Table 2. Results of light inhibition experiments, when waters from dark or dimly lit depths, where phytoplankton growth was minimal, were exposed to the irradiance and photoperiod of the surface layer or held in complete darkness for 24 h.

Station	Depth (m)	Nitrification (nmol L−1 d−1)
		50% light	Dark
M1	30	93.9±1.5†	83.7±2.9
	60	94.5±0.4	106.2±0.2
M2	30	14.8±0.6	19.5±1.7
	60	86.3±2.9	77.2±7.0
	200	14.7±0.2	11.2±1.3

^†Values represent the mean ± standard deviation of duplicate samples at each depth (N = 2).