Figure 2. Species–specific growth response to treatment conditions.

The mean (±SE) change in either fleshy or calcareous biomass following exposure to either present-day ambient air controls (open circles) or predicted OA treatments (closed circles) for species tested in multiple experiments. The dashed line is positioned at zero to indicate relative growth or loss of tissue for (A) Halimeda opuntia, (B) Halimeda taenicola, (C) Lithophyllum sp., and (D) Caulerpa serrulata. Fleshy macroalgae are shown in brown, upright calcareous algae in green, and CCA in red. * Indicates a significant difference between treatments as determined by independent t-tests (results reported in Table 3).