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http://hdl.handle.net/11375/20526
Title: | Pharmaceuticals, wastewater effluent, and agonistic behaviours in a wild, invasive fish (Neogobius melanostomus) |
Authors: | McCallum, Erin |
Advisor: | Balshine, Sigal |
Department: | Psychology |
Publication Date: | 2016 |
Abstract: | Anthropogenic contaminants in aquatic ecosystems are of widespread concern for ecosystem managers, scientists, and the organisms living in impacted habitats. Certain contaminants, like human pharmaceuticals and personal care products that are found in wastewater effluents, have been shown to have subtle but important effects on the physiology and behaviour of exposed organisms. Ecotoxicologists are therefore increasingly using behavioural endpoints to evaluate the impacts of treated wastewater effluents and pharmaceuticals on aquatic animals. However, few studies have evaluated whether behaviour is altered following exposure to wastewater effluents that wild fish are exposed to in their environments. Moreover, few studies have comprehensively evaluated the impacts of a given pharmaceutical or effluent exposure by testing behaviour over multiple behavioural contexts. In my thesis, I examined the effects of a pharmaceutical commonly reported in the environment, the antidepressant fluoxetine, as well as a complex mixture, wastewater effluent, on the behaviour of an invasive fish species, the round goby (Neogobius melanostomus). I focused on aggressive and social behaviours that are both critical for this species’ survival and reproduction, and also explored these behaviours in the absence of any exposure. I showed that round goby are attracted to conspecifics, but do not preferentially associate with larger versus smaller groups of conspecifics (Chapter 2). Most of the “social” interactions were aggressive in nature, and I further explored aggression, showing that round goby were more aggressive over high quality (enclosed) shelters compared to low quality (open) shelters (Chapter 3). When round goby were exposed to the antidepressant fluoxetine, aggression declined rapidly and in multiple aggressive contexts, but only at concentrations higher than those reported in surface waters (Chapter 4). Intriguingly, fish exposed to wastewater effluent in the laboratory also showed reduced aggression towards a mirror (Chapter 5), but fish exposed to wastewater effluent in the wild showed little evidence of behavioural or physiological change following exposure (Chapter 6). Across experiments, I evaluated the relevance of mirror aggression assays as a surrogate for dyadic aggressive contests, and concluded that mirror aggression assays poorly predicted the outcome of more ecologically relevant paired interactions. Altogether, my findings suggest that adult round goby may be resilient to the exposure conditions I tested. My work further develops behaviour as a tool for investigating the impacts on environmental contaminants on aquatic organisms and broadens the species range used for such studies. |
URI: | http://hdl.handle.net/11375/20526 |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
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McCallum_Erin_S_finalsubmission2016September_PhD.pdf | 14.13 MB | Adobe PDF | View/Open |
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