Table 2. Concentrations of phenolic substances in the “long” form of widgeon grass subjected to Free Ocean Carbon Enrichment within the St. Mary's River, Maryland (USA) in May-July 2010.

Conditions	Seawater carbonate chemistry
Distance from injector	500cm	40cm	5cm
Temperature (C)	25.0	25.0	25.0
Salinity	17	17	17
pH	8.4	8.0	6.9
pCO2 (µtm)	157.8	469.3	6792.0
TA (µmol kg−1)	1467.0	1444.0	1455.0

Values are means +/− SE.

Statistical analyses: 1, one-factor ANOVA with Holm-Sidak multiple comparisons; 2, Kruskal-Wallis One Way Analysis of Variance on Ranks with Tukey or Dunns multiple comparisons. Letters indicate results of pairwise comparisons test P<0.05.