Table 1.
Prokaryotic and viral parameters determined by flow cytometry during the MOCA cruise sampled in six different water masses north (Northern section), within and east (Eastern section) of the Vema Fracture Zone in the (sub)tropical North Atlantic Ocean.
| Water mass | PA (N × 105 cells mL−1) | VA (N × 105 counts mL−1) | VPR | PHP (nmol leu m−3 d−1) | HNA-LS (%) | HNA-HS (%) | LNA (%) | VirHigh (%) | VirMed (%) | VirLow (%) | N |
|---|---|---|---|---|---|---|---|---|---|---|---|
| NORTHERN SECTION | |||||||||||
| 100 m | 4.07 (0.86) | 87.55 (1.13) | 21.9 (2.4) | 260.80 (76.32) | 32.1 (9.5) | 18.1 (5.7) | 49.8 (7.3) | 10.9 (0.9) | 48.6 (5.0) | 40.4 (5.8) | 4 |
| OMZ | 0.58 (0.18) | 9.63 (0.22) | 16.8 (1.4) | 2.89 (1.26) | 37.6 (3.1) | 8.0 (0.5) | 54.4 (3.4) | 4.5 (0.7) | 51.6 (2.8) | 43.9 (3.4) | 4 |
| AAIW | 0.28 (0.05) | 5.55 (0.04) | 20.3 (2.8) | 0.30 (0.06) | 37.3 (1.7) | 10.2 (1.1) | 52.2 (1.9) | 4.1 (1.1) | 48.5 (3.6) | 47.3 (4.7) | 4 |
| UNADW | 0.13 (0.03) | 4.58 (0.07) | 35.7 (2.6) | 0.12 (0.06) | 36.6 (1.6) | 18.2 (1.8) | 45.2 (0.7) | 4.2 (0.4) | 46.6 (3.4) | 49.2 (3.8) | 4 |
| LNADW | 0.11 (0.01) | 4.19 (0.05) | 38.2 (3.6) | 0.05 (0.04) | 34.2 (1.9) | 21.5 (1.3) | 44.2 (1.4) | 4.1 (0.5) | 44.5 (2.1) | 51.5 (2.4) | 4 |
| AABW | 0.13 (0.01) | 4.71 (0.05) | 37.2 (1.8) | 0.05 (0.03) | 34.8 (1.7) | 20.8 (1.8) | 44.4 (1.2) | 4.7 (0.7) | 44.1 (2.1) | 51.2 (2.7) | 4 |
| VEMA FRACTURE ZONE | |||||||||||
| 100 m | 2.60 (0.58) | 57.60 (0.56) | 22.6 (3.7) | 124.44 (20.34) | 33.1 (1.4) | 16.1 (1.6) | 50.8 (1.5) | 8.7 (0.7) | 52.0 (8.3) | 39.3 (8.8) | 3 |
| OMZ | 0.80 (0.14) | 13.02 (0.24) | 16.7 (3.9) | 3.10 (0.69) | 39.2 (2.4) | 7.9 (0.9) | 52.9 (2.9) | 5.1 (1.5) | 56.2 (7.6) | 38.7 (9.1) | 5 |
| AAIW | 0.38 (0.07) | 7.17 (0.20) | 18.4 (2.0) | 0.50 (0.04) | 40.1 (3.3) | 9.5 (0.9) | 50.4 (4.1) | 4.8 (0.8) | 45.8 (3.8) | 49.4 (3.3) | 3 |
| UNADW | 0.18 (0.01) | 6.43* (0.06) | 35.8* (5.3) | 0.12 (0.02) | 37.8 (1.6) | 15.5 (0.8) | 46.8 (0.8) | 5.2 (0.8) | 57.3* (8.5) | 37.5* (9.0) | 3 |
| LNADW | 0.12 (0.01) | 4.20 (0.04) | 35.1 (3.4) | 0.07 (0.01) | 35.7 (1.3) | 19.2 (1.7) | 45.1 (2.8) | 4.0 (0.8) | 44.5 (8.8) | 51.4 (9.5) | 5 |
| AABW | 0.15 (0.01) | 5.64 (0.08) | 36.8 (6.0) | 0.11 (0.01) | 37.2 (1.0) | 17.7 (0.4) | 44.1 (0.6) | 5.8 (1.6) | 53.0 (10.3) | 41.2 (11.8) | 3 |
| EASTERN SECTION | |||||||||||
| 100 m | 1.45 (0.27) | 38.84 (1.88) | 25.8 (7.3) | 90.32 (35.28) | 30.1 (6.2) | 14.3 (2.7) | 55.6 (3.5) | 13.2 (2.8) | 52.6 (16.1) | 34.2 (16.4) | 4 |
| OMZ | 0.82 (0.28) | 10.48 (0.36) | 13.1 (4.2) | 3.74 (1.64) | 37.3 (6.2) | 8.2 (0.8) | 54.4 (5.5) | 10.7 (2.3) | 44.6 (25.3) | 44.7 (24.8) | 4 |
| AAIW | 0.33 (0.02) | 4.61 (0.14) | 13.9 (4.3) | 0.37 (0.08) | 36.2 (1.3) | 10.8 (1.2) | 53.0 (0.4) | 10.2 (1.1) | 40.6 (17.6) | 49.2 (18.2) | 4 |
| UNADW | 0.17 (0.02) | 2.28* (0.10) | 13.0* (4.8) | 0.06 (0.02) | 36.6 (1.9) | 15.7 (0.3) | 47.7 (1.6) | 7.1 (4.3) | 13.5* (7.2) | 79.4* (11.4) | 4 |
| LNADW | 0.12 (0.01) | 4.69 (0.04) | 38.2 (3.2) | 0.04 (0.01) | 37.7 (1.4) | 16.9 (0.8) | 45.4 (1.9) | 8.5 (0.5) | 71.3 (0.5) | 20.2 (0.8) | 4 |
| AABW | 0.13 (0.01) | 5.04 (0.04) | 40.7 (6.1) | 0.04 (0.01) | 37.1 (1.9) | 19.6 (1.2) | 43.4 (2.6) | 9.7 (0.7) | 56.8 (18.4) | 33.5 (18.2) | 4 |
Numbers in bold without and with an asterisk show significant differences (p ≤ 0.05 or p ≤ 0.01, respectively) of individual parameters between the Vema Fracture Zone and the northern and eastern stations. Abbreviations: 100 m, bottom of euphotic layer; HNA-HS, percentage of high nucleic acid prokaryotes with high scatter; HNA-LS, percentage of high nucleic acid prokaryotes with low scatter; LNA, percentage of low nucleic acid prokaryotes; N, number of samples; PA, prokaryotic abundance; PHP, prokaryotic heterotrophic production measured by leucine incorporation rate; VA, viral abundance; VirHigh, percentage of high fluorescent viruses; VirLow, percentage of low fluorescent viruses; VirMed, percentage of medium fluorescent viruses; VPR, virus-to-prokaryotes ratio; Values are average values for all parameters except VPR. Standard deviation is given in brackets.