Table 1. Physicochemical and biological properties of waters used for determining the effects of light on rates of nitrification in the absence of rapidly growing phytoplankton.

	Station M1		Station M2
	30 m	60 m	30 m	60 m	200 m
Pressure	30.2	60.5	31.5	61.4	202
NO3−+NO2− (µM)	12.1	18.9	5.1	19.6	30.6
Chlorophyll (µg L−1)	0.8	0.1	1.7	B.D.†	B.D.
PAR (% of Surface)	1.5%	0.1%	6%	0.1%	<0.1%
WCA amoA (genes L−1)††	4×106	4×106	1×106	6×106	6×106
WCB amoA (genes L−1)	9×104	2×105	9×103	3×104	4×106
AOB amoA (genes L−1)	2×105	3×105	9×104	5×104	2×104
WCA amoA (mRNA L−1)	4×105	3×105	6×104	2×106	1×106
WCB amoA (mRNA L−1)	2×103	5×103	B.D.†	3×104	3×105
AOB amoA (mRNA L−1)	8×104	2×104	6×103	5×104	B.D.

^†B.D, below detection (<0.01 µg L⁻¹ chlorophyll or <10 copies per qPCR reaction for AOB amoA).

^††Gene and transcript abundances obtained by qPCR were normalized to the volume of seawater filtered.