Harrington, M. B.. University of North Carolina at Chapel Hill, Institute of Marine Sciences, monicahh@email.unc.edu
Richardson, T. L, T. B.. University of North Carolina at Chapel Hill, Institute of Marine Sciences,
Pinckney, J. L.. Texas A&M University, pinckney@ocean.tamu.edu
Paerl, H. W.. University of North Carolina at Chapel Hill, Institute of Marine Sciences, hpaerl@email.unc.edu

 
PHYTOPLANKTON COMMUNITY STRUCTURE AS A FUNCTION OF LIGHT AND NITROGEN FORM IN THE NEUSE RIVER ESTUARY, NORTH CAROLINA
 
The Neuse River Estuary is a chronically nitrogen-limited system that is currently experiencing eutrophication due to increased nitrogen (N) loading in various inorganic and organic forms. Symptoms of eutrophication include algal blooms, altered food webs, hypoxia/anoxia and fish kills. As part of the Neuse River Bloom Project, we are investigating how different forms of N (e.g. nitrate, ammonium, and organic N) and their ratios affect phytoplankton community structure in the Neuse River. We performed simulated in situ incubations of Neuse River water (10 h average daylength, maximum irradiance of 700 umol/m2/s at noon) treated with equimolar additions of nitrate, ammonium, or nitrate plus ammonium. Preliminary results showed no difference in algal group composition, as determined by HPLC photopigment profiles, between these treatments. We are also examining how N forms interact with variations in available light, an especially important regulatory factor in turbid environments like estuaries. Our current experiments combine N treatments with varied light regimes to determine whether light and nitrogen forms interact to alter phytoplankton community structure.
 
Day: Wednesday, Feb. 3
Time: 11:00 - 11:15am
Location: Sweeney Center
 
Code: CS59WE1100S