Abstract
Ocean acidification, driven by the dissolution of approximately 30% of atmospheric carbon dioxide into seawater, poses a significant threat to marine ecosystems. This process, involving the conversion of CO2 into carbonic acid and a subsequent reduction in seawater pH, adversely affects calcifying organisms such as corals by depleting the carbonate ions essential for their skeletal structure. Despite its importance, the spatiotemporal variability of seawater carbonate chemistry in Pacific island coastal regions, including Samoa, remains poorly characterized. To address this knowledge gap, a study was conducted to investigate the variability in seawater carbonate chemistry at five sites along the North coast of Upolu Island, Samoa. The mean pH was measured spectrophotometrically using the m-Cresol purple buffer, and total alkalinity was determined through titration with standardized 0.101970 mol/kg HCl. Measurements were taken at three wavelengths: a non-absorbing wavelength (730 nm for m-Cresol purple) and at the wavelengths corresponding to the absorption maxima of the base (I2–) and acid (HI–) forms of the dye (578 and 434 nm). The EMF values from the seawater titration were used to calculate the actual pH and AT.
Presenters
Tina Taitaifono MarekoClimate Change and Disaster Risk Management Lecturer, Faculty of Science, National University of Samoa, Fa'asaleleaga, Samoa
Details
Presentation Type
Paper Presentation in a Themed Session
Theme
2025 Special Focus—Sustainable Development for a Dynamic Planet: Lessons, Priorities, and Solutions
KEYWORDS
SDG14, CLIMATE CHANGE, OCEAN ACIDIFICATION, IMPACT AND RESPONSES
