John M. Fear
University of North Carolina at Chapel Hill
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Proceedings of the National Academy of Sciences of the United States of America | 2001
Hans W. Paerl; Jerad D. Bales; Larry W. Ausley; Christopher P. Buzzelli; Larry B. Crowder; Lisa A. Eby; John M. Fear; Malia Go; Benjamin L. Peierls; Tammi L. Richardson; J. Ramus
Three sequential hurricanes, Dennis, Floyd, and Irene, affected coastal North Carolina in September and October 1999. These hurricanes inundated the region with up to 1 m of rainfall, causing 50- to 500-year flooding in the watershed of the Pamlico Sound, the largest lagoonal estuary in the United States and a key West Atlantic fisheries nursery. We investigated the ecosystem-level impacts on and responses of the Sound to the floodwater discharge. Floodwaters displaced three-fourths of the volume of the Sound, depressed salinity by a similar amount, and delivered at least half of the typical annual nitrogen load to this nitrogen-sensitive ecosystem. Organic carbon concentrations in floodwaters entering Pamlico Sound via a major tributary (the Neuse River Estuary) were at least 2-fold higher than concentrations under prefloodwater conditions. A cascading set of physical, chemical, and ecological impacts followed, including strong vertical stratification, bottom water hypoxia, a sustained increase in algal biomass, displacement of many marine organisms, and a rise in fish disease. Because of the Sounds long residence time (≈1 year), we hypothesize that the effects of the short-term nutrient enrichment could prove to be multiannual. A predicted increase in the frequency of hurricane activity over the next few decades may cause longer-term biogeochemical and trophic changes in this and other estuarine and coastal habitats.
Estuaries | 2005
John M. Fear; Suzanne P. Thompson; Thomas E. Gallo; Hans W. Paerl
Denitrification rates along a salinity gradient in the eutrophic Neuse River Estuary, North Carolina, were quantified using membrane inlet mass spectrometry (MIMS) within short-term batch incubations. Denitrification rates within the system were highly variable, ranging from 0 to 275 μmol N m−2 h−1. Intrasite variability increased with salinity, but no significant differences were observed across the salinity gradient. Denitrification rates were positively correlated with sediment oxygen demand at the upstream sampling site where sediment organic carbon levels were lowest. This relationship was not observed in the more saline sampling sites. Denitrification rates were highest during winter. On an annual basis, denitrification accounted for 26% of the dissolved inorganic nitrogen and 12% of the total nitrogen supplied to the system.
Estuaries and Coasts | 2007
John M. Fear; Hans W. Paerl; Jeremy S. Braddy
Seepage rate and chemical composition of groundwater discharge entering the Neuse River Estuary (NRE) were quantified over an annual cycle from July 2005 through June 2006. Lee type seepage meters were deployed at eight locations within the NRE to quantify the amount of submerged groundwater discharge (SGD) entering the system. Sediment porewater nitrate (NO3−), ammonium (NH4+), and phosphate (PO4−3) were also quantified at each of these locations to determine groundwater chemical composition. Seepage rates for the system ranged from 0.004 to 0.035 m3 m−2 d−1. Both the average and median value for the system-wide SGD were 0.01 m3 m−2d−1. There were no significant differences between upstream and downstream seepage rates or between those at the north and south side of the estuary. Seepage rates varied greatly in time and space. Discharging groundwater was NO3− deplete but highly enriched in NH4+. Porewater PO4−3 levels varied but were usually present below Redfield values due to NH4+ enrichment. SGD nutrient loading represented a small part of watershed nitrogen and phosphorus loading, 0.8% and 1.0%, respectively.
Marine Ecology Progress Series | 1998
Hans W. Paerl; James L. Pinckney; John M. Fear; Benjamin L. Peierls
Estuarine Coastal and Shelf Science | 2004
John M. Fear; Tom Gallo; Nathan S. Hall; Josh Loftin; Hans W. Paerl
Marine Ecology Progress Series | 1999
Hans W. Paerl; James L. Pinckney; John M. Fear; Benjamin L. Peierls
Archive | 2002
Christopher P. Buzzelli; Richard A. Luettich; Hans W. Paerl; John M. Fear; Janelle Fleming; Luke Twomey; Benjamin L. Peierls; Erika J. Clesceri; Marc J. Alperin; Christopher S. Martens
Hydrobiologia | 2011
Karen L. Rossignol; Hans W. Paerl; John M. Fear; Jeremy S. Braddy
Archive | 2017
Sarah Spiegler; Rich Bandy; Carolyn A. Currin; Jennifer Dorton; Rebecca Ellin; Paula Farnell; John M. Fear; Elise Gilchrist; David Allen Glenn; Nathan S. Hall; Whitney Jenkins; Tancred Miller; Brandon Puckett; Justin T. Ridge; K. A. Shein
Water Resources Research Institute News of the University of North Carolina | 2002
Michael F. Piehler; Suzanne P. Thompson; Julianne Dyble; Pia H. Moisander; John M. Fear; Hans W. Paerl