Phosphate Groove: Unlocking the Rhythms of Sedimentary Deposits in the Kickamuit and Taunton Rivers
Education Level
Undergraduate
Faculty Advisor(s)
Professor Stephen O'Shea
Academic Department(s)
Chemistry
Symposium Date
2024
Abstract
Phosphorus can be found in many different forms (organic and inorganic), in soils, water bodies, and ocean sediments (Franson and Jones, 2007). All living organism utilizes phosphorus in numerous metabolic cycles and as structural motifs (Downing et al. 2000). The bioavailability of phosphorus, a limiting nutrient in the environment determines the successful growth of organisms, having a significant impact on primary production, species distribution, and ecosystem structure (Ferrier-Pages et al., 2016). Freshwater deposition of free phosphorus ions occurs upon mixing with alkaline saline waters into marine sediments thus becoming a reservoir for loose and tightly bound forms that can be ecologically recycled within this niche.
In this investigation, the concentration of total phosphate, inorganic phosphate, organic phosphate, and water-soluble phosphate was determined from pore waters extracted from Mt. Hope Bay marine core sediments. Surface water, filtered pore water samples, as well as extruded dried sediment segmented samples were analyzed for their salinity, pH, conductivity, nitrate, nitrite, and sulfate, via HACH® protocols. Elemental analysis by ICP and XRF spectroscopy were conducted following established methods. This study shows that as total organic sediment carbon increases, total phosphate content increases. Pore water-soluble phosphate increases with depth from the surface of the core. No relationship was determined for the ratio of bond inorganic phosphorus to iron, remaining relatively constant with the analysis. The pH of pore water becomes more alkaline with an increase in depth from the surface. This is also reflected in the change observed in nitrate and nitrite content going from an aerobic to an anoxic environment with increasing depth.
Recommended Citation
Wade, Gabriella; Foley, Brennan; Wells, Jamie; Fabrizi, Gabriella; and O'Shea, Stephen, "Phosphate Groove: Unlocking the Rhythms of Sedimentary Deposits in the Kickamuit and Taunton Rivers" (2024). Student Research Symposium. 4.
https://docs.rwu.edu/studentresearchsymposium/4
Comments
This research was presented at the 2024 Rhode Island Summer Undergraduate Research Symposium, held on Friday, July 26, at the University of Rhode Island and supported by RI NSF EPSCoR.