Effects of watershed land use on nitrogen concentrations and δ15 Nitrogen in groundwater
Cole, Marci L.
Kroeger, Kevin D.
McClelland, James W.
MetadataShow full item record
Eutrophication is a major agent of change affecting freshwater, estuarine, and marine systems. It is largely driven by transportation of nitrogen from natural and anthropogenic sources. Research is needed to quantify this nitrogen delivery and to link the delivery to specific land-derived sources. In this study we measured nitrogen concentrations and δ15N values in seepage water entering three freshwater ponds and six estuaries on Cape Cod, Massachusetts and assessed how they varied with different types of land use. Nitrate concentrations and δ15N values in groundwater reflected land use in developed and pristine watersheds. In particular, watersheds with larger populations delivered larger nitrate loads with higher δ15N values to receiving waters. The enriched δ15N values confirmed nitrogen loading model results identifying wastewater contributions from septic tanks as the major N source. Furthermore, it was apparent that N coastal sources had a relatively larger impact on the N loads and isotopic signatures than did inland N sources further upstream in the watersheds. This finding suggests that management priorities could focus on coastal sources as a first course of action. This would require management constraints on a much smaller population.
Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Biogeochemistry 77 (2006): 199-215, doi:10.1007/s10533-005-1036-2.
Showing items related by title, author, creator and subject.
Submarine groundwater discharge to Tampa Bay : nutrient fluxes and biogeochemistry of the coastal aquifer Kroeger, Kevin D.; Swarzenski, Peter W.; Greenwood, Wm. Jason; Reich, Christopher (Elsevier B.V., 2007-01-10)To separately quantify the roles of fresh and saline submarine groundwater discharge (SGD), relative to that of rivers, in transporting nutrients to Tampa Bay, Florida, we used three approaches (Darcy's Law calculations, ...
Geomicrobiology of nitrogen in a coastal aquifer : isotopic and molecular methods to examine nitrification and denitrification in groundwater Rogers, Daniel R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-06)Excess nitrogen input is deleterious to coastal waters, resulting in deterioration of the water quality, increases in harmful algal blooms and disease in commercial fish stocks. A significant portion of this nitrogen ...
Spruill, Timothy B.; Bratton, John F. (2008-01-12)A study was conducted between April 2004 and September 2005 to estimate ground-water and nutrient discharge to the Neuse River estuary in North Carolina. Largest ground-water fluxes were observed to occur generally within ...