Date of Award
Open Access Dissertation
Jeffry L. Dudycha
In its fifth report in 2014 the IPCC reinforced the contribution of anthropogenic CO2 to global climate change predicting widespread and significant changes to the global climate over a relatively short time scale. The polar regions, including the Southern Ocean surrounding Antarctica, were identified as ecosystems that may experience the most rapid and severe changes. As the Southern Ocean is one of the coldest and most oceanographically stable regions on earth, the endemic fauna likely have no alternative habitats available for migration. Further compounding the challenge these species will face is the substantial degree of adaptation to the extreme cold and oxygen rich waters that may render these species particularly vulnerable to increasing temperatures and pCO2. The Perciform fishes of the suborder Notothenioidei dominate the fauna of the Southern Ocean. These fish have been relatively well studied under heat stress conditions, but only recently have research efforts begun to discern the potentially compounding effects of the multiple stressors, notably increased temperature and pCO2. This effort set out to analyze the genomic response of these fish to increased water temperature (4°C) and increased pCO2 levels (1000 μatm), and in doing so create a wealth of sequence data to serve as the foundation for future research efforts for three notothenioid species Trematomus bernacchii, Pagothenia borchgrevinki and Trematomus newnesi.
By analyzing changes in gene expression under the multi-stressor condition on the transcriptomic, pathway and gene level, I was able to draw insight into the physiological plasticity and potential adaptability of these fish to changing climate conditions in the Southern Ocean. While all three species demonstrated a widespread and substantial response to the multi-stressor condition, these responses varied in timing, duration, intensity of response, and the biological pathways driving the response. T.bernacchii demonstrated a rapid and robust response that quickly returned to basal levels, P. borchgrevinki exhibited a more moderated response that persisted throughout all time periods, whereas T. newnesi exhibited the least dramatic response of the three. By further dissecting the details of each response I was able to suggest potential strengths and weakness within each species and discuss the potential impact on each species’ long term survivability.
Huth, T. J.(2015). Vulnerable Species in a Changing Climate: The Genomic Response of Antarctic Notothenioid Fishes to Predicted Oceanic Conditions as a Model of Physiological Plasticity and Adaptive Capability. (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/3218