Fig. 9.

Mean catalase activity of tadpoles in ambient and elevated CO₂ treatments. U mg^− 1 – Units of catalase per mg of protein in the sample. Amount of catalase needed to degrade 1 μmol of H₂O₂ per min. is equivalent to one Unit. Control – Ambient CO₂ and water temperature at 29 ± 1 °C; ECO2 – CO₂ bubbled to water to maintain pH at 5.5–5.6. Error bars which are not overlapping indicate means are not significantly different at p = 0.05