Hello MARMAMers, My co-authors and I are excited to share our new publication at Chemosphere: Lemos LS, Silva EM, Steinman KJ, Robeck TR, Quinete NS. 2024. Assessment of per- and poly-fluoroalkyl substances and physiological biomarkers in aquarium-based bottlenose dolphins and killer whales. Chemosphere 364: 143038. DOI: doi.org/10.1016/j.chemosphere.2024.143038. https://www.sciencedirect.com/science/article/pii/S0045653524019337 Abstract: Environmental concerns about per- and polyfluoroalkyl substances (PFAS) are considerably increasing due to their extensive use in commercial and consumer products. PFAS bioaccumulate and biomagnify throughout the food chain, and their toxicity and potential adverse health effects can potentially represent a threat to living organisms. In this study, we described PFAS profiles in the serum of two species of zoo-based bottlenose dolphins (Tursiops truncatus, n = 14 individuals) and killer whales (Orcinus orca, n = 14 individuals) from three locations (California, Florida, and Texas, USA), from 1994 to 2020. Potential physiological effects of PFAS were also explored by measuring different biomarkers (cortisol, corticosterone, aldosterone, TBARS, and hydrogen peroxide) while accounting for individual age, sex, and reproductive stage. All PFAS were detected in at least one of the individuals, considering both species. ΣPFAS reached 496 ng mL−1 in bottlenose dolphins and 230 ng mL−1 in killer whales. In both species, the PFAS with higher mean concentrations were PFOS (108.0–183.0 ng ml−1) and PFNA (14.40–85.50 ng ml−1), which are long-chain compounds. Newborn individuals of both species were also exposed to PFAS, indicating transference via placenta and lactation. Linear mixed model analyses indicated significant correlations between aldosterone, month, year, location, and status; and between hydrogen peroxide, month, year, age, status, ΣPFAS, and Σ short-chain PFAS in killer whales suggesting seasonal variations related to the animal's physiological state (e.g., reproductive cycles, stress responses, weaning events) and increased reactive oxygen species formation due to PFAS exposure. Given our results, other contaminant classes should be investigated in cetaceans as they might have additive and synergistic detrimental effects on these individuals. This study lays the foundation to guide future researchers and highlights the importance of such assessments for animal welfare, and species conservation. Our results may inform management decisions regarding regulations of contaminant thresholds in delphinids. Cheers, [cid:03225ce8-3101-4ee5-8a7f-bc13c9d2310a] Leila S. Lemos, Ph.D. Institute of Environment Florida International University | MMC 11200 SW 8th St, VH 310 & 321 Miami, FL 33199 (971) 3409610​ https://www.researchgate.net/profile/Leila_Lemos https://www.linkedin.com/in/leila-soledade-lemos-94972415/