Glibert, P. M. University of Maryland Center for Environmental Science, Glibert@hpl.umces.edu
Terlizzi, D. M. University of Maryland Sea Grant, dt37@umail.umd.edu
Lomas, M. W. University of Maryland Center for Environmental Science, lomas@hpl.umces.edu
Fan, C. University of Maryland Center for Environmental Science,

 
CO-OCCURRENCE OF DINOFLAGELLATE BLOOMS AND ELEVATED LEVELS OF UREA UNDER HIGHLY EUTROPHIC CONDITIONS
 
Links between the growth of harmful algal blooms and nutrient loading have often been made, but the physiological mechanisms by which dinoflagellates, such as Gyrodinium, Prorocentrum, or Gymnodinium respond to environmental nutritional conditions is uncertain. We studied the relationships between inorganic and organic nitrogen and the growth of dinoflagellates in eutrophic conditions and we have found a striking relationship between the availability and uptake of urea and the outbreak of dinoflagellates. In 25 sampling periods in estuarine ponds, spanning a temperature range of 5-30C, urea concentrations >1.5 uM (n=13) co-occurred with dinoflagellates 75% of the time, whereas urea concentrations <1.5 uM (n=12) did not correlate with dinoflagellate blooms. No relationships were noted between dinoflagellate blooms and the concentrations of either ammonium or nitrate. The uptake of urea may be favored under highly eutrophic or dense bloom conditions.
 
Day: Friday, Feb. 5
Time: 04:15 - 04:30pm
Location: Eldorado Hotel
 
Code: SS42FR0415E