Dear colleagues, We are very pleased to announce the recent publication of our last paper "Metabolomic profiles of the endangered St. Lawrence Estuary beluga population and associations with organohalogen contaminants". The article is available here: https://authors.elsevier.com/c/1aaCEB8cco9t6 Alternatively, please feel free to email me to get a PDF copy. AUTHORS Simond, A.E., Houde, M., Lesage, V., Michaud, R. and Verreault, J. ABSTRACT The endangered beluga (Delphinapterus leucas) population residing in the St. Lawrence Estuary (SLE; Eastern Canada) is declining. The elevated tissue concentrations of a wide range of organohalogen contaminants might play a role in the non-recovery of this whale population. Organohalogens have been reported to impair the reg- ulation ofseveral metabolic products fromcellular reactions in mammals such as amino acids and fatty acids. The objective of this study was to investigate a suite of organohalogens including polychlorinated biphenyls, organ- ochlorine pesticides, short-chain chlorinated paraffins (SCCPs), polybrominated diphenyl ethers, and selected emerging flame retardants in blubber (biopsy) collected from 40 SLE male belugas, and their relationships to skin concentrations oftargetedmetabolites (i.e., 21 amino acids, 22 biogenic amines, 18 fatty acids, and 17 energy metabolites). A cluster analysis based on metabolomic profiles distinguished two main subgroups of belugas in the upper and lower sector of their summer habitat in the SLE. These results indicate that ecological factors such as local prey availability and diet composition played a role in shaping the metabolite profiles of belugas. Moreover, SCCP concentrations in SLE male belugas correlated negatively with those of four unsaturated fatty acids (C16:1ω7, C22:5ω3c1, C22:5ω3c2, and C22:6ω3), and positively with those of acetylornithine (biogenic amine). These findings suggest that biological functions such as lipid metabolism represent potential targets for organohalogens in this population, and further our understanding on potential health risks associated with elevated organohalogen exposure in cetaceans. Our results also underscore the necessity of considering ecolog- ical factors (e.g., diet and habitat use) in metabolomic studies. KEYWORDS Marine mammal; Metabolomic; Halogenated flame retardant; Organochlorine; Short-chain chlorinated paraffin; Lipid metabolism Regards and all the best, ********************************************************************************************** *ANTOINE SIMOND* *Candidat au doctorat | PhD candidate* Département des sciences biologiques | Biological Sciences Department Université du Québec à Montréal | University of Quebec at Montreal C.P. 8888, Succursale Centre-Ville | P.O. Box 8888, Downtown branch Montréal (Québec), Canada, H3C 3P8 | Montreal (Quebec), Canada, H3C 3P8 Bureau SB-3650 | Office SB-3650 Courriel | E-mail: simond.antoine@courrier.uqam.ca ********************************************************************************************** « *We feel fundamentally disconnected from nature and therefore not responsible for the ecological consequences of our actions. Once we learn that our very being, essence, health and happiness depend on Mother Earth, we have no choice but to radically shift the way we treat her.* » - David Suzuki.