Nitrogen Uptake Rates during Spring in the NE Arabian Sea

Table 3

Station number, euphotic depth-integrated uptake rates (mmol N m⁻² d⁻¹) of nitrate (𝜌NO₃), ammonium (𝜌NH₄), and urea (𝜌NO₃), N₂ fixation rates (𝜌N₂) and f-ratios (f₁ and f₂) data at different sampling stations. Errors associated with the values are 1-sigma standard deviation.

Station No.	𝜌NO3	𝜌NH4	𝜌urea	𝜌N2^a	f1	f2
2	0.55 ± 0.04	0.39 ± 0.01	0.11 ± 0.01	0.54	0.52 ± 0.03	0.69 ± 0.03
4	0.90 ± 0.03	0.23 ± 0.01	0.13 ± 0.01	0.36	0.71 ± 0.02	0.78 ± 0.02
5	1.00 ± 0.02	0.35 ± 0.01	0.15 ± 0.05	0.10	0.67 ± 0.03	0.69 ± 0.03
8	0.94 ± 0.03	0.13 ± 0.02	0.13 ± 0.01	0.008	0.78 ± 0.02	0.78 ± 0.02
10	1.29 ± 0.01	0.19 ± 0.02	0.10 ± 0.01	0.008	0.82 ± 0.02	0.82 ± 0.02
12	0.39 ± 0.01	0.10 ± 0.01	0.08 ± 0.01	0.002	0.68 ± 0.01	0.69 ± 0.01
14	0.56 ± 0.01	0.14 ± 0.02	0.09 ± 0.01	0.08	0.71 ± 0.02	0.74 ± 0.02
15	0.22 ± 0.05	0.07 ± 0.01	0.05 ± 0.01	0.35	0.65 ± 0.08	0.83 ± 0.08

a: N₂ fixation rates = Trichodesmium abundance × 1.5 pmol N trichome⁻¹h⁻¹× 12 h.