TABLE 1.
Sample and station characteristics of the locations physically visited in this study
| Characteristic | CB-15-surfa | CB-15-SCM | PP-2-SCM | CB-9-SCMb | L9-SCMb | BB-5-SCMb | BB-8-SCMb | NP-12-SCMb | SLIP-4-SCMb |
|---|---|---|---|---|---|---|---|---|---|
| Sampling characteristics | |||||||||
| Region | CB | CB | CB | CB | NBB | BB | BB | AGyre | BerS |
| Date of sampling | 14 August 2007 | 14 August 2007 | 20 August 2007 | 10 August 2007 | 19 August 2005 | 12 July 2007 | 13 July 2007 | 10 July 2008 | 16 July 2008 |
| Latitude (°N) | 76.969 | 76.969 | 75.845 | 77.934 | 77.833 | 68.831 | 68.091 | 53.712 | 63.003 |
| Longitude (°E) | −140.075 | −140.075 | −128.642 | −149.826 | −75.346 | −61.760 | −64.006 | −156.126 | −173.456 |
| Depth of sampling (m) | 5 | 57 | 70 | 47 | 27 | 28 | 40 | 50 | 28 |
| Physicochemical characteristics | |||||||||
| Salinity | 24.11 | 31.13 | 30.91 | 30.71 | 31.88 | 32.70 | 32.44 | 32.71 | 32.70 |
| Temperature (°C) | −0.83 | +0.27 | −1.15 | −0.41 | +1.11 | −1.56 | −1.18 | +5.14 | −1.39 |
| Nitrate level (μM) | bd | 5.6 | 4.3 | 0.7 | —c | 5.4 | 1.4 | 12.3 | 10.4 |
| Phosphate level (μM) | 0.55 | 1.27 | 1.19 | 0.63 | — | 0.97 | 0.78 | 1.31 | 1.77 |
| Silicate level (μM) | 2.4 | 12.4 | 9.9 | 5.6 | — | 9.2 | 2.9 | 24.5 | 26.7 |
| Biological characteristics | |||||||||
| Total chl a level (μg liter−1) | 0.03 | 0.32 | 0.13 | 0.29 | 1.87 | 0.68 | 2.25 | 0.23 | 0.45 |
| Chl a large fraction (>3 μm) (%) | 29 | 42 | 10 | 27 | 87 | 25 | 95 | — | 24 |
| DNA 18S pyrosequencing (no. of OTU0.98nt) | 1,063 | 1,018 | 1,173 | — | — | — | — | — | — |
| RNA 18S pyrosequencing (no. of OTU0.98nt) | 1,296 | 1,087 | — | — | — | — | — | — | — |
| DNA 18S clones (no. of OTU0.99nt) | 16 | 12 | 15 | — | — | — | — | — | — |
| RNA 18S clones (no. of OTU0.99nt) | 18 | 14 | 7 | — | — | — | — | — | — |
| DNA NR clones (no. of OTU0.94aa) | 8 | 2 | 3 | 2 | 4 | 5 | 10 | 5 | 4 |
| RNA NR clones (no. of OTU0.94aa) | 3 | 2 | 5 | 4 | — | 4 | 3 | 5 | 2 |
a
CB, Canada Basin; surf, surface waters; AGyre, Alaskan Gyre; BerS, Bering Sea; (N)BB, (northern) Baffin Bay; bd, below detection; NR, nitrate reductase; OTU0.98nt, 18S pyrosequencing OTUs clustered at 98% nucleotide identity; OTU0.99nt, 18S clone OTUs clustered at 99% nucleotide identity; OTU0.94aa, NR clone OTUs clustered at 94% amino acid identity; SCM, subsurface chlorophyll a maximum.
b
NR-only samples.
c
—, missing data.