Uptake rates of nitrate, ammonium, and urea were measured on
2 September, 2010, when non-bloom and bloom concentrations of
ammonium were 0.52 0.12 and 1.31 0.05 mM respectively,
nitrate concentrations were 1.39 0.31 and 0.40 0.21 mM respectively,
and urea concentrations were 0.38 0.09 and 0.33 0.06 mM
respectively. Nitrogen uptake was more than five-fold faster in the
bloom compared to the adjacent non-bloom water (Fig. 8A).
Ammonium was taken up at seven-fold higher rates by bloom
communities (0.19 0.01 mmol L1 h1 in non-bloom community vs
1.52 0.12 mmol L1 h1) whereas urea and nitrate utilization
rates were only three-fold higher (0.63 0.01 and 0.27
0.02 mmol L1 h1, respectively for bloom, 0.18 0.01 and
0.09 0.01 mmol L1 h1, respectively, for non-bloom communities;
Fig. 8A).