NOEC(NOECind;9.5µg/L).对于SD，预测年幼鱼和1岁鳟鱼的NOECpop低于NOECind（3.4µg/L），但类似于老鳟鱼（9.5微克/升）。生长效应的实施方法不影响生命周期研究的NOECpop。仅基于生命周期研究中早期生命阶段效应的模拟预测了无限制的NOECpop值（≥32.5µg/L），也就是说,>3.4倍高于基于所有生命周期效果的NOECpop。对于生命早期阶段的研究，预测IT和SD的NOECpop比报告的最低NOECind高>2.6倍。总的来说,我们证明,如果预测仅基于生命早期阶段的毒性数据,则可能会低估对鳟鱼种群的影响.环境毒物化学2024；00：1-15。©2024SETAC。
