Municipal Wastewater Effluent and Stormwater impacts the acute stress-induced Metabolic Rate and Plasma Metabolome in Rainbow Trout
Date
2023-09-22
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Municipal wastewater effluent (MWWE) and urban runoff (stormwater) are complex contaminant mixtures that have the potential to impact aquatic biota including fish. Stormwater consists of compounds such as herbicides, pesticides, nutrients, metals, hydrocarbons, and emerging contaminants that wash off surfaces within urban catchments and into aquatic environments, while MWWE often includes nutrients and pharmaceuticals that can be resistant to current treatment methods. Previous studies have identified obesogenic and reproductive effects on wild fish populations within the Bow River, however the influence of these effects on stress performance, swimming ability, and energy metabolism have received less attention. The objective of this thesis was to use a metabolomic approach to investigate whether metabolic costs associated with MWWE and stormwater exposure altered stress response, swimming ability, and metabolic rate of an economically important sportfish, rainbow trout (Oncorhynchus mykiss), in the Bow River as it flows through Calgary, Alberta. We hypothesized that metabolic costs for detoxification would reduce the ability of rainbow trout to cope with an acute secondary stressor (Chapter 2), and that these costs would also reduce swimming ability and energy availability during a strenuous swim performance test (Chapter 3). Our findings indicate that cortisol release following activation of the hypothalamus-pituitary-interrenal (HPI) axis by an acute 1-min air exposure stressor was maintained following in vivo MWWE and stormwater exposure. Plasma metabolomics analysis identified metabolic disruptions that were amplified during stress response resulting in a distinct plasma metabolome response after exposure to MWWE. Metabolite concentrations and activities of pyruvate kinase and lactate dehydrogenase suggest an increased glycolytic capacity and more reliance on anaerobic metabolism following MWWE and stormwater exposure. The maximum metabolic rate (MMR) measured during a ramp swim velocity test was reduced in fish exposed to MWWE and stormwater, and this contributed to a reduced metabolic scope in fish exposed to MWWE. Our results suggest that metabolic disruption caused by MWWE and stormwater reduces energy availability for energy demanding activities such as predator avoidance and migration.
Description
Keywords
Municipal Wastewater, Metabolic Rate, Stress response, Stormwater, Metabolomics, Rainbow Trout, Swim Performance, Oxygen consumption, HPI Axis, Cortisol
Citation
Young, G. P. M. (2023). Municipal wastewater effluent and stormwater impacts the acute stress-induced metabolic rate and plasma metabolome in rainbow trout (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.