Thermal discharge and heatwaves under climate change may increase water temperature. In this study, the individual and combined effect of elevated temperature and cadmium (Cd) toxicity on somatic growth and reproduction of Daphnia magna was evaluated using a simplified dynamic energy budget model (DEBtox). The model predicted that the maximum body length (L_m) would be shorter (3.705 mm) at an elevated temperature of 25 °C than at 20 °C (3.974 mm), whereas the maximum reproduction rate (${\dot{R}}_m$) would be higher at 25 °C (5.735) than at 20 °C (5.591). The somatic growth and reproduction of D. magna were significantly (p < 0.05) reduced with increasing Cd concentrations, and the reduction was greater at 25 than at 20 °C. The potentiation effect of elevated temperature on Cd toxicity was correctly simulated by assuming four toxicological modes of action influencing assimilation, somatic maintenance and growth, and reproduction. Overall, the population growth rate of D. magna was expected to decrease linearly with increasing Cd concentrations, and the decrease was expected to be higher at 25 than at 20 °C. These findings suggest a significant ecological risk of toxic metals at elevated temperature, with a mechanistic interpretation of the potentiation effect using a DEBtox modeling approach.

气候变化下的热排放和热浪可能会增加水温。在这项研究中，使用简化的动态能量收支模型 (DEBtox) 评估了高温和镉 (Cd) 毒性对大溞体细胞生长和繁殖的单独和组合影响。该模型预测，在25 °C 的高温下，最大体长 ( L _m ) 将比在 20 °C (3.974 mm) 时更短 (3.705 mm)，而最大繁殖率 (${\dot{\mathrm{电阻}}}_{米}$) 在 25 °C (5.735) 时会高于在 20 °C (5.591) 时。D. magna的体细胞生长和繁殖 随着 Cd 浓度的增加而显着降低（p < 0.05），并且在 25°C 时的减少量大于在 20°C 时的减少量。通过假设影响同化、体细胞维持和生长以及繁殖的四种毒理学作用模式，正确模拟了升高温度对 Cd 毒性的增强作用。总体而言，D. magna的人口增长率预计会随着 Cd 浓度的增加而线性下降，并且预计在 25 °C 下下降幅度高于 20 °C。这些发现表明有毒金属在高温下存在显着的生态风险，并使用 DEBtox 建模方法对增强效应进行了机械解释。