Year of Graduation
2021
Level of Access
Restricted Access Thesis
Embargo Period
5-20-2021
Department or Program
Earth and Oceanographic Science
First Advisor
Michéle LaVigne
Abstract
Investigating Gulf of Maine seawater responses to natural and anthropogenic forces is critical because it is one of the fastest-warming bodies of water on Earth. Coastal communities rely on ocean ecosystem services and fisheries, clam, and mollusk flats are at risk due to increasingly stress-inducing conditions. High environmental variability from seasonal fluctuations in temperature, riverine inputs, and primary productivity alongside limited water parameter observations, lead coastal waters to be a major area for research. This project sets out to calibrate the Schiller Coastal Studies Center (SCSC) seawater sensor system with seasonal sampling campaigns. I then calculate the carbonate chemistry and compare laboratory to sensor values to determine sensor limitations. Next, I graph sensor-collected data to visualize pH and pCO2 changes on daily, seasonal, and yearly time scales and finally compare results with Crustose Coralline Algae proxy pH data since ~1920. The data suggest that Harpswell Sound, ME experiences significant variability on all timescales and that calibration significantly reduces pH error. Given that the dynamic environment is influenced on a short scale by extreme tides, day/night cycles, and seasonal changes, some patterns are attributed to processes like primary productivity. Alternatively, long-term interannual to centennial pH variability is complex and may be related to anthropogenic change coupled with fluctuating source currents, increased temperatures, and higher precipitation projections. Such high-frequency data is crucial on local and regional scales because the covariance between rapidly warming waters and climate change, alongside diverse coastal environments, gives rise to short and long-term corrosive seawater conditions.
Restricted
Available only to users on the Bowdoin campus.