Experiments on contemporary marine organisms have demonstrated many negative responses to elevated CO2 levels, i.e., conditions that could occur in the average open ocean within the next 300 years. This has led to the recognition of ocean acidification (OA) as a key anthropogenic stressor and to concerns about detrimental changes to marine ecosystems on which humans depend. While assessing species sensitivities to OA has been the necessary first step, the gradual nature of these shifts further demands that we assess how transgenerational plasticity and evolutionary adaptation to OA will likely affect the overall vulnerability of species and ecosystems. Our predictive ability of these adaptive processes is still in its infancy.

The overview talk first looked at currently employed approaches to study adaptation, from relatively well-documented in vitro evolution to OA in single cell organisms to necessarily more inferential techniques (e.g., evolutionary potential, standing genetic variation, molecular techniques) in longer-lived metazoans where multi-generational experiments are largely unfeasible. Secondly, the talk touched on the likely role of transgenerational plasticity in mitigating adverse OA effects over shorter time-scales in some species and whether this could perhaps compromise their ability to genetically adapt. The final objective was to pose a number of largely unresolved questions (e.g., selection differentials? Evolutionary trade-offs?) and highlight a few, perhaps underutilized approaches (e.g., studying spatial gradients as analogies to temporal change) that might improve understanding of evolution and plasticity to OA.