Table 1. Environmental conditions and nifH RT-qPCR results at Cape Verde sampling stations.
| Sample | Station | Lat. (°N) | Long. (°W) | Date (dd.mm.yy) | Time (hh:mm) | Temp ( °C) | Salinity (Psu) | BNF rate (nmolN l−1 h−1) | Nitrate+ nitrite (μ) | PO43− (μ) | Iron (n) | Chl a (μg l−1) | nifH transcripts per l |
||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UCYN-A | UCYN-B | Tricho. | RR | HR | γ-prot | α-prot | |||||||||||||
| 1 | A | 17.72 | −22.74 | 17.11.07 | 4:09 | 24.9 | 36.8 | 6.3 | <0.02 | 0.05 | 1.51 | 0.1 | 1.3E+05 | DNQ | UD | 8.8E+02 | UD | UD | UD |
| 2 | B | 16.89 | −24.83 | 22.11.07 | 4:34 | 25.3 | 36.7 | 6.0 | 0.05 | 0.09 | 0.58 | 0.33 | 1.0E+04 | UD | 4.9E+03 | UD | UD | UD | UD |
| 3 | B | 16.89 | −24.83 | 22.11.07 | 13:53 | 25.2 | 36.8 | 6.0 | 0.06 | 0.10 | 0.38 | 1.4E+03 | UD | UD | DNQ | DNQ | DNQ | UD | |
| 4* | B | 16.89 | −24.83 | 22.11.07 | 13:53 | 25.2 | 36.8 | 6.0 | 4.12 | 0.33 | 1.9E+03 | DNQ | 5.2E+02 | UD | 2.2E+03 | UD | UD | ||
| 5 | C | 16.01 | −23.66 | 28.11.07 | 6:50 | 24.9 | 36.8 | 0.5 | 0.12 | 0.06 | 0.32 | 0.19 | UD | UD | 6.3E+02 | DNQ | 8.6E+02 | UD | UD |
| 6 | C | 16.02 | −23.73 | 28.11.07 | 6:45 | 24.7 | 36.5 | 0.1 | 0.06 | 0.06 | 0.22 | UD | UD | 9.0E+02 | DNQ | 1.1E+03 | UD | UD | |
| 7 | C | 16.02 | −23.74 | 28.11.07 | 10:15 | 24.7 | 36.5 | 0.3 | 0.06 | 0.06 | 0.32 | UD | UD | 2.5E+03 | DNQ | 1.0E+03 | UD | UD | |
| 8 | C | 16.03 | −23.76 | 28.11.07 | 14:10 | 24.7 | 36.4 | 0.4 | 0.053 | 0.04 | UD | UD | UD | UD | ND | UD | UD | ||
| 9 | C | 16.04 | −23.78 | 28.11.07 | 18:15 | 24.7 | 36.5 | 0.5 | 0.053 | 0.04 | UD | UD | DNQ | UD | ND | UD | UD | ||
| 10 | C | 16.03 | −23.78 | 28.11.07 | 23:35 | 24.7 | 36.5 | 0.2 | 0.053 | 0.04 | UD | UD | UD | ND | ND | UD | UD | ||
| 11 | C | 16.02 | −23.77 | 28.11.07 | 2:00 | 24.6 | 36.5 | 0.2 | 0.05 | 0.04 | UD | UD | UD | DNQ | UD | UD | UD | ||
| 12 | D | 17.72 | −22.95 | 02.12.07 | 6:15 | 23.9 | 36.8 | 0.1 | <0.02 | 0.08 | 0.3 | 0.12 | 4.1E+04 | UD | UD | DNQ | ND | DNQ | UD |
| 13 | D | 17.78 | −22.96 | 02.12.07 | 10:10 | 23.9 | 36.8 | 0.3 | <0.02 | 0.12 | 7.3E+04 | 1.5E+03 | DNQ | DNQ | UD | DNQ | UD | ||
| 14 | D | 17.79 | −22.97 | 02.12.07 | 14:15 | 24 | 36.8 | 0.2 | <0.02 | 0.12 | 1.6E+04 | UD | UD | ND | ND | DNQ | UD | ||
| 15 | D | 17.80 | −23.00 | 02.12.07 | 18:15 | 24 | 36.8 | 0.3 | <0.02 | 0.12 | DNQ | UD | UD | DNQ | UD | UD | UD | ||
| 16 | D | 17.81 | −23.05 | 02.12.07 | 23:05 | 24 | 36.9 | 0.2 | <0.02 | 0.12 | 4.5E+03 | UD | UD | DNQ | UD | UD | UD | ||
| 17 | D | 17.81 | −23.09 | 03.12.07 | 2:30 | 23.9 | 36.9 | 0.1 | <0.02 | 0.14 | DNQ | UD | UD | 1.0E+03 | UD | UD | UD | ||
| 18 | E | 20.65 | −24.96 | 07.12.07 | 5:30 | 23.9 | 36.9 | 0.1 | <0.02 | 0.06 | 0.35 | 0.08 | 7.6E+04 | UD | DNQ | UD | UD | DNQ | UD |
| 19 | E | 20.85 | −25.01 | 07.12.07 | 6:25 | 23.9 | 37.0 | 0.1 | <0.02 | 0.05 | 4.5E+04 | UD | 9.5E+02 | DNQ | UD | 8.1E+03 | UD | ||
| 21 | E | 20.94 | −25.04 | 07.12.07 | 14:00 | 23.9 | 36.9 | 0.3 | <0.02 | 0.05 | 2.4E+04 | UD | DNQ | UD | UD | DNQ | UD | ||
| 22 | E | 20.98 | −25.05 | 07.12.07 | 18:25 | 23.9 | 36.9 | 0.1 | <0.02 | 0.05 | 3.4E+03 | DNQ | UD | UD | UD | 8.7E+03 | UD | ||
| 23 | E | 21.04 | −25.05 | 07.12.07 | 22:55 | 23.8 | 36.9 | ND | <0.02 | 0.05 | 4.4E+04 | UD | UD | DNQ | UD | DNQ | UD | ||
| 24 | E | 21.08 | −25.05 | 08.12.07 | 1:55 | 23.8 | 36.9 | ND | <0.02 | 0.05 | 1.2E+05 | UD | UD | UD | UD | UD | UD | ||
| 25 | F | 26.05 | −23.99 | 12.12.07 | 6:15 | 23.3 | 37.4 | bdl | <0.02 | <0.02 | 0.54 | 0.06 | DNQ | UD | DNQ | DNQ | ND | DNQ | UD |
| 26 | F | 26.05 | −23.98 | 12.12.07 | 10:15 | 22.7 | 37.3 | 0.1 | <0.02 | <0.02 | DNQ | UD | 1.2E+03 | 1.6E+03 | DNQ | DNQ | UD | ||
| 27 | F | 26.07 | −23.99 | 12.12.07 | 14:15 | 22.9 | 37.3 | 0.1 | <0.02 | <0.02 | UD | DNQ | DNQ | DNQ | DNQ | DNQ | UD | ||
| 28 | F | 26.09 | −24.01 | 12.12.07 | 18:20 | 22.7 | 37.3 | 0.1 | <0.02 | <0.02 | DNQ | 1.4E+03 | DNQ | DNQ | 1.5E+03 | 6.8E+03 | UD | ||
| 29 | F | 26.08 | −24.00 | 12.12.07 | 23:10 | 22.6 | 37.3 | 0.1 | <0.02 | <0.02 | DNQ | UD | UD | 9.5E+02 | DNQ | UD | UD | ||
| 30 | F | 26.10 | −23.99 | 13.12.07 | 2:30 | 22.6 | 37.3 | bdl | <0.02 | <0.02 | 6.8E+02 | UD | DNQ | 3.2E+03 | DNQ | DNQ | UD | ||
Abbreviations: α-prot, α-24809A06; bdl, below detection limit; BNF, biological nitrogen fixation; DNQ, detected not quantified; γ-prot, γ-24774A11; HR, Richelia in Hemiaulus; ND, no data; RR, Richelia in Rhizosolenia; RT-qPCR, quantitative reverse transcription-polymerase chain reaction; UD, undetected.
Sites are divided into Stations A–F, grouped by similar latitude and longitudes. Diel sampling occurred at Stations C–F. All samples were taken within the mix layer, thus considered to be surface or near-surface samples, with the exception of B4 (marked with an asterisk), which was sampled at 50 m.