title: Home alone-The effects of isolation on uptake of a pharmaceutical contaminant in a social fish.
abstract: A wide range of biologically active pharmaceutical residues is present in aquatic systems worldwide. As uptake potential and the risk of effects in aquatic wildlife are directly coupled, the aim of this study was to investigate the relationships between stress by isolation, uptake and effects of the psychiatric pharmaceutical oxazepam in fish. To do this, we measured cortisol levels, behavioral stress responses, and oxazepam uptake under different stress and social conditions, in juvenile perch (Perca fluviatilis) that were either exposed (1.03μgl-1) or not exposed to oxazepam. We found single exposed individuals to take up more oxazepam than individuals exposed in groups, likely as a result of stress caused by isolation. Furthermore, the bioconcentration factor (BCF) was significantly negatively correlated with fish weight in both social treatments. We found no effect of oxazepam exposure on body cortisol concentration or behavioral stress response. Most laboratory experiments, including standardized bioconcentration assays, are designed to minimize stress for the test organisms, however wild animals experience stress naturally. Hence, differences in stress levels between laboratory and natural environments can be one of the reasons why predictions from artificial laboratory experiments largely underestimate uptake of oxazepam, and other pharmaceuticals, in the wild.
authors.affiliation: Department of Ecology and Environmental Science, Umeå University, Sweden; Department of Chemistry, Umeå University, Sweden. Electronic address: martina_heynen@web.de.
authors.forename: Martina
authors.initials: M
authors.lastname: Heynen
authors.affiliation: Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden.
authors.forename: Tobias
authors.initials: T
authors.lastname: Backström
authors.affiliation: Department of Chemistry, Umeå University, Sweden.
authors.forename: Jerker
authors.initials: J
authors.lastname: Fick
authors.affiliation: Department of Ecology and Environmental Science, Umeå University, Sweden.
authors.forename: Micael
authors.initials: M
authors.lastname: Jonsson
authors.affiliation: Department of Ecology and Environmental Science, Umeå University, Sweden.
authors.forename: Jonatan
authors.initials: J
authors.lastname: Klaminder
authors.affiliation: Department of Ecology and Environmental Science, Umeå University, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Brodin
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D015415:Biomarkers / Q000378:metabolism; D001822:Body Burden; D006854:Hydrocortisone / Q000378:metabolism; D010076:Oxazepam / Q000493:pharmacokinetics* / Q000633:toxicity; D010471:Perches / Q000378:metabolism*; D012934:Social Isolation; D013315:Stress, Psychological / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics* / Q000633:toxicity
chemical_list: D015415:Biomarkers; D014874:Water Pollutants, Chemical; D010076:Oxazepam; D006854:Hydrocortisone
keywords: Bioconcentration; Brain concentration; Isolation; Pharmaceutical pollution; Shoaling; Stress mediated uptake