Table 1. Pearson's correlation analyses of mean virioplankton abundance versus the biogeochemical variables of nitrate (μmol kg⁻¹; 2000–2008), phosphate (μmol kg⁻¹; 2000–2008), Chl-a (μg kg⁻¹; 2000–2007), DOC (μmol kg⁻¹; 2000–2008), PP (mg m⁻³ per day; 2000–2008) and BP (mg m⁻³ per day; 2000–2008).

All data	MLD <50 m	MLD >50 m
January–December	May–November	December–April
Nitrate
r=−0.24	r=−0.26	r=−0.15
n=118	n=58	n=60
Phosphate
r=−0.08	r=−0.05	r=−0.09
n=118	n=58	n=60
Chl-a
r=−0.20	r=0.08	r=−0.28
n=95	n=47	n=48
DOC
r=0.12	r=0.13	r=0.11
n=112	n=57	n=55
PP
r=0.19	r=0.15	r=0.03
n=107	n=54	n=53
BP
r=0.13	r=0.10	r=−0.19
n=96	n=50	n=46

Abbreviations: BP, bacterial production; DOC, dissolved organic carbon; MLD, mixed layer depth; PP, primary production.

Mean values were first determined by integrating variable between 60 and 100 m and normalizing to integration depth. All correlations were significant at P-values of <0.0001; n equals the number of pairwise comparisons. Correlation values are reported for all mean data between 60 and 100 m, and for subsets where the MLD <50 m and MLD >50 m.