Although ocean acidification is generally predicted to be deleterious to marine life, not all taxa and species respond similarly to future conditions [18]. There is emerging evidence that an organism’s pH-exposure history can influence its tolerance of ocean acidification. For example, Ref. 19 showed that an Arctic copepod species that experienced varied depth-dependent pH exposure was more tolerant of CO2-acidified seawater treatments compared to another Arctic copepod species that experiences a smaller range in pH. Comprehensive characterization of the ‘pH-seascape’ is thus necessary to link CO2-perturbation experiments with present-day and future organismal performance in the field. Such field time-series are sparse in near-shore Antarctica and are either extremely short [20,21] or low in sampling frequency [7,8,12].