Table 3. Distribution of the 26 major OTUs.
| Percentage (%) of major OTUs in the sampling sites | ||||||||||||||||
| OTUs | SW1 | SW2 | SW3 | SW4 | SW5 | SW6 | SW7 | SW8 | SW9 | MP1 | MP2 | MP3 | MP4 | IB | IT | Phylotypes |
| (30.2) | (30.5) | (28.9) | (28.8) | (26.5) | (26.6) | (26.4) | (25.5) | (27.6) | (26.0) | (26.0) | (26.0) | (13.0) | (2.4) | (1.6) | ||
| ARC1 | 24.3 | 50.9 | 54.4 | 57.0 | 65.0 | 49.4 | 63.0 | 45.4 | 36.8 | 45.1 | 46.8 | 48.7 | 3.4 | 7.8 | 1.9 | SAR11 group I (AP) |
| ARC2 | 4.5 | 3.4 | 5.9 | 0.0 | 8.5 | 0.0 | 10.4 | 12.0 | 15.3 | 12.7 | 11.3 | 12.2 | 0.8 | 3.5 | 0.7 | RCA clade (AP) |
| ARC3 | 0.0 | 0.0 | 4.9 | 4.1 | 0.0 | 7.6 | 1.7 | 3.9 | 0.0 | 1.9 | 2.6 | 1.9 | 0.0 | 0.4 | 0.0 | SAR86 clade (GP) |
| ARC4 | 0.2 | 0.3 | 1.2 | 1.0 | 2.1 | 4.3 | 3.6 | 4.4 | 2.6 | 2.7 | 3.4 | 3.3 | 0.0 | 0.0 | 0.0 | SAR11 group III (AP) |
| ARC5 | 0.3 | 0.1 | 2.9 | 3.2 | 4.2 | 7.4 | 2.1 | 2.7 | 2.0 | 3.1 | 2.0 | 1.9 | 0.0 | 0.4 | 0.1 | SAR86 clade (GP) |
| ARC6 | 18.3 | 6.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | Polaribacter (FB) |
| ARC7 | 3.3 | 2.0 | 3.9 | 4.9 | 2.3 | 2.0 | 0.0 | 1.2 | 3.0 | 0.6 | 0.5 | 0.4 | 0.0 | 0.0 | 0.0 | Arctic96BD-19 clade (GP) |
| ARC8 | 0.3 | 0.5 | 0.4 | 0.7 | 0.2 | 0.8 | 3.8 | 1.0 | 3.3 | 3.5 | 4.3 | 4.3 | 0.0 | 1.2 | 0.3 | SAR11 group II (AP) |
| ARC9 | 10.5 | 7.8 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.1 | 0.0 | 2.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | Balneatrix (GP) |
| ARC10 | 1.3 | 1.0 | 5.2 | 1.3 | 0.0 | 1.0 | 0.4 | 1.5 | 0.0 | 1.7 | 0.6 | 1.8 | 0.0 | 0.0 | 0.0 | SAR86 clade (GP) |
| ARC11 | 2.1 | 2.3 | 0.1 | 0.4 | 1.3 | 3.7 | 0.0 | 1.8 | 0.9 | 0.7 | 0.7 | 0.3 | 0.0 | 0.0 | 0.0 | NS5 marine group (FB) |
| ARC12 | 0.0 | 0.0 | 1.7 | 2.3 | 0.7 | 3.4 | 0.6 | 0.8 | 0.7 | 1.2 | 0.9 | 1.0 | 0.0 | 0.2 | 0.0 | SAR11 clade, Surface 4 (AP) |
| ARC13 | 0.5 | 0.0 | 3.5 | 3.3 | 0.0 | 0.6 | 0.1 | 1.5 | 0.0 | 0.0 | 0.1 | 0.5 | 0.0 | 0.0 | 0.0 | SAR92 clade (GP) |
| ARC14 | 0.9 | 0.1 | 0.0 | 0.6 | 2.6 | 0.2 | 1.7 | 4.8 | 2.4 | 4.6 | 4.3 | 4.3 | 0.0 | 0.9 | 0.2 | unknown |
| ARC15, ARC23 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.0 | 14.5 | 28.4 | Octadecabacter (AP) |
| ARC16 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.3 | 4.7 | 4.5 | CandidatusEndobugula(GP) |
| ARC17, ARC26 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 7.9 | 11.8 | Bacillus (GPB) |
| ARC18 | 0.0 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 10.4 | 0.0 | 0.0 | Polaribacter (FB) |
| ARC19 | 0.0 | 0.0 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.0 | 0.2 | 0.0 | 0.0 | 2.6 | 4.1 | Actinobacteria (GPB) |
| ARC20, ARC24 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 31.5 | 0.7 | 3.4 | Polaribacter (FB) |
| ARC21 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.6 | 0.0 | BD7-8 Marine group (GP) |
| ARC22 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.3 | 0.0 | 0.2 | 0.2 | 26.5 | 11.2 | 17.0 | Persicivirga (FB) |
| ARC25 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 9.9 | 4.1 | 4.8 | Glaciecola (GP) |
| Minor groups | 33.5 | 25.4 | 15.7 | 21.2 | 13.1 | 19.6 | 12.6 | 17.9 | 32.6 | 18.8 | 22.1 | 19.2 | 16.2 | 34.3 | 22.8 | |
The 26 OTUs accounted for more than 1% in each sample, and the minor groups denote the sum of rare OTUs that were arbitrarily defined as having a frequency of <1% within a sample. Numbers in parentheses indicate the salinity of each sample. Abbreviations in parentheses: GP, Gammaproteobacteria; AP, Alphaproteobacteria; FB, Flavobacteria; GPB, Gram-positive bacteria.