Electronic Supplementary Material s38

Electronic Supplementary Material

Ocean acidification and rising temperatures may increase biofilm primary productivity but decrease grazer consumption: evidence from a mesocosm experiment

Bayden D. Russell, Sean D. Connell, Helen S. Findlay, Karen Tait, Stephen Widdicombe, Nova

Mieszkowska

1 Table S1. Summary of an ANOVA testing for the combined effects of time of pre-exposure

of Grazer to experimental conditions (2-week v. 5-month exposed), Temperature (14 v.

18 ºC) and CO2 (380 v. 750 v. 1000 ppm) on the percentage cover of biofilm consumed

during the experiment. Significant p-values in bold.

Source of variation Sum of squares df Mean squares F P Grazer 4824.38 1 4824.38 20.76 0.0001 Temperature 634.14 1 634.14 2.73 0.1072 CO2 3127.24 2 1563.62 6.73 0.0033 Grazer × Temperature 605.11 1 605.11 2.60 0.1153 Grazer × CO2 545.98 2 272.99 1.17 0.3204 Temperature × CO2 335.51 2 167.75 0.72 0.4927 Grazer × Temperature × CO2 229.42 2 114.71 0.49 0.6145 Residual 8365.45 36 232.37

2 Table S2. Summary of ANOVAs testing for the combined effects of Temperature (14 v.

18 ºC) and CO2 (380 v. 750 v. 1000 ppm) on the percentage cover of biofilm consumed by (a)

5-month and (b) 2-week pre-exposed grazers during the experiment. Significant p-values in

Source of variation Sum of squares df Mean squares F P (a) 5-month pre-exposed Temperature 1239.08 1 1239.09 4.68 0.044 CO2 3138.29 2 1569.15 5.92 0.011 Temperature × CO2 534.02 2 267.01 1.01 0.385 Residual 4768.72 18 264.93 (b) 2-week pre-exposed Temperature 0.17 1 0.17 0.00 0.977 CO2 267.47 2 267.47 1.34 0.287 Temperature × CO2 15.46 2 15.46 0.08 0.926 Residual 199.82 18 199.82

3 Table S3. Summary of an ANOVA testing for the combined effects of Temperature (14 v. 18

-1 -1 ºC) and CO2 (380 v. 750 v. 1000 ppm) on the metabolic rates (μmol O2.g .h ) of Grazers pre-

exposed for different times (2-week v. 5-month pre-exposed). Significant p-values in bold.

Source of variation Sum of squares df Mean squares F P Grazer 0.002 1 0.002 0.03 0.844 Temperature 0.233 1 0.233 4.25 0.047 CO2 0.021 2 0.105 0.19 0.827 Grazer × Temperature 0.005 1 0.005 0.09 0.758 Grazer × CO2 0.112 2 0.056 1.02 0.383 Temperature × CO2 0.150 2 0.075 1.37 0.265 Grazer × Temperature × CO2 0.005 2 0.002 0.04 0.953 Residual 1.532 28 0.055

4 Table S4. Summary of an ANOVA testing for the combined effects of Temperature (14 v.

18 ºC) and CO2 (380 v. 750 v. 1000 ppm) on the percentage cover of biofilm on ungrazed

settlement panels. Significant p-values in bold.

Source of variation Sum of squares df Mean squares F P (a) Acclimatized Temperature 7920.67 1 7920.67 48.22 <0.0001 CO2 700.00 2 350.00 2.13 0.1477 Temperature × CO2 208.44 2 104.22 0.63 0.5417 Residual 2956.89 18 164.27