Table 2. Summary of % contribution of microbial methanol uptake to bacterial carbon production.
| Cruise/date | Zonea | Surface Chl a (mg m−3) | Methanol uptake Σ1%b (ng C m−2 d−1) | Bacterial leucine incorporation (pmol Leu L−1 d−1) | Bacterial carbon productionc Σ1% (ng C m−2 d−1) s-CF Min-CF Max-CF | Methanol % contribution to Bacterial carbon production | ||
|---|---|---|---|---|---|---|---|---|
| Mauritania filament | ||||||||
| 21 April 09 | U | 6.2 | 2.6 | 1760±578 (626–2217) | 44.4 | 42.5 | 94.2 | 3–6 |
| 23 April 09 | U | 3.9 | 1.3 | 1358±645 (190–1870) | 35.0 | 33.6 | 74.3 | 2–4 |
| 24 April 09 | U | 3.9 | 0.93 | 1488±361 (1101–2087) | 36.2 | 34.8 | 77.0 | 1–3 |
| 26 April 09 | U | 3.0 | 0.97 | 1817±503 (913–2279) | 51.3 | 49.2 | 109 | 1–2 |
| 27 April 09 | U | 3.2 | 1442±472d | |||||
| 28 April 09 | U | 1.1 | 1228±612d | |||||
| 29 April 09 | U | 1.2 | 1.2 | 1217±405 | 42.8 | 41.0 | 90.9 | 1–3 |
| 30 April 09 | U | 0.86 | 1.6 | 1504±393 | 55.8 | 53.5 | 119 | 1–3 |
| Atlantic transect | ||||||||
| 17 October 09 | NT | 0.31 | 0.19 | 289±74 (182–341) | 13.3 | 1.82 | 28.2 | 1–10 |
| 18 October 09 | NT | 0.16 | 0.09 | 117±63 (34–183) | 4.01 | 0.55 | 8.53 | 1–9 |
| 20 October 09 | NG | 0.06 | 0.17 | 261±42 (207–295) | 10.4 | 1.44 | 22.3 | 1–17 |
| 22 October 09 | NG | 0.08 | 0.19 | 159±30 (124–197) | 7.65 | 1.05 | 16.3 | 1–19 |
| 23 October 09 | NG | 0.07 | 0.27 | 611±589 (216–1488) | 59.6 | 8.17 | 127 | 0.2–3 |
| 03 November 09 | EqU | 0.14 | 0.18 | 487±137 (307–635) | 14.4 | 1.96 | 30.5 | 1–9 |
| 06 November 09 | EqU | 0.14 | 0.27 | 294±168 (135–445) | 17.3 | 2.37 | 36.8 | 1–13 |
| 09 November 09 | SG | 0.08 | 0.19 | 249±28 (220–283) | 17.0 | 2.33 | 36.1 | 1–10 |
| 10 November 09 | SG | 0.10 | 0.24 | 1188 ±1364 (324–3217) | 111 | 15.1 | 235 | 0.1–2 |
| 11 November 09 | SG | 0.04 | 0.19 | 536±319 (256–995) | 57.3 | 7.85 | 122 | 0.2–2 |
| 15 November 09 | SG | 0.03 | 0.07 | 128±68 (21–187) | 13.4 | 1.84 | 28.4 | 0.3–4 |
U, Mauritanian upwelling; NT, north east temperate Atlantic; NG, North Atlantic gyre; EqU, Equatoral upwelling; SG, southern gyre.
Missing data due to incomplete depth profile, for Atlantic transect dark incubation data shown to compare with upwelling filament.
Integrated (to 1% PAR) bacterial production has been calculated three ways: Max-CF using the theoretical leucine to carbon conversion factor of 1.55 kg C mol leu−1 (Simon and Azam, 1989; Hoppe et al., 2002), which is also the maximum conversion factor found, Min-CF is the lowest. empirical conversion factor found in the literature matched to season and place where possible, 0.7 kg C mol leu−1 has been applied to Mauritanian upwelling waters and 0.1 kgC mol leu−1 has been applied to low chlorophyll a Atlantic transect samples (Alonso-Sáez et al., 2007) s-CF using a conversion factor of 0.73 kg C mol leu−1 applied to all the samples (Morán et al., 2002, 2004; Dixon, 2008; Calvo-Díaz and Morán, 2009; Dixon et al., 2011b).
Only two depths sampled in the top 1–97% PAR depths therefore only average±1 s.d. shown.