Aquatic surfaces are frequently impacted by fouling organisms, a challenge that is costly and difficult to manage. While antifouling solutions often focus on preventing attachment or colonization, the physiological impacts of these materials on marine species are less understood. This study explores how common marine infrastructure and natural materials affect the physiology of barnacles. We examine the impacts on barnacle shell and adhesive plaque morphology using microcomputed tomography, highlighting changes in structure that may influence fitness and ability to attach to structures. Additionally, we investigate the physiological responses of fish to the antifoulant irgarol, a widely detected biocide. We assess irgarol’s effects on fish survival, development, cardiac function, mitochondrial bioenergetics, and behavior, and find that fish exposed to concentrations currently detected in the environment have altered heart function and swimming behavior. By focusing on these physiological impacts, this research offers insights into how materials and antifoulants impact aquatic organisms. These findings are critical for developing more sustainable and effective antifouling strategies that minimize harm to non-target organisms while protecting infrastructure vulnerable to fouling organisms.