TABLE 1.

Principal coordinate analysis (PCoA) and permutation test analyzing the correlation between environmental variables and beta diversity.

	Surface_FL		Surface_PA		CIL_FL		CIL_PA
Variable tested	R2	p-value	R2	p-value	R2	p-value	R2	p-value
Salinity	0.8	0.006**	0.191	0.535	0.801	0.001***	0.471	0.104
Temperature	0.82	0.005**	0.583	0.078*	0.275	0.380	0.407	0.173
Chl a	0.2	0.402	0.010	0.975	0.45	0.215	0.450	0.182
NO3–	0.55	0.136	0.114	0.712	0.841	0.008**	0.345	0.254
NO2–	0.56	0.124	0.157	0.589	0.112	0.746	0.129	0.675
PO43–	0.7	0.117	0.323	0.333	0.812	0.007**	0.469	0.162
NH4+	0.96	0.116	0.529	0.215	0.306	0.344	0.220	0.507
SiO2–	0.89	0.003**	0.254	0.409	0.898	0.001***	0.409	0.217
DOC	0.53	0.093	0.342	0.287	0.035	0.865	0.202	0.434
HNA	0.07	0.866	0.392	0.243	0.002	0.991	0.080	0.813
LNA	0.34	0.272	0.819	0.007**	0.563	0.150	0.091	0.702

Individual communities surveyed are defined by depth (surface or cold intermediate layer: CIL) and size-fractionation (free living: FL or particle-attached: PA). Signif. codes: ***P < 0.001, **P < 0.01, *P < 0.1; Number of permutations: 999. DOC, Dissolved organic carbon; NH4-N, Ammonium; NO₂-N, Nitrite; NO₃-N, Nitrate; PO₄-P, Phosphate; SiO₂, Silica; HNA, bacterial cells with high nucleic acid content; LNA, bacterial cells with low nucleic acid content.