Table I:

Noon time values of PAR and results of the paired t-tests depicting the significance of differences in picoplankton Chl a and nano + microplankton Chl a between Control, Si and light-treated samples from experiments at Cycles 2–4 and from trace metal experiments (TME) at Cycle 3

Noon-time PAR	Cycle 2			Cycle 3			Cycle 4			TME
	125–1029 µE m−2 s−1			600–1209 µE m−2 s−1			240–1252 µE m−2 s−1			600–1209 µE m−2 s−1
Treatment	HL-Con	HL + Si	LL-Con	HL-Con	HL + Si	LL-Con	HL-Con	HL + Si	LL-Con	Treatment	Zn	Fe	Si
Picoplankton
HL + Si	0.13			0.63			0.11			Fe	0.34
LL-Con	0.19	0.042a		0.37	0.43		0.35	0.13		Si	0.13	0.018a
LL + Si	0.54	0.043a	0.09	0.67	0.63	1.00	0.63	0.63	0.70	Con	0.13	0.030a	0.016a
	HL-Con	HL + Si	LL-Con	HL-Con	HL + Si	LL-Con	HL-Con	HL + Si	LL-Con		Zn	Fe	Si
Nano + Microplankton
HL + Si	0.18			0.61			0.26			Fe	0.34
LL-Con	0.56	0.072a		0.37	0.75		0.09a	0.09a		Si	0.68	0.46
LL + Si	0.19	0.096a	1.00	0.42	0.99	0.50	0.1a	0.13	0.63	Con	0.79	0.22	0.65

Grey-shaded values indicate data that failed the normality and equal variance tests. Data for Days 0 and 8 were excluded from this analysis.

^aA significant difference at P < 0.1 level.