Physical Sciences and Mathematics Commons^™

The Influence Of Eastern Oyster (Crassostrea Virginica) Reef Restoration On Nitrogen Cycling In A Eutrophic Estuary., Michael Hassett

Master's Theses

Oysters (Crassostrea virginica) are functionally extinct in the urbanized Hudson-Raritan estuary (HRE) in New York City, however, oyster restoration is promoted to mitigate nitrogen (N) pollution via oysters' filtration and excretion. Seasonally, I took 12 sediment cores (45 cm2) adjacent to and 10 m away from a recently constructed reef in the HRE. Cores were incubated in flow-through chambers with site water containing (1) no amendments, (2) 15N-ammonium, or (3) 15N-nitrate, from which I calculated coupled nitrification-denitrification and direct denitrification as isotope-enriched N2. Coupled denitrification was minimal at all sites while direct denitrification was elevated near the reef, suggesting organic …