Hexagenia spp. are sensitive indicators of freshwater ecosystem health, as they are highly susceptible to changes in habitat, and nutrient pollution. Because they require clean and well-oxygenated environments for their growth and development, declines in their populations can signal ecological stress and degradation. Their sensitivity to road salt has negatively impacted their population and led to significant changes in their fitness, and physiology, and ultimately it can affect the food web stability in the Great Lakes. In this study, we examined how CaCl2 + Mg affects drift, net-metabolism (ΔO2), toxicity as measured by effective and lethal concentrations (EC50 and LC50), and shifts in feeding strategies (13C and 15N stable isotopes) in Hexagenia. Three groups of experiments were set up encompassing the acute exposure of CaCl2 + Mg (0, 5, 8, and 12 parts per thousand) for 1, 120, and 504 hours under controlled conditions. Lower CaCl2 + Mg exposure led to 15N enrichment, increased dry weight, and enhanced respiration. This suggests that Hexagenia may be adjusting their energy reserves for ion transport and optimizing Ca²⁺ for energy consumption and release in response to varying levels of CaCl2 + Mg. The LC50 was estimated to be between 11.01 and 18.18 ppt, and drifting responses were not statistically linked to CaCl2 + Mg gradients, although their physiology was markedly affected. This study provides critical insights into biological and chemical interactions, as well as the potential impacts on aquatic ecosystems by providing a deeper understanding of how road salt inputs affect sensitive indicators and community dynamics.