Oral Presentation Society for Freshwater Science 2025 Annual Meeting

Temperature-dependent PFAS effects on metabolism and swim performance in sheepshead minnows (117820)

Maria Rodgers 1 , Anika Agrawal 2 , Jacqueline Baron 2 , Daniel Bolnick 3 , Sylvain De Guise 4 , Milton Levin 4 , Kat Milligan-McClellan 5 , Jessica Brandt 2 , Margot Grimmelpont 2
  1. Department of Biological Sciences, & Center for Marine Sciences and Technology, North Carolina State University, Morehead City, North Carolina, United States
  2. Department of Natural Resources and the Environment, University of Connecticut, Storrs, Connecticut, United States
  3. Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, United States
  4. Department of Pathobiology and Veterinary Sciences, University of Connecticut, Storrs, Connecticut, United States
  5. Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous environmental contaminants of global concern. These chemicals bioaccumulate in organisms, causing immunotoxic effects, changes in gene expression, and disruptions to ovarian physiology and function. Despite their widespread presence, few studies have investigated how environmental factors, such as temperature, influence PFAS toxicity. Understanding these interactions is essential for improving the environmental risk assessment of chemical contaminants in changing ambient conditions. This study assessed the combined effects of warming scenarios and PFAS mixtures on the metabolic and swimming performance of sheepshead minnows (Cyprinodon variegatus). Fish were exposed to a mixture of PFOS and PFOA (target concentration: 100 ng/mL, consistent with the US EPA’s Aquatic Life Criteria for chronic exposures) under three temperature conditions (24°C, 26°C, and 28.5°C). Metabolic variables (SMR – standard metabolic rate, MMR – maximum metabolic rate, AS – aerobic scope) and critical swimming speed (Ucrit) were measured after 28 days of exposure. Results revealed a significant interaction between temperature and PFAS on AS, with fish exposed to PFAS showing lower AS at 28.5°C compared to those in PFAS-free water. This reduction in AS was attributed to a decrease in MMR at 28.5°C (though not statistically significant), while SMR remained unchanged. Ucrit followed a similar trend to AS and MMR but was not statistically significant. As Ucrit is closely linked to aerobic metabolic performance, these findings suggest that energy-demanding compensatory mechanisms induced by the temperature-PFAS interaction may have been prioritized over swimming effort. Impairments to AS, a proxy for individual fitness, could reduce overall fish performance, potentially affecting growth and reproduction. Overall, this study suggests that PFAS-induced impairments to AS may be exacerbated under future climate scenarios, posing a significant threat to the health of ecosystems.