Table 3. Percent decrease of the marker pigment concentrations (mean ± standard deviation of triplicate microcosms, and the probability) treated with 1.6 mg L⁻¹ H₂O₂, as compared to the control without H₂O₂ addition, in microcosms with unfiltered and 5-μm filtered seawater.

	Fucoxanthin	Chl b	Peridinin	Zeaxanthin
Microcosms with unfiltered seawater
0 hr	2±3% (0.248a)	3±4% (0.452)	N.A.	15±5% (0.023)
24 hr	55±2% (0.006)	53±2% (0.007)	34±5% (0.010)	17±12% (0.136)
48 hr	44±1% (0.000)	58±1% (0.001)	18±18% (0.292)	N.A.
72 hr	−104 b±3% (0.003)	8±9% (0.018)	N.A.	48±8% 0.012)
Microcosms with 5 μm filtered seawater
0 hr	4±4% (0.224)	0±6% (0.939)	22±15% (0.289)	0±9% (0.978)
24 hr	60±7% (0.002)	54±6% (0.003)	N.A.	N.A.
48 hr	57±5% (0.002)	67±2% (0.003)	N.A.	N.A.
72 hr	−66 b±5% (0.000)	17±4% (0.018)	N.A.	55±4% (0.010)

^aThe values in parenthesis are probabilities of the two sample t-tests; p<0.05 suggests the percent change is statistically significant. ^b A negative percentage value indicates pigment concentrations were greater in treatment microcosms than the controls. N.A^. indicates pigment quantification might not be accurate as at least one of the triplicates went below detection limit.