Investigating the role of Vibrio aestuarianus in summer mortality of farmed Crassostrea gigas in Baynes Sound, British Columbia
Graduate Marine aquaculture is already vital to global food security and will continue to become more important in the coming years. Crassostrea gigas (Pacific oysters) is the primary oyster species cultivated worldwide. The FAO and IPCC predict that climate change will create uncertainty and challe...
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fttriple:oai:gotriple.eu:13534 2023-05-15T15:57:57+02:00 Investigating the role of Vibrio aestuarianus in summer mortality of farmed Crassostrea gigas in Baynes Sound, British Columbia Khtikian, Natalie Flaherty, Mark 2021-11-24 http://hdl.handle.net/1828/13534 en eng 13534 http://hdl.handle.net/1828/13534 undefined UVic’s Research and Learning Repository envir demo Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2021 fttriple 2023-01-22T18:31:00Z Graduate Marine aquaculture is already vital to global food security and will continue to become more important in the coming years. Crassostrea gigas (Pacific oysters) is the primary oyster species cultivated worldwide. The FAO and IPCC predict that climate change will create uncertainty and challenges for marine aquaculture. Baynes Sound, British Columbia, is a productive region for aquaculture, producing >50% of British Columbia’s total annual bivalve production by live weight and value. Major summer mortality events have been documented in farmed Crassostrea gigas globally since the 1950’s. These events are believed to be caused by a multiplicity of factors including changes induced by anthropogenic climate change. One of the major contributors to summer mortality is the proliferation of Vibrio bacteria, specifically Vibrio aestuarianus, which has been shown to increase in abundance and virulence when seawater temperatures rise. Despite this connection and the economic importance of oyster farming in the region, little is known about the presence of V. aestuarianus in Baynes Sound. Our 17-month study sampled 7 sites in Baynes Sound on 33 occasions from May 2019 to September 2020. We found a positive correlation between seawater temperature and total Vibrio detected in water samples in Baynes Sound, an association that was stronger when the overall temperature regime was warmer. We found no significant correlation between any of the bacterial assays tested and salinity, pH, or Ωarag saturation. We also did not identify a geographic pattern to bacterial abundance or virulence amongst test C. gigas in the field. Understanding that flagellates are the predominant type of microalgae present in Baynes Sound when summer mortality events occur, in lab trials, we found that incorporating V. aestuarianus into marine aggregates with flagellate microalgae caused higher mortality than aggregates with diatoms or planktonic V. aestuarianus. These results were not statistically significant but led us to look at how ... Thesis Crassostrea gigas Unknown Pacific |
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envir demo Khtikian, Natalie Investigating the role of Vibrio aestuarianus in summer mortality of farmed Crassostrea gigas in Baynes Sound, British Columbia |
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Graduate Marine aquaculture is already vital to global food security and will continue to become more important in the coming years. Crassostrea gigas (Pacific oysters) is the primary oyster species cultivated worldwide. The FAO and IPCC predict that climate change will create uncertainty and challenges for marine aquaculture. Baynes Sound, British Columbia, is a productive region for aquaculture, producing >50% of British Columbia’s total annual bivalve production by live weight and value. Major summer mortality events have been documented in farmed Crassostrea gigas globally since the 1950’s. These events are believed to be caused by a multiplicity of factors including changes induced by anthropogenic climate change. One of the major contributors to summer mortality is the proliferation of Vibrio bacteria, specifically Vibrio aestuarianus, which has been shown to increase in abundance and virulence when seawater temperatures rise. Despite this connection and the economic importance of oyster farming in the region, little is known about the presence of V. aestuarianus in Baynes Sound. Our 17-month study sampled 7 sites in Baynes Sound on 33 occasions from May 2019 to September 2020. We found a positive correlation between seawater temperature and total Vibrio detected in water samples in Baynes Sound, an association that was stronger when the overall temperature regime was warmer. We found no significant correlation between any of the bacterial assays tested and salinity, pH, or Ωarag saturation. We also did not identify a geographic pattern to bacterial abundance or virulence amongst test C. gigas in the field. Understanding that flagellates are the predominant type of microalgae present in Baynes Sound when summer mortality events occur, in lab trials, we found that incorporating V. aestuarianus into marine aggregates with flagellate microalgae caused higher mortality than aggregates with diatoms or planktonic V. aestuarianus. These results were not statistically significant but led us to look at how ... |
author2 |
Flaherty, Mark |
format |
Thesis |
author |
Khtikian, Natalie |
author_facet |
Khtikian, Natalie |
author_sort |
Khtikian, Natalie |
title |
Investigating the role of Vibrio aestuarianus in summer mortality of farmed Crassostrea gigas in Baynes Sound, British Columbia |
title_short |
Investigating the role of Vibrio aestuarianus in summer mortality of farmed Crassostrea gigas in Baynes Sound, British Columbia |
title_full |
Investigating the role of Vibrio aestuarianus in summer mortality of farmed Crassostrea gigas in Baynes Sound, British Columbia |
title_fullStr |
Investigating the role of Vibrio aestuarianus in summer mortality of farmed Crassostrea gigas in Baynes Sound, British Columbia |
title_full_unstemmed |
Investigating the role of Vibrio aestuarianus in summer mortality of farmed Crassostrea gigas in Baynes Sound, British Columbia |
title_sort |
investigating the role of vibrio aestuarianus in summer mortality of farmed crassostrea gigas in baynes sound, british columbia |
publishDate |
2021 |
url |
http://hdl.handle.net/1828/13534 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Crassostrea gigas |
genre_facet |
Crassostrea gigas |
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UVic’s Research and Learning Repository |
op_relation |
13534 http://hdl.handle.net/1828/13534 |
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