to allow adaptation at the expected rate and magnitude of future pH/pCO2 changes. It is conceivable that some reef calcifiers or cold water corals could adapt to ocean acidification if they evolve a calcification mechanism that allows them to precipitate CaCO3 at normal rates, but this type of adaptation has not been documented in corals. Survival of these organisms depends on their capacity to cope with skeletal loss by a change in life history (i.e., shift to cryptic existence), defenses (e.g., toxin production), or other means. Adaptation to compensate for weaker or smaller skeletons has not been demonstrated, but this topic has barely been investigated (e.g., Bibby et al., 2007).
The persistence of various taxa under increasing ocean acidification will depend on either the capacity for acclimation (plasticity in phenotype within a generation) or adaptation (plasticity in genotype over successive generations) or a combination of both. The relative capabilities of various taxa in terms of both acclimation and adaptation will likely influence the composition of marine communities and therefore result in a range of consequences for marine ecosystems.