Table 1.

Hydrology and biogeochemistry of the three stations investigated

Station	Depth of sampling (m)	Temperature (°C)	Chl a (mg m-3)	[NH4+] nmol N L−1	[Urea] nmol N L−1	[NO3-] nmol N L−1	PPE (103 cell ml−1)	Prochlorococcus (103 cell mL−1)	Synechococcus (103 cell mL−1)	Total community C fixation (nmol C L− h−1)	Total community NH4+ uptake (nmol N L−1 h−1)	Total community urea uptake (nmol N L−1 h−1)	Total community NO3- uptake (nmol N L−1 h−1)
1	5	23.9	0.07	18	89	<2	0.4 ± 0.1	126.3 ± 12.0	1.1 ± 0.1	20.6 ± 1.7	2.45 ± 0.07	3.32 ± 0.14	0.07 ± 0.01
	125	23.1	0.25	21	109	30	1.3 ± 0.5	53.2 ± 2.9	0.2 ± 0.1	12.1 ± 2.1	0.58 ± 0.13	0.67 ± 0.24	0.13 ± 0.10
2	5	20.4	0.11	<3	72	<2	1.2 ± 0.2	99.4 ± 2.0	2.2 ± 0.0	25.1 ± 3.3	1.30 ± 0.01	2.90 ± 0.25	0.10 ± 0.01
	110	20.4	0.21	5	50	30	1.0 ± 0.2	59.6 ± 0.8	1.4 ± 0.1	25.5 ± 1.6	0.83 ± 0.01	1.26 ± 0.26	0.56 ± 0.04
3	5	13.3	0.71	55	162	191	7.2 ± 2.9	4 .2 ± 0.3	37.2 ± 1.4	109.4 ± 11.8	3.39 ± 0.20	1.56 ± 0.21	2.94 ± 0.54
	47	13.1	0.49	59	165	610	6.9 ± 0.4	2.9 ± 0.0	34.6 ± 1.3	88.9 ± 10.9	4.84 ± 0.70	1.73 ± 0.18	1.23 ± 0.28