Fan, c. University of Maryland center for environmental sciences, cfan@hpl.umces.edu
Lomas, M. University of Maryland center for environmental sciences, lomas@hpl.umces.edu
Haramoto, E. University of Maryland center for environmental sciences, erinh@hpl.umces.edu
Glibert, P. M. University of Maryland center for environmental sciences, glibert@hpl.umces.edu

 
NITROGEN AND CARBON UPTAKE KINETICS OF A PROROCENTRUM MINIMUM BLOOM IN CHESAPEAKE BAY, USA
 
Prorocentrum minimum is a common bloom-forming dinoflagellate in Chesapeake Bay, USA. During May 1998, a massive P.minimum bloom occurred in the Choptank River, a tributary of Chesapeake Bay. At the collection site, surface chlorophyll concentration reached up to 750 g/L during peak bloom periods. We measured the kinetics of nitrogenous substrates ( nitrate, ammonium, urea and amino acids) uptake as a function of substrate concentration and irradiance. Maximal uptake rates during peak biomass were found for ammonium (10.26-35.86 g at-N /L/hr ), followed by urea ( 2.07-6.12 g at-N /L/hr). Low uptake rates were noted for nitrate (0.45-2.24 g at-N /L/hr). Nitrogen uptake rates were not substantially different over the irradiance range measured. The uptake of urea-carbon was also measured using 13C. Rates of urea-carbon uptake differed substantially from those of urea-nitrogen uptake over all irradiances and suggest that not only were reduced forms of nitrogen significant in the nutrition of this bloom, but that urea may have played a role in supplying carbon as well.
 
Day: Friday, Feb. 5
Time: 03:45 - 04:00pm
Location: Eldorado Hotel
 
Code: SS42FR0345E