Ocean acidification stress index for shellfish (OASIS): Linking Pacific oyster larval survival and exposure to variable carbonate chemistry regimes

Understanding larval bivalve responses to variable regimes of seawater carbonate chemistry requires realistic quantification of physiological stress. Based on a degree-day modeling approach, we developed a new metric, the ocean acidification stress index for shellfish (OASIS), for this purpose. OASIS integrates over the entire larval period the instantaneous stress associated with deviations from published sensitivity thresholds to aragonite saturation state (ΩAr) while experiencing variable carbonate chemistry.

We measured survival to D-hinge and pre-settlement stage of four Pacific oyster (Crassostrea gigas) cohorts with different histories of carbonate chemistry exposure at the Whiskey Creek Hatchery, Netarts Bay, OR, to test the utility of OASIS as a stress metric and document the effects of buffering seawater in mitigating acute and chronic exposure to ocean acidification. Each cohort was divided into four groups and reared under the following conditions: 1) stable, buffered sea...