Impacts of sedimentation on early-life phenotypes and gene expression in coho salmon (Oncorhynchus kisutch)

Lai, Carina M.

Impacts of sedimentation on early-life phenotypes and gene expression in coho salmon (Oncorhynchus kisutch)

dc.contributor.advisor	Rogers, Sean Michael
dc.contributor.author	Lai, Carina M.
dc.contributor.committeemember	Munkittrick, Kelly Roland
dc.contributor.committeemember	Vijayan, Mathilakath
dc.contributor.committeemember	Else, Brent
dc.date	2025-06
dc.date.accessioned	2025-01-09T16:22:51Z
dc.date.available	2025-01-09T16:22:51Z
dc.date.issued	2025-01-03
dc.description.abstract	Early-life environmental stressors may threaten species of conservation concern by impacting populations during vulnerable early life history stages. Here, I tested some of the effects of sediment stress and hypoxia during early-life development on phenotypic outcomes and gene expression in coho salmon (Oncorhynchus kisutch). I obtained O. kisutch eggs from the Sugsaw Hatchery located on Vancouver Island, BC, and reared them in one of three substrate (0% fine sediment, 10% fine sediment, 20% fine sediment) or one of two no substrate (normoxia/100% DO or hypoxia/50% DO) treatments to the alevin stage (n=180 per treatment). Survival did not differ between groups, but fish reared in hypoxia and 20% fine sediment exhibited significantly lower fork lengths and weights. Yolk sac area and volume were also lower in fish from the 20% fine sediment treatment, suggesting a decrease in yolk sac conversion efficiency. Gene expression analysis of three general (HIF1A_6, ALD_1, HemA1_1) and four hypoxia-specific (Anillin, Ncapd3, Ndc80, Kif4) biomarkers revealed significant upregulation of ALD_1 expression in hypoxia-reared fish, while fewer significant differences were detected in the remaining biomarkers. Overall, more research is necessary to elucidate the genomic mechanisms mediating the phenotypic changes that result from exposure to hypoxia and high sedimentation in early-life salmonids. Yet these findings suggest that there may be negative consequences of sedimentation and hypoxia during early-life salmonid development and that these are driven by complex molecular interactions that underlie early-life organisms’ responses to stress. Reduced growth and yolk sac conversion efficiency in fish reared without substrate, compared to high quality substrate further suggest that substrate environmental enrichment (EE) during early-life rearing may be beneficial for salmonids artificially reared in hatcheries.
dc.identifier.citation	Lai, C. M. (2025). Impacts of sedimentation on early-life phenotypes and gene expression in coho salmon (oncorhynchus kisutch) (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	https://hdl.handle.net/1880/120390
dc.language.iso	en
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject.classification	Ecology
dc.subject.classification	Fisheries and Aquaculture
dc.subject.classification	Biology--Molecular
dc.title	Impacts of sedimentation on early-life phenotypes and gene expression in coho salmon (Oncorhynchus kisutch)
dc.type	master thesis
thesis.degree.discipline	Biological Sciences
thesis.degree.grantor	University of Calgary
thesis.degree.name	Master of Science (MSc)
ucalgary.thesis.accesssetbystudent	I do not require a thesis withhold – my thesis will have open access and can be viewed and downloaded publicly as soon as possible.