Paerl, H. W.. Univ. of North Carolina at Chapel Hill, Instit. of Marine Sciences,, Hans_Paerl@unc.edu
Peierls, B. W.. Univ. of North Carolina at Chapel Hill, Instit. of Marine Sciences, peierls@email.unc.edu
Pinckney, J. L.. Texas A & M Univ., Dept. of Oceanography, pinckney@ocean.tamu.edu
Whitall, D. R.. Univ. of North Carolina at Chapel Hill, Instit. of Marine Sciences, dwhitall@sph.unc.edu

 
ANTHROPOGENICALLY-DERIVED ATMOSPHERIC NITROGEN: ITS POTENTIAL ROLES IN COASTAL EUTROPHICATION
 
Atmospheric deposition of nitrogen (AD-N), much of which arises from man-made emissions (fossil fuel combustion, biomass burning, agricultural practices), is a significant and growing source of "new" N input, which may be implicated in eutrophication of N-limited estuarine and coastal waters. Phytoplankton community structural and functional changes, associated trophic and biogeochemical alterations (i.e., algal blooms, food web alterations, hypoxia) are consequences of eutrophication. In N-limited waters, competition is intense for potentially available N sources. As such, there is substantial individuality among phytoplankton functional groups (i.e., diatoms, dinoflagellates, cyanobacteria, cryptophytes, etc.) in terms of responses to specific inorganic and organic forms of N enrichment found in AD-N. The selective ability of some groups to heterotrophically utilize organic N may also provide a competitive advantage. Quantity and composition of N supply are important community structuring features. When combined with other atmospheric nutrient sources (e.g., Fe), AD-N is a particularly potent stimulant of primary production. Increases in and changing proportions of various new N and other "new" nutrient sources regulate phytoplankton competitive interactions, dominance and successional patterns. These quantitative and qualitative impacts of atmospheric nutrient loading may promote major biotic changes now apparent in these waters, including the proliferation of nuisance bloom species.
 
Day: Thursday, Feb. 4
Time: 08:30 - 08:45am
Location: Sweeney Center
 
Code: SS39TH0830S