Table 1. Differences in variables between clusters.
Mean and standard deviation of environmental variables, species richness, and Shannon diversity between Cluster 1 and Cluster 2 samples. Prokaryotes (16S) and protists (18S) were clustered similarly (n = 16 for Cluster 1; n = 17 for Cluster 2). Replicate samples were considered for diversity metrics and varied between 16S (n = 46 and 48 for Cluster 1 and 2) and 18S (n = 47 and 49 for Cluster 1 and 2) due to removal of two 16S samples (3/16 B and 9/20 C) with low sequence read numbers. Means were compared between clusters, with significantly different variables indicated by an asterisk (Wilcoxon or paired t-tests, * p-value < 0.05; ** p-value < 0.01). Temp = temperature (°C); SiO4 = silicate (µM); NO3 = nitrate (µM); PO4 = phosphate (µM); NH4 = ammonium (µM); Chl = chlorophyll (µg L−1); Sal = salinity (psu); Solar = solar radiation (MJ m−2); POC/PON = particulate organic carbon or nitrogen (µg C or N L−1).
| Variables | Cluster 1 | Cluster 2 |
|---|---|---|
| Temp** | 16.43 (5.04) | 28.39 (1.99) |
| SiO4** | 44.83 (13.97) | 105.79 (20.90) |
| NO3** | 0.44 (0.29) | 0.98 (0.46) |
| PO4** | 0.56 (0.12) | 0.67 (0.11) |
| NH4** | 2.4 (1.4) | 1 (0.93) |
| Chl | 3.15 (1.26) | 3.79 (1.43) |
| Sal | 29.22 (1.44) | 29.36 (1.55) |
| Solar* | 9.57 (5.69) | 13.83 (3.66) |
| POC | 60.27 (30.12) | 62.83 (14.67) |
| PON | 10.8 (4.41) | 11.41 (3.4) |
| 18S richness | 488.15 (124.71) | 500.78 (77.22) |
| 18S Shannon | 4.3 (0.48) | 4.47 (0.28) |
| 16S richness** | 221.15 (67.07) | 271.73 (47.31) |
| 16S Shannon** | 4.07 (0.52) | 4.46 (0.18) |