The data were log or square root-transformed to meet the assumptions of homogeneity and normality. All response variables were affected by at least two of the factors tested. The rate of algal growth, Pnmax, dark-adapted Fv/Fm, and Rdark tended to be at their lowest values in August, and were mostly governed by the interaction of Time (August vs. November) and Scenario. Growth was enhanced by the PI treatment in November, and slightly reduced

in August in response to the A1FI treatment (three-way factorial ANOVAs, F(3,32) = 6, P < 0.002; post hoc: November-PI > Other, August-A1FI < November-PD, Fig. 1). CX-4945 The average values for temperature and pCO2 were 26.2° ± 0.9°C (mean ± SD) and 990 ± 175, respectively, under LY2109761 August-A1FI treatments, and 24.4° ± 0.9°C and 345 ± 47, respectively, under November-PI treatments (Table 1). Weekly growth rates, calculated as an average between August and November experiments, decreased with increasing temperature and acidification

offsets, and was lowest under A1FI treatment (+4.0°C, +681 μatm) and highest under the PI treatment (−1°C, −100 μatm). The mean dark-adapted Fv/Fm showed a significant temporal effect and an interaction between Time × Scenario (Fig. 2; Table 2). This interaction (three-way factorial ANOVA, F(3,32) = 4, P = 0.02) led to significantly elevated dark-adapted Fv/Fm in November PI grown algae compared to either August-PI or August-A1FI grown algae (Fig. 2). Pnmax (μmol · h−1 · gfw−1) was governed by Scenario (Fig. 2, three-way factorial ANOVA, F(3,32) = 5.3, P = 0.004; Table 2). Pnmax was greatest under A1FI, having significantly higher values than those obtained under PD and PI scenarios. The response of algal Rdark (μmol · h−1 · gfw−1) was dominated by a three-way

Isotretinoin interaction (Fig. 2, three-way factorial ANOVA, F(3,32) = 4.2, P = 0.01; Table 2). As a main effect, algae grown under the November-A1FI scenario had significantly higher dark respiration rates than algae grown under November-PI and November-PD scenarios (two-way factorial ANOVA, F(3,16) = 5.2, P = 0.01; Table 2). However, a weak interaction between Nutrients and Scenario led to increased respiration under A1FI ambient nutrients compared with the nutrient enriched PI and ambient nutrient PD thalli (two-way factorial ANOVA, F(3,16) = 3.5, P = 0.04; Table 2). In August, an interaction between Scenario and Nutrients led to opposing effects. This interaction had a tendency to lead to reduced Rdark under ambient nutrients combined with PD or PI scenarios, but nutrient enrichment increased Rdark under these same scenarios. Under B1 and A1FI scenarios, nutrient enrichment led to lower respiration rates, while Rdark was increased under ambient nutrients. Pigments showed complex responses to the different treatments (Fig. 3; Table 3). Pigment responses were governed by interactions amongst the factors.