Semester of Graduation

Summer 2023

Degree

Master of Science (MS)

Department

Environmental Sciences

Document Type

Thesis

Abstract

I studied the interactive effects of pCO2, temperature, and nutrient limitation on the growth and physiology of the marine coccolithophore, Emiliania huxleyi. This was done to look at the effect of climate change factors on the widespread and abundant calcifying marine organism as a predictor of what the future has to hold. The strain of E. huxleyi (PnB 272 B10) was grown on a 12:12 L:D cycle of illumination and exposed to either high or low pCO2 under nutrient-replete or nitrate-limited conditions across a temperature range of 10–28C. I examined the direct and interactive effects of temperature, pCO2, and nutrient limitation on growth rate, the efficiency of growth, organic carbon production, and calcite saturation state. The results showed that growth rates and growth efficiencies were higher at high pCO2 than at low pCO2 when temperatures were 15–25C but were little different at suboptimal (10C) and supraoptimal (28C) temperatures. Organic carbon production normalized to Chl a decreased (increased) as temperature increased under nutrient-replete conditions (nitrate-limited conditions). The calcite saturation state increased with temperature, decreased with elevated CO2, and was lower under nitrate-limited conditions than nutrient-saturated conditions. The results showed that growth rates and growth efficiency were higher at high pCO2 compared to low pCO2 and the growth efficiencies were consistently higher under nutrient-replete conditions.

Date

7-6-2023

Committee Chair

Laws, Edward

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Available for download on Wednesday, June 05, 2024

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