The independent and interactive effects of dissolved organic carbon (DOC), major salt ions (Naâº, Ca²âº) or Cu and pH on osmoregulatory processes of the fish gill
department or school: Science, Faculty of
department or school: Zoology, Department of
data provider: DSpace
degree campus: UBCV
creator: Morris, Carolyn
issued: 2025-11-05T18:58:52Z
issued: 2025
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: The ecological roles of dissolved organic carbon (DOC) in aquatic ecosystems are widespread although not yet fully understood, but DOC is likely to impact physiological processes in fish. Generally, DOC is supportive to ionoregulation in freshwater fish, especially in acidic or metal contaminated waters, although the exact protective mechanisms and the influence of water chemistry remain unknown. DOCs can be characterized by optical and chemical indices but the effect of pH and their inter-relationships are not well understood. I showed that the indices used to characterize DOC should consider pH and be interpreted carefully as some changes reflect alterations in conformation (i.e. spatial arrangement of the molecule) while others reflect changes in composition (i.e. chemical makeup of the molecule) resulting from proton binding. I also investigated the independent and interactive effects of DOC and pH, major ion concentrations (Naâº, Ca²âº) and/or a potential metal pollutant (copper, Cu) on fish. To explore the physiological effects of these environmentally relevant DOC-water quality interactions, fish native to specific habitats with different ionoregulatory strategies were utilized: rainbow trout, Pacific sanddab and rock sole, and the Amazonian dwarf cichlid. There were independent effects of major ions (Naâº and Ca²âº), and Cu as well as interactive effects with DOCs which were altered by a change in pH. Generally, DOC was supportive to ionoregulation against physiological disturbances caused by ambient pH, major ions or copper. The pH-dependent physiological responses to DOC may be due to conformation changes in DOC such as condensation or the titration of the negative net charge on both DOC and the gill leading to more interaction. Natural DOC sources spanning a wide variety of characteristics, together with model compounds of known chemistry representing key chemical moieties of natural DOCs, were used. I demonstrated that specific chemical groups of the D…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/92856
note: The independent and interactive effects of dissolved organic carbon (DOC), major salt ions (Na+, Ca2+) or Cu and pH on osmoregulatory processes of the fish gill by Carolyn Morris BSc, Memorial University of Newfoundland, 2012 MSc, McMaster University, 2020 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Zoology) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) October 2025 © Carolyn Morris, 2025 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: The independent and interactive effects of dissolved organic carbon (DOC), major salt ions (Na+, Ca2+) or Cu and pH on osmoregulatory processes of the fish gill Submitted by Carolyn Morris in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Zoology Examining Committee: Chris Wood, Adjunct Professor, Zoology, UBC Supervisor Colin Brauner, Professor, Zoology, UBC Co-supervisor Ora Johannsson, Adjunct Professor, Zoology, UBC Supervisory Committee Member Philip Matthews, Associate professor, Department of Zoology, UBC University Examiner Suzie Currie, Vice-Principal and Associate Vice-President, Research and Innovation, UBC University Examiner Claude Fortin, Professor, Centre eau terre environnement, Institut national de la recherche scientifique, External Examiner Additional Supervisory Committee Members: Patricia Schulte, Professor, Zoology, UBC Supervisory Committee Member iii Abstract The ecological roles of dissolved organic carbon (DOC) in aquatic ecosystems are widespread although not yet fully understood, but DOC is likely to impact physiological processes in fish. Generally, DOC is supportive to ionoregulation in freshwater fish, especially in acidic or metal contaminated waters, although the exact protective mechanisms and the influence of water chemistry remain unknown.…
has type: Thesis/Dissertation
date issued: 2026-05
is shown at: 10.14288/1.0450686
language: eng
degree discipline: Zoology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Wood, Chris M.
contributor: Brauner, Colin J.
type: Text
identifier URI: http://hdl.handle.net/2429/92856