Shifts in key physiological processes can confer resistance to chemical pollutants. However these adaptations may come with certain trade-offs such as altered energy metabolic processes as evident in Atlantic killifish (Fundulus heteroclitus) in Virginia's Elizabeth River (ER) that have evolved resistance to polycyclic aromatic hydrocarbons (PAHs). We seek to understand the bioenergetic costs of PAH resistance among subpopulations of Atlantic killifish with differing contamination levels in order to examine how these changes manifest across multiple life stages and how these costs might be exacerbated by additional stressors. Data herein include mitochondrial function of killifish embryos raw and normalized mitochondrial function data for juvenile killifish whole animal respirometry from juvenile killifish and locomotion for larval killifish.