The effects of ocean acidification on predator-prey interactions in echinoderms
The need to understand future changes in marine ecosystems has become critically important as increasing atmospheric carbon dioxide (CO₂) drives rapid ocean acidification (OA). OA may improve or reduce the performance of marine species, and the relative impacts on interacting species will largely de...
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ftunivbritcolcir:oai:circle.library.ubc.ca:2429/52799 2023-05-15T17:49:57+02:00 The effects of ocean acidification on predator-prey interactions in echinoderms Vaughan, Megan Lillian Hatfield 2015 http://hdl.handle.net/2429/52799 eng eng University of British Columbia Attribution-NonCommercial-NoDerivs 2.5 Canada http://creativecommons.org/licenses/by-nc-nd/2.5/ca/ CC-BY-NC-ND Text Thesis/Dissertation 2015 ftunivbritcolcir 2019-10-15T18:16:34Z The need to understand future changes in marine ecosystems has become critically important as increasing atmospheric carbon dioxide (CO₂) drives rapid ocean acidification (OA). OA may improve or reduce the performance of marine species, and the relative impacts on interacting species will largely determine changes at the community level. The goal of this thesis was to determine the effects of acidification on predator-prey interactions between red sea urchins (Strongylocentrotus franciscanus) and sunflower stars (Pycnopodia helianthoides), a key predator-prey pair in Northeast Pacific kelp forest ecosystems. I tested this question using laboratory mesocosm experiments. Sea urchins were acclimated to ambient (pCO₂ ~ 500 μatm, pH ~ 8.0) or acidified (pCO₂ ~ 1000 μatm, pH ~ 7.7) conditions, with or without a caged sea star, for 22 weeks in a recirculating seawater system. In Chapter 2, I investigated the effects of OA on the growth, calcification, and feeding rate of P. helianthoides. High CO₂ had a significant positive effect on sea star growth, but no effect on calcified tissue mass. In addition, the consumption rate of turban snails (Chlorostoma funebralis) by sea stars was significantly higher in the high CO₂ treatment. In Chapter 3, I examined the effects of OA on the responses of S. franciscanus to sea star cues. Predator presence and high CO₂ negatively and additively affected sea urchin growth rates, but did not affect alarm responses to predator cues. Significantly higher grazing rates on kelp (Macrocystis pyrifera) were also observed in the presence of predators. Predators, but not CO₂, had a significant negative effect on urchin calcified mass. Urchin spine length was also significantly reduced under acidified conditions. Overall, these findings suggest P. helianthoides responds positively to ocean acidification, but S. franciscanus may suffer reduced fitness at seawater pCO₂ levels predicted for the end of the century. Differential effects of ocean acidification on this predator-prey pair could increase the strength of the trophic interaction and lead to stronger top-down control in the future. Science, Faculty of Zoology, Department of Graduate Thesis Ocean acidification University of British Columbia: cIRcle - UBC's Information Repository Pacific |
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University of British Columbia: cIRcle - UBC's Information Repository |
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ftunivbritcolcir |
language |
English |
description |
The need to understand future changes in marine ecosystems has become critically important as increasing atmospheric carbon dioxide (CO₂) drives rapid ocean acidification (OA). OA may improve or reduce the performance of marine species, and the relative impacts on interacting species will largely determine changes at the community level. The goal of this thesis was to determine the effects of acidification on predator-prey interactions between red sea urchins (Strongylocentrotus franciscanus) and sunflower stars (Pycnopodia helianthoides), a key predator-prey pair in Northeast Pacific kelp forest ecosystems. I tested this question using laboratory mesocosm experiments. Sea urchins were acclimated to ambient (pCO₂ ~ 500 μatm, pH ~ 8.0) or acidified (pCO₂ ~ 1000 μatm, pH ~ 7.7) conditions, with or without a caged sea star, for 22 weeks in a recirculating seawater system. In Chapter 2, I investigated the effects of OA on the growth, calcification, and feeding rate of P. helianthoides. High CO₂ had a significant positive effect on sea star growth, but no effect on calcified tissue mass. In addition, the consumption rate of turban snails (Chlorostoma funebralis) by sea stars was significantly higher in the high CO₂ treatment. In Chapter 3, I examined the effects of OA on the responses of S. franciscanus to sea star cues. Predator presence and high CO₂ negatively and additively affected sea urchin growth rates, but did not affect alarm responses to predator cues. Significantly higher grazing rates on kelp (Macrocystis pyrifera) were also observed in the presence of predators. Predators, but not CO₂, had a significant negative effect on urchin calcified mass. Urchin spine length was also significantly reduced under acidified conditions. Overall, these findings suggest P. helianthoides responds positively to ocean acidification, but S. franciscanus may suffer reduced fitness at seawater pCO₂ levels predicted for the end of the century. Differential effects of ocean acidification on this predator-prey pair could increase the strength of the trophic interaction and lead to stronger top-down control in the future. Science, Faculty of Zoology, Department of Graduate |
format |
Thesis |
author |
Vaughan, Megan Lillian Hatfield |
spellingShingle |
Vaughan, Megan Lillian Hatfield The effects of ocean acidification on predator-prey interactions in echinoderms |
author_facet |
Vaughan, Megan Lillian Hatfield |
author_sort |
Vaughan, Megan Lillian Hatfield |
title |
The effects of ocean acidification on predator-prey interactions in echinoderms |
title_short |
The effects of ocean acidification on predator-prey interactions in echinoderms |
title_full |
The effects of ocean acidification on predator-prey interactions in echinoderms |
title_fullStr |
The effects of ocean acidification on predator-prey interactions in echinoderms |
title_full_unstemmed |
The effects of ocean acidification on predator-prey interactions in echinoderms |
title_sort |
effects of ocean acidification on predator-prey interactions in echinoderms |
publisher |
University of British Columbia |
publishDate |
2015 |
url |
http://hdl.handle.net/2429/52799 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_rights |
Attribution-NonCommercial-NoDerivs 2.5 Canada http://creativecommons.org/licenses/by-nc-nd/2.5/ca/ |
op_rightsnorm |
CC-BY-NC-ND |
_version_ |
1766156482297987072 |