Seaver, G.A. and Kuzirian, A.M., 2024. Estuary nitrate sources and trends in Buzzards Bay. Journal of Coastal Research, 40(6), 1055–1067. Charlotte (North Carolina), ISSN 0749-0208.

The determination of estuary nitrate sources originating through groundwater was the principal objective of this work. This required long timeline (35-year) measurements over many seasonal cycles. Typically, in this study, nitrate sources were an upgradient from estuaries at a significant distance, usually greater than 300 m (1000 ft), whereas groundwater flow that transported the nitrate near the coast in Buzzards Bay, Massachusetts, traveled only 0.45 m/d (1.5 ft/d). Thus, it takes years before a potential newly discovered nitrate source could be confirmed in the estuary. Investigation of estuary nitrate trends and the significance of obtaining winter nitrate measurements to investigations was more fully developed in this work. This showed that determining the estuarian nitrate trends also required a timeline much longer than the variability of the nitrate influx into the estuary. The large, summer-to-winter high nitrate (but not low nitrate) differences and the system's inherent physiological ecology were central to regulating nitrate in an estuary, despite greatly increased groundwater nitrate input. The winter measurement data explained this phenomenon. Finally, the data measurement program completed in Buzzards Bay proved to be ideal in answering these necessarily long timeline questions. The research suggested a new parameter be used to indicate an excess nitrate state of an estuary. These long-term data also allowed meaningful calculations of estuarine and groundwater nitrate and temperature trends.