Water quality standards based on sub-lethal effects and performance optima for aquatic organisms, rather than onset of mortality, are more ecologically relevant for management of species of conservation concern. We investigated the effects of hypoxia, temperature (with acclimation), nitrogenous chemical compounds, and chloride on Topeka shiners (Notropis topeka) by monitoring behavioral responses to a reduction in oxygen and, using swimming speed, determining thermal optima and onset of effect for concentrations of nitrogenous compounds and chloride. We found ASR₅₀ (i.e., dissolved oxygen concentrations where 50% of fish use aquatic surface respiration) to be 1.65 mg/L and ASR₉₀ to be 1.08 mg/L of dissolved oxygen. Optimum temperatures for the species ranged from 17.7 to 28.0 °C, while predicted 100% mortality ranged from 33.7 to 40.3 °C, depending on the temperature at which fish were acclimated prior to experiments. Ammonia and sodium chloride reduced swimming speed at concentrations below known LC₅₀ values, while nitrite concentrations did not correspond with swimming speed, but rather, post-experiment mortality. This provides insight into where Topeka shiners can not only persist, but also thrive. Although swimming speed may not be a suitable metric for determining the effects of all contaminants, our focus on optima and sub-lethal effects over tolerance allows selections of the most suitable reintroduction site matching the species’ physiological profile.

基于对水生生物的亚致死效应和性能优化的水质标准，而不是死亡的发生，与保护关注物种的管理在生态上更相关。我们通过监测对氧气减少的行为反应，并使用游泳速度，确定热最佳值和浓度效应的开始，研究了缺氧、温度（适应环境）、含氮化合物和氯化物对托皮卡（Notropis topeka）的影响含氮化合物和氯化物。我们发现 ASR ₅₀（即 50% 的鱼使用水面呼吸时的溶解氧浓度）为 1.65 mg/L 和 ASR ₉₀为 1.08 mg/L 的溶解氧。该物种的最佳温度范围为 17.7 至 28.0 °C，而预测的 100% 死亡率范围为 33.7 至 40.3 °C，具体取决于实验前鱼的适应温度。氨和氯化钠在低于已知 LC ₅₀值的浓度下会降低游泳速度，而亚硝酸盐浓度与游泳速度无关，而是与实验后死亡率相对应。这让我们深入了解托皮卡闪耀者不仅可以坚持，而且可以茁壮成长。尽管游泳速度可能不是确定所有污染物影响的合适指标，但我们对耐受性的最佳和亚致死效应的关注允许选择与物种生理特征相匹配的最合适的重新引入位点。