title: A multi-level biological approach to evaluate impacts of a major municipal effluent in wild St. Lawrence River yellow perch (Perca flavescens).
abstract: The development of integrated ecotoxicological approaches is of great interest in the investigation of global concerns such as impacts of municipal wastewater effluents on aquatic ecosystems. The objective of this study was to investigate the effects of a major wastewater municipal effluent on fish using a multi-level biological approach, from gene transcription and enzyme activities to histological changes. Yellow perch (Perca flavescens) were selected based on their wide distribution, their commercial and recreational importance, and the availability of a customized microarray. Yellow perch were sampled upstream of a major municipal wastewater treatment plant (WWTP) and 4 km and 10 km downstream from its point of discharge in the St. Lawrence River (Quebec, Canada). Concentrations of perfluoroalkyl substances (PFASs), polybrominated diphenyl ethers (PBDEs) and metals/trace elements in whole body homogenates were comparable to those from other industrialized regions of the world. Genomic results indicated that the transcription level of 177 genes was significantly different (p<0.024) between exposed and non-exposed fish. Among these genes, 38 were found to be differentially transcribed at both downstream sites. Impacted genes were associated with biological processes and molecular functions such as immunity, detoxification, lipid metabolism/energy homeostasis (e.g., peroxisome proliferation), and retinol metabolism suggesting impact of WWTP on these systems. Moreover, antioxidant enzyme activities were more elevated in perch collected at the 4 km site. Biomarkers of lipid metabolism, biosynthetic activity, and aerobic capacities were significantly lower (p<0.05) in fish residing near the outfall of the effluent. Histological examination of the liver indicated no differences between sites. Correlations between PFAS, PBDE, and metal/trace element tissue concentrations and markers of peroxisomal proliferation, oxidative stress, and retinoid metabolism were found at the gene and cellular levels. Present results suggest that relating transcriptomic analyses to phenotypic responses is important to better understand impacts of environmental contamination on wild fish populations.
authors.affiliation: Centre Saint-Laurent, Environment Canada, 105 McGill Street, Montreal, QC H2Y 2E7, Canada. Electronic address: magali.houde@ec.gc.ca.
authors.forename: Magali
authors.initials: M
authors.lastname: Houde
authors.affiliation: Centre Saint-Laurent, Environment Canada, 105 McGill Street, Montreal, QC H2Y 2E7, Canada. Electronic address: maeva.giraudo@ec.gc.ca.
authors.forename: Maeva
authors.initials: M
authors.lastname: Giraudo
authors.affiliation: Centre Saint-Laurent, Environment Canada, 105 McGill Street, Montreal, QC H2Y 2E7, Canada. Electronic address: melanie.douville@ec.gc.ca.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Douville
authors.affiliation: Institut de biologie intégrative et des systèmes, Université Laval, 1030, avenue de la Médecine, Québec, QC G1V 0A6, Canada; Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC G1K 9A9, Canada. Electronic address: berenice.bougas.1@ulaval.ca.
authors.forename: Bérénice
authors.initials: B
authors.lastname: Bougas
authors.affiliation: Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490 de la Couronne, Québec, QC G1K 9A9, Canada. Electronic address: patrice.couture@ete.inrs.ca.
authors.forename: Patrice
authors.initials: P
authors.lastname: Couture
authors.affiliation: Canada Centre for Inland Waters, Environment Canada, 867 Lakeshore Road, P.O. Box 5050, Burlington, ON L7R 4A6, Canada. Electronic address: amila.desilva@ec.gc.ca.
authors.forename: Amila O
authors.initials: AO
authors.lastname: De Silva
authors.affiliation: Canada Centre for Inland Waters, Environment Canada, 867 Lakeshore Road, P.O. Box 5050, Burlington, ON L7R 4A6, Canada. Electronic address: christine.spencer@ec.gc.ca.
authors.forename: Christine
authors.initials: C
authors.lastname: Spencer
authors.affiliation: Centre québécois sur la santé des animaux sauvages, Université de Montréal, C.P. 5000, St-Hyacinthe, QC J2S 7C6, Canada. Electronic address: stephane.lair@umontreal.ca.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lair
authors.affiliation: Centre de recherche en toxicologie de l'environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-ville, Montreal, QC H3C 3P8, Canada. Electronic address: verreault.jonathan@uqam.ca.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Verreault
authors.affiliation: Institut de biologie intégrative et des systèmes, Université Laval, 1030, avenue de la Médecine, Québec, QC G1V 0A6, Canada. Electronic address: louis.bernatchez@bio.ulaval.ca.
authors.forename: Louis
authors.initials: L
authors.lastname: Bernatchez
authors.affiliation: Centre Saint-Laurent, Environment Canada, 105 McGill Street, Montreal, QC H2Y 2E7, Canada. Electronic address: christian.gagnon@ec.gc.ca.
authors.forename: Christian
authors.initials: C
authors.lastname: Gagnon
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002170:Canada; D004784:Environmental Monitoring / Q000379:methods*; D010471:Perches / Q000502:physiology*; D062065:Wastewater / Q000737:chemistry / Q000706:statistics & numerical data; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Biomarkers; Gene transcription; Metals; Municipal wastewater effluent; Organic contaminants; Yellow perch